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Dirty-South Blues Harp forum: wail on! >
Milling Brass Combs
Milling Brass Combs
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Philosofy
534 posts
Apr 16, 2014
1:45 PM
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I've finally found a way to mill my own brass combs in my woodworking shop. I have a router table with an incra jig, and use an 11/16" carbide metal working bit. There's no way I can mass produce, and I just don't have the time, anyway. But I do have a couple questions that someone here might be able to help with.
I use 1.25" wide and 0.25" thick brass. I mill each slot in one pass. However, when I'm done milling, the comb is bowed outward. For a visual, its like if the comb was your hand, and you spread your fingers out. So the teeth of the comb would stick out in the middle holes. I have to trim them parallel on my table saw. I've been meaning to try milling the slots in 2 passes: first pass almost all the way through, leaving enough so the comb won't deform, and the second pass to finish the slot. Do you think that would work?
Also, I got my hands on some pen blank acrylic that looks pretty neat, but its only 3/4" square. I can rip it in half and glue it so its 1.5" wide, but what kind of glue should I use?
And, third question, where can I get some Corian type material to play with?
I hope someone can answer these questions without giving away trade secrets.
Thanks!
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arzajac
1344 posts
Apr 16, 2014
2:13 PM
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Phil: I played around with some brass a while ago. I took my Marine Band design and cut a few combs on my CNC mill.
I tweaked the G-Code with no idea what I was doing but I had success on the first shot. I ran my CNC mill at half speed and made 8 passes (0.8mm per pass - The vein on my forehead popped out when I read you did yours in one pass! Your combs look good - they certainly don't look like they have been through that much stress...)
You can put support bridges on the tips of your tines and corners to prevent deformation - basically what you suggest about not going all the way through, but you only do it in select spots. It's much easier to deal with that way. But that's from my perspective, where I'm not cutting this by hand...
Acrylic is relatively cheap. I think you would be much happier just starting off with a bigger piece.
Corian off-cuts, ha! It seems Richard Sleigh got legal action taken against him because he used the trademark "C0rian" on his website but only used off-cuts of the stuff. DuPont seems to be very strict about that sort of thing... But that's irrelevant if you only want to use the stuff for personal use. The vendor may get in trouble, I dunno...
I suggest you hound kitchen cabinet companies for off-cuts. In my case, I had success with the smaller companies that do the installation for big stores like Home Depot and the like. I hit the jackpot when I met the nice people at an eco-friendly building supply store. Their carpenter actually drove up on a bike to hand deliver me some samples of material!
When you tell people what this is for, most of them take a moment and, probably because it's so unusual, tend to be very helpful.
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Custom overblow harps. Harmonica service and repair.
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harpwrench
824 posts
Apr 16, 2014
2:53 PM
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arzajac- "Corian off-cuts, ha! It seems Richard Sleigh got legal action taken against him because he used the trademark "C0rian" on his website but only used off-cuts of the stuff. DuPont seems to be very strict about that sort of thing... But that's irrelevant if you only want to use the stuff for personal use. The vendor may get in trouble, I dunno..."
Andrew, Richard was never contacted by DuPont as far as I know, and I would know. And we didn't buy scraps to do them.
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www.spiersharmonicas.com
High performance harmonicas.
Last Edited by harpwrench on Apr 16, 2014 3:45 PM
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Philosofy
535 posts
Apr 16, 2014
3:47 PM
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Andrew, thanks for the praise. The problem with multiple passes on each slot is that I judge the length of the slot by eye. If it bit isn't going all the way through, I'll have to rig up some kind of stop for each slot.
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arzajac
1346 posts
Apr 16, 2014
3:56 PM
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Joe - I never said scraps - I did not mean to imply lesser-quality. Off-cuts are a very responsible way to avoid waste. I use off-cuts.
That DuPont frowns on customers who use their off-cuts puts DuPont in a bad light, in my opinion.
As for who contacted Richard Sleigh - someone did. Up until May 2012, he called it Corian on his website:
https://web.archive.org/web/20120501105840/http://rsleigh.com/corian-combs
"Our final choice was to use a pure black material that is used in making kitchen counter tops, jewelery, high end fountain pens and other items that value a luxurious and smooth look and feel.
Unfortunately this substance is made by a well known chemical company with a large legal department that is very picky about how their name is used.
So I am no longer referring to this wonderful stuff by the name I used originally to describe it. I’ll call it ”Black Magic” from now on.
Choosing a comb material has been a long, strange trip with many detours into ways of sealing stock combs, having custom combs made of exotic woods, metals, and other materials. “Black Magic” kept coming up in the radar over and over again."
(from rsleigh.com)
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Custom overblow harps. Harmonica service and repair.
Last Edited by arzajac on Apr 16, 2014 3:56 PM
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arzajac
1347 posts
Apr 16, 2014
3:59 PM
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"Andrew, thanks for the praise. The problem with multiple passes on each slot is that I judge the length of the slot by eye. If it bit isn't going all the way through, I'll have to rig up some kind of stop for each slot."
Yeah, exactly why I though you could do all in one pass but lift up by a little less than 1mm on the corners and one edge of each tine... That would create those support bridges.
But that may have it's technical challenges too since you are doing it freehand... I don't know which method would be easiest.
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Custom overblow harps. Harmonica service and repair.
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Silvertone
153 posts
Apr 16, 2014
6:02 PM
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Way to go Philosofy! Ive been thinking about trying this for a while now. Did you mean 11/64 ? Are you using a variable speed router? A simple stop shouldn't be too hard to set up especially w/ an Incra Jig. Multiple passes sounds like the right way to go about that. Im thinking a hold down jig w/ a spacer underneath for the first pass removing the spacer for the second. Post some epics if you get a chance. :)
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1847
1707 posts
Apr 16, 2014
6:18 PM
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his web site says black corian is used
then a link to blue moon where it says solid surface comb.. hmm
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i get a lot of request when i play my harmonica
"but i play it anyway"
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Philosofy
536 posts
Apr 16, 2014
8:18 PM
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Silvertone, I'll try and do a video, but be warned, I'm not a YouTube guy. Somebody might have to walk me through it.
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HarveyHarp
584 posts
Apr 16, 2014
10:41 PM
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Or perhaps printed
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HarveyHarp
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harpwrench
826 posts
Apr 17, 2014
6:09 AM
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Here's a thread related to using Corian
http://www.modernbluesharmonica.com/board/board_topic/5560960/3658670.htm
Sorry for participating in the hijack of your topic philosophy. When you cut them in one pass like that the brass expands with the heat.
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www.spiersharmonicas.com
High performance harmonicas.
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florida-trader
459 posts
Apr 17, 2014
11:24 AM
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Ahhhhhh, another comb thread. I can hear the collective groan reverberating throughout the harmonica community.
To begin with, Joe - thank you for posting the link to the thread on Dupont™ Corian® from two years ago. You saved me the trouble.
1847 – Allow me to clarify. Solid Surface is a generic term used in the counter top industry. Solid Surface is the general name used to describe the material used to make counter tops. DuPont™ Corian® is one brand of Solid Surface. There are many other companies that manufacture Solid Surface such as Wilson Art, Samsung makes a product called Staron, Hi Macs, Avonite and probably a few more. However, DuPont™ Corian® is the most recognizable name and so people have come to refer to all Solid Surface as “Corian” much the same way people say “Kleenex” when they mean tissue. So while all Corian® is Solid Surface, not all Solid Surface is Corian®. Just as all Kleenex is tissue but not all tissue is Kleenex. DuPont™ is simply smart enough to take appropriate measures to protect the investment it has made to build the reputation and brand name recognition it has created for Corian®. Hence the letter I received from them two years ago.
I offer Solid Surface combs in a variety of colors. Some of it is genuine DuPont™ Corian®; some of it is Samsung Staron; and some of it is Hi Macs. In order to not misrepresent I use the generic term Solid Surface as a category for one of the comb materials I have available. But if you dig just a little deeper and look at the color options you will find that some of them are appropriately labelled DuPont™ Corian®, some Samsung Staron and some HiMacs. And if you scroll down towards the bottom of the page you will also see that I go to great pains to explain exactly what I have stated above. There is nothing to “hmmm” about.
http://www.bluemoonharmonicas.com/items/19
And for the record, I buy remnants which are smaller pieces. Why? Because a full sheet of Solid Surface is 4’ X 9’ which would be enough to make over 700 combs. Smaller remnants afford me the option of buying lots of different colors, making smaller lots and being able offer more variety to my customers (which they seem to like).
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Tom Halchak
www.BlueMoonHarmonicas.com
Last Edited by florida-trader on Apr 17, 2014 2:24 PM
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florida-trader
460 posts
Apr 17, 2014
11:25 AM
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Moving on………..
Philosophy. Welcome to the wonderful world of milling brass. Ah yes………. Brass. It is beautiful, but what a headache to mill. I had my first brass combs made almost three years ago and every one of them warped. Good thing I only had 10 made. It took me two years of research and talking to dozens of people in the metal industry before I finally figured out how to mill brass harmonica combs and not have them warp. Up until I found the right guy who educated me, every other guy I spoke with who preceded him were just as mystified as I was. So I am sorry, that is not information I am willing to donate. I will say this though. A lot of the guys who are producing CNC milled combs are using small bench top milling machines. This is in no way a slight because after all, G code is G code and a comb milled on a bench top machine is no different than a comb milled on an industrial piece of equipment. I’m sure the combs you or Andrew make are super high quality. However metal, particularly brass, presents some challenges that a commercial piece of equipment is perhaps better suited to handle. I don’t own a CNC machine. I don’t know how to write code. Instead, I hired a professional machinist with over 30 years of experience who has at his disposal 17 different milling machines that range in cost from $50,000 to $250,000 each. The one that he uses to cut my stuff is a $150,000 machine. When he is not cutting harmonica parts, he is cutting parts for the military and the airline industry. The software program that he uses to design stuff like my recently announced External Valve Plate for the SUB-30 is a $20,000 3D Modeling Program. When we cut brass combs, we do it four at a time.
I hope this clears up some of the mystery. I got into the comb making business to provide a service to the harmonica community, make a little bit of money and to have some fun. And so far, that is pretty much what has unfolded. I am sure that most of the other hobbyists turned businessman share these sentiments.
Philosofy - you and I have exchanged numerous emails. You are Class A Gentleman and I know you have no desire to get into the comb business. I hope you don’t take offense to anything I have written because I certainly meant none. We have seen a lot of good information exchanged on this forum recently (for example Matt Smart's video on comb flatness and the conversation that ensued). Generally speaking I am happy to offer any assistance I can because most of the “trade secrets” are already out there anyway if you know where to find them. Often I am just putting in my two cents just to help make sure that any mis-information is stopped in its tracks. Occasionally though you have to draw a line and just say, “This one - I’m keeping for myself”. Yeah, I know. I’m a selfish bastard!
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Tom Halchak
www.BlueMoonHarmonicas.com
Last Edited by florida-trader on Apr 17, 2014 2:29 PM
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nacoran
7691 posts
Apr 17, 2014
1:35 PM
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STME58, wow, the spam filter whammied you! Apparently it's now set off by well informed, thoughtful, information packed posts now.
At least I'm safe!
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Nate
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STME58
772 posts
Apr 17, 2014
2:13 PM
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Thanks for restoring my post Nate! I deleted the redundant ones.
I was wondering if I should add a line like;
"Nigerian prince with ED wants to pay your low mortgage rate." in order to get it by the spam filter.
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Blowyourbrassoff
101 posts
Apr 17, 2014
3:03 PM
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"So I am sorry, that is not information I am willing to donate. I will say this though. A lot of the guys who are producing CNC milled combs are using small bench top milling machines. This is in no way a slight because after all, G code is G code and a comb milled on a bench top machine is no different than a comb milled on an industrial piece of equipment. I’m sure the combs you or Andrew make are super high quality. However metal, particularly brass, presents some challenges that a commercial piece of equipment is perhaps better suited to handle. "
As a machinist, and probably the only one making combs, I thought I'd weigh in on the subject because this is a bit misleading.
First, I use a bench top machine and have for years. It has nothing to do with the machine, absolutely nothing. Now my machine is in no longer stock or a standard off the shelf machine, but those improvements were strictly for accuracy and performance.
Second, forget about the whole cnc thing. Lets be honest, cnc is nothing more than a production tool, and big industrial machines are made to handle big industrial work. You have to know how to work with the materials and the tools you have. So honestly forget all the cnc and machine hype. Cnc is not going to ensure a better part, if your code isn't right you're part isn't going to be right.
It has to do with knowing how to work with the material, and a lot of it has to do with the alloy that you're using. I would really recommend A360 brass as it's a free machining brass and has good corrosion resistant qualities. The real issue that you're going to run into using a router to machine combs has to do with the flexibility of the router itself. It's not really meant to take the side loads that you're exposing it to when milling full depth on metal. What you need to do is mill in increments and spray a little WD-40 on it to help act as a coolant and cutting fluid. Also what kind of endmill are you using? 2 flute, 4 flute, etc? That will also make a big difference in the quality of your cut and the stress on your router. The bowing is simply a result of the cutter working to hard going through the material and generating more heat. With the router you're limited on the control you have over speed and feed. Try some A360, mill in increments, and use some kind of lubricant while cutting, I think you'll find your results improved. Keep in mind the deeper you cut the slower you must go, but because you're router runs at such a high speed you need something to keep the heat down.
As for gluing pen blanks, use CA glue
For acrylic they make a special adhesive that which essentially melts the material together.
For corian, use CA and ensure that your mating surfaces are smooth and acurate.
I don't mean to call anyone out, but this is the kind of misinformation that really is put out there to make it sound more difficult than it is. I made brass combs for the first few years before converting my mill over to cnc and then later adding flood coolant. Those are production features, not necessity. People have been machining metal of every kind for a long long time before cnc was ever invented.
Honestly you can make a really nice wood comb with a $5 coping saw and some patience. I've done it because I wanted to see if I could. Worked every bit as good as one made on my cnc milling machine. Was it accurate to .001", nope, but it doesn't need to be.
I'm going to be completely honest here. The comb is the simplest part of a harp to make. There is nothing about a harmonica comb that needs to be made out to be complicated. The only reason that it's been made out to be such a huge deal is because there are a small number of us that make combs and everyone is afraid the next guy is going to put them out of business. So it's made out to be this big deal. The reason that guys like me are able to make a living making combs is because not everyone has the time, tools, or interest in doing it. Some folks would rater just play, and you know what that's perfectly cool.
Chris
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STME58
773 posts
Apr 17, 2014
4:01 PM
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When I think of trade secrets I always think of these guys Zildjian Trade Secrets
The success of Zildjian probably has more to due with the things that were printed in the article like their careful succession plan and keeping tabs on changes in the industry, than the secret brass formula. (Here's an idea I throw out for free (and it might be worth that much)laminate some old Zildjians together and machine combs from them. They would then contain the magic Zildjian brass).
Many people seem to like to think that a person can make a living by maintaining a secret that allows the to easily do what no one else can. This is somewhat true, but the secrets are not transferred by just being told, you have to earn them. The secret to playing an instrument masterfully is to play on pitch and on time. Oops! I let it out, now everyone who reads this will be a master musician :-0
Last Edited by STME58 on Apr 17, 2014 4:16 PM
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Blowyourbrassoff
102 posts
Apr 17, 2014
4:17 PM
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Exactly, there are no trade secrets in making combs. Plain and simple. I could sit here and tell you that it takes all kinds of special knowledge, training, etc etc., but I'd be lying to you. If you have the tools, know how to use them, then you can make a comb. Make it flat, make it pretty, viola you're a comb maker.
Folks there are only two reasons to put in a custom comb...
Longevity and personalization. Better materials are going to last longer, and pretty choices allow you to personalize your harp. There's nothing wrong with wanting to dress up your harp, you're proud of it, you get lots of enjoyment from it, you paid your hard earned money for it, and wanting to dress it up and personalize it is is a natural extension of that enjoyment. But if it's a bad playing harp a new comb isn't going to turn it into a great harp.
Chris
Blowyourbrassoff.com
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Buzadero
1187 posts
Apr 17, 2014
4:19 PM
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Tommy the Trader's brass combs are bad ass.
~Satisfied Customer
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~Buzadero
Underwater Janitor, Patriot
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Blowyourbrassoff
103 posts
Apr 17, 2014
4:22 PM
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I'm not saying they aren't, but that still doesn't change the fact that this notion of trade secrets is bogus.
Chris
Blowyourbrassoff.com
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Blowyourbrassoff
104 posts
Apr 17, 2014
4:54 PM
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The only brass I know of that's lead free is Naval Brass, but looking at all the brass combs out there you can tell it's not naval brass from the color and finish. If lead is a concern for you I wouldn't buy a brass comb period. That's the only way you're going to avoid it entirely.
The heat treatment of non-ferrous metals is the opposite of heat treatment for ferrous metals. A piece of steel will harden when cooled rapidly, a piece of brass will harden as it's cooled slowly. If you need to soften a piece of brass you would heat it and let it cool down slowly.
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Blowyourbrassoff
105 posts
Apr 17, 2014
4:56 PM
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It seems we've kind of hijacked the guys thread. Sadly I take blame for that one. But I did feel the need to try and put to rest some of the misinformation out there.
Chris
Blowyourbrassoff.com
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florida-trader
461 posts
Apr 17, 2014
5:30 PM
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Chris. Thanks for taking the time to contribute to this post. As I stated earlier I am not a machinist. You have probably forgotten more about machining than I know. If I disseminated any information that was not accurate I can assure it was not intentional and I apologize. I would not have even responded to this post if my name or company name did not come up in conversation. That said I am confused by some of your statements. Perhaps you can enlighten me.
The OP stated in response to arzajac, “Andrew, thanks for the praise. The problem with multiple passes on each slot is that I judge the length of the slot by eye. If it bit isn't going all the way through, I'll have to rig up some kind of stop for each slot.” So it would seem that Phillip is not even using CNC.
I stated” A lot of the guys who are producing CNC milled combs are using small bench top milling machines. This is in no way a slight because after all, G code is G code and a comb milled on a bench top machine is no different than a comb milled on an industrial piece of equipment.
You stated” Cnc is not going to ensure a better part, if your code isn't right you're part isn't going to be right.”
So it would seem that we are in agreement on this point.
I also wrote, “However metal, particularly brass, presents some challenges that a commercial piece of equipment is perhaps better suited to handle.”
You wrote, “The real issue that you're going to run into using a router to machine combs has to do with the flexibility of the router itself. It's not really meant to take the side loads that you're exposing it to when milling full depth on metal.” So it seems to me again that we are mostly in agreement although I know that your main point was the stress of making too deep of a cut on one pass. My point was simply that a larger commercial machine is “perhaps” better suited to cut metal.
You also stated, “What you need to do is mill in increments and spray a little WD-40 on it to help act as a coolant and cutting fluid.”
I think we are all pretty much in agreement that heat is the enemy of metal during the milling process. More heat = greater likelihood of warping.
Is it your opinion that spraying a little WD40 on a machine (a router) that is not specifically designed to machine metal (and possibly using a bit that is not designed to cut metal) is comparable to this?
And finally, I did not say that there were trade secrets. That was part of the OP’s question which I believe was somewhat in jest. Information that I choose not to disclose personally does not constitute a trade secret. It is a Blue Moon secret.
P.S. Treads get hijacked all the time. It is the nature of the beast.
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Tom Halchak
www.BlueMoonHarmonicas.com
Last Edited by florida-trader on Apr 17, 2014 5:33 PM
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STME58
774 posts
Apr 17, 2014
5:38 PM
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Chris,
I think I understand where you are comming from, but to say "this notion of trade secrets is bogus" is a little extreme. I don't think it is bogus, just misunderstood and sometimes used to more of a marketing advantage than perhaps it should be.
In a previous post you stated, " If you have the tools, know how to use them", This may seem trivial to you, as one who has tools and knows how to use them, but it is not. I see this as the real trade secret. it can not be gained cheaply, you have to work for it.
I also liked what Tom said, " most of the “trade secrets” are already out there anyway if you know where to find them". The real trade secrets are diligence, perseverance, a willingness to learn, not letting your ego get in the way of the truth, etc. That is not to say there are not some hidden facts that if you know them, can shorten the path a bit. but if you have the dedication you will acquire the real "trade secrets" with or without someone letting you in on a secret in the more commonly understood sense.
Last Edited by STME58 on Apr 17, 2014 5:41 PM
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STME58
775 posts
Apr 17, 2014
5:40 PM
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I would not worry too much about lead in brass. That would only be a problem with something you were going to stick in your mouth.
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arzajac
1349 posts
Apr 17, 2014
5:49 PM
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Chris, what a pleasure it is to read your posts. Thank you!
Not that I have any interest in producing brass combs, but I am curious... With respect to 2-flute versus 4-flute, I would assume that you would use 2-flute at higher speeds than 4-flute (both feed rate and spindle speed) but what's optimal for 360 brass? It took me a while to figure out the optimal parameters for milling Paperstone. I burned out bits like crazy before I started using water coolant and even set fire to my shop! I reckon that there is a sweet spot with brass, too.
"Folks there are only two reasons to put in a custom comb...
Longevity and personalization. Better materials are going to last longer, and pretty choices allow you to personalize your harp. There's nothing wrong with wanting to dress up your harp, you're proud of it, you get lots of enjoyment from it, you paid your hard earned money for it, and wanting to dress it up and personalize it is is a natural extension of that enjoyment. But if it's a bad playing harp a new comb isn't going to turn it into a great harp. "
That view is very compatible with my view on combs. I was a staunch "you don't need to use a custom comb" guy a while back.
While putting in a new comb won't make a stock harp play better, if you are working on your harp the improve it, an airtight comb is an important part of the overall work.
All stock combs can be made to be very airtight. So the world would still be a wonderful place if no custom combs existed. But sometimes using a comb made from a water-resistant and easily flattened material can save a lot of time and effort in comparison to the work that needs to be done to the stock comb.
To me, that's the value in custom combs. And they last forever and they look nice.
"you can make a really nice wood comb with a $5 coping saw and some patience"
The thought never occurred to me! Is it just me or does that sound like a fun project?
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Custom overblow harps. Harmonica service and repair.
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Blowyourbrassoff
106 posts
Apr 17, 2014
6:16 PM
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First off so there's no confusion my post wasn't directed at Tom as much as the notions that have been put out there for years.
I'm not trying to put you down at all Tom, I'm only trying to dispel some of the inaccuracies that get put out there. For example "Ah yes………. Brass. It is beautiful, but what a headache to mill. I had my first brass combs made almost three years ago and every one of them warped." Brass is one of the easiest metals to machine, if they warped that was your machinists fault.
While I'm sure you didn't mean it to sound like you have to have a $150,000 commercially produced piece of equipment to make brass combs the statement
"However metal, particularly brass, presents some challenges that a commercial piece of equipment is perhaps better suited to handle. I don’t own a CNC machine. I don’t know how to write code. Instead, I hired a professional machinist with over 30 years of experience who has at his disposal 17 different milling machines that range in cost from $50,000 to $250,000 each. The one that he uses to cut my stuff is a $150,000 machine. When he is not cutting harmonica parts, he is cutting parts for the military and the airline industry."
kind of makes it sound that way, again, not what a budding comb maker needs to hear. As well as your machinist having 30 years of experience. Let's be honest, about 15 minutes of instruction on how to use the mill and you should be able to make a comb. They are just that simple.
Oh heck no a router isn't comparable to that setup or mine or any other machine designed to machine metal. You're right in that a machine designed to cut metal is always going to be the better choice. But he doesn't have that so I was trying to offer him suggestions that would enable him to get better results.
WD40 is readily available and works well as a cutting fluid on non-ferrous metals, that's why I suggested it. And I know from experience in the machine shop I worked in that a router with the aid of WD40 will work well for what he's trying to do.
When you mention cnc in your post it makes it sound like it's the only way to do it or that the end product is in someway better. Everybody that has made combs in the 6 years I've been doing it has always been eager to throw around the term cnc, heck I'm even guilty of it. What I was trying to point out is that if all he has is a router then more power to him, go for it. Just realize the limitations of what you're working with. But if he wants an accurate well machined comb he's going to have to do it in increments.
Well after re-reading it I did notice the quotation marks, but it seems like everyone in this business is so quick to dissuade people from it by making things sound way more complicated than they are like they are trade secrets.
My point about cnc was to put it in perspective and over the years there has been a lot of BS put out there about cnc and comb making. There really shouldn't be anything about making a comb that's secret, if a person has any experience in working with the tools or materials there's no secret to what we're doing.
Chris
Blowyourbrassoff.com
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Blowyourbrassoff
107 posts
Apr 17, 2014
6:26 PM
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arzajac ,
4 flute for brass, 2 flute for aluminum and wood. But it also partly depends on your setup. Do you have flood coolant on your machine? That will go a long long way to improving performance and quality in the finish.
True about the comb, better materials are going to last longer and be more stable. How many harps have met their doom at the landfill only because they had a bad comb in them? Why not put in a comb that will last as long as the rest of the harp? Regardless of who you get it from.
The airtightness of the comb really only comes into play on a drastic level when you're talking about a harp in the overblow/overdraw category. Putting a flat comb in a leaky harp is probably going to leave you with a leaky harp with a nice comb. Sure it will help some, but chances are, the combs not the real culprit.
You know I actually thought about putting up a video showing how to take a $5 saw and a piece of wood and make a comb, but unfortunately I never got around to it. LOL I had even thought about putting together a kit that came with the wood (probably dymondwood), the saw, some instructions, and putting that out there. But honestly just go to harbor freight and get the saw you'll save yourself some money. LOL
Chris
Blowyourbrassoff.com
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Blowyourbrassoff
108 posts
Apr 17, 2014
6:58 PM
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Depending on how thin an area is I guess it could, but how thin it would have to be I don't know. Chances are though if he's buying his brass in 1 1/2" wide bars the grain is going to be running lengthwise, so it really shouldn't be an issue.
Chris
Blowyourbrassoff.com
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Blowyourbrassoff
109 posts
Apr 17, 2014
7:01 PM
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If he's working on a flat backed comb like a Marine Band the best approach would be to cut the blank to the right length and width with a saw, then when routering out the slots put a support behind the blank so as he pushes in with the router the brace in the back will keep it from flexing. That way all of his force is directed towards the back. I have a feeling it's bowing when he's milling along the back.
Chris
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Blowyourbrassoff
110 posts
Apr 17, 2014
8:50 PM
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WD40 works fine for a cutting fluid on non-ferrous metals. Plus he probably already has some laying around. If he were going to be doing a lot of combs then yeah he could find something better. But it doesn't sound like he's wanting to make that many. So no need to go out and buy a special cutting fluid for it.
Water based coolant is great, for flood coolant, but considering the cost plus shipping I think it would be a waste of money for him to get something like Mobilmet. In fact you can make an equivalent, 1 quart of 10W-30, 4 gallons of water, and just enough dish soap to allow the two to mix. Makes an awesome coolant/cutting fluid.
Chris
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Philosofy
537 posts
Apr 17, 2014
9:38 PM
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I'm really enjoying this thread. I thought about WD-40, but was hesitant because I didn't know if it dripped into my router if that would be a problem. I did try a can of compressed air, but still got the bowing of the brass. I think I have a way to accurately set up a stop for the slot, but I'll have to buy more brass to try it out.
I'm convinced that combs can easily be made with a couple of simple jigs. Brass is the biggest problem because of the warping. I haven't tried wood, Corian, or Acrylic yet. I'm off work tomorrow, and will try to take pictures.
One word of caution for those working in brass: wear gloves! The swarf (sawdust) of brass is like millions of tiny needles just waiting to work their way into your fingers!
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Blowyourbrassoff
111 posts
Apr 17, 2014
10:11 PM
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Yeah if your router is cutting from underneath you might have a problem there. With a router you won't have trouble with the corian or acrylic. It'll just take you a bit of experimenting to work out how fast to move through the material.
The swarf isn't as bad on a regular milling machine, the shavings that come off are bigger and on machines where you have a constant stream of coolant going it keeps them washed away. Watch your eyes though, with a router you're going to be flinging those chips much further than a mill would.
Chris
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JustFuya
71 posts
Apr 18, 2014
7:57 AM
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It's been a while but I had never heard of 1.25 wide flat bar stock so I was curious if it was sheared from a sheet.
You can tell a lot from the curlers and chips your are creating. If I was creating needles, especially from a soft material, I would look into feed and speed. Are the chips brass colored or do they have a burned look? Is the bit sharp?
I've never 'routed' metal so I don't know how much of the tool is exposed. I would use a high level of caution if I got anywhere near a moving part with my gloved hands. And I'll assume you are wearing safely glasses.
Last Edited by JustFuya on Apr 18, 2014 8:40 AM
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harpwrench
827 posts
Apr 18, 2014
10:40 AM
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I'm not trying to be a jackass, because I'm afflicted with the same illness lol, but why are you doing this? One of my wise elders asked me that years ago, and it gave me a different outlook on some projects like this after that.
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www.spiersharmonicas.com
High performance harmonicas.
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STME58
776 posts
Apr 18, 2014
11:08 AM
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@harpwrench, that is a good question.
I have access to CNC mills and enough knowledge to reduce the risk of me getting hurt using them. I was tempted to undertake such a project when I asked myself that question. I really wanted a comb, not the building experience, so I bought one from Blue Moon.
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JustFuya
80 posts
Apr 18, 2014
4:38 PM
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@harpench is right, tho.
If you want a comb that you can use and be proud of, I would start with a flat, parallel piece of metal that is cut slightly oversize. Measure & scribe the lines. Get your hands on a coarse rat tail file and rough the cuts without hitting the lines. Finish to those lines with fine files. Bevel/deburr as required and then finely sand the mating surfaces to flatness. Drill and countersink as required. Sand the flats again.
If you can do that, most metal shops will hire you. With your foot in the door, you will have access to more appropriate equipment and knowledge.
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florida-trader
469 posts
Apr 18, 2014
5:41 PM
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Good idea. Change careers so you can gain access to machines that will enable you to make harmonica combs. Then you can moonlight at a restaurant so you can use their stoves.
Sorry. It's Friday night and I've had a few.
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Tom Halchak
www.BlueMoonHarmonicas.com
Last Edited by florida-trader on Apr 19, 2014 10:45 AM
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harpwrench
828 posts
Apr 18, 2014
6:53 PM
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I'm a dummy when it comes to woodworking equipment, just the way it sounds gives me visions of my hand wrapped in a tshirt and a trip to the hospital lol.
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www.spiersharmonicas.com
High performance harmonicas.
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Philosofy
539 posts
Apr 19, 2014
6:47 PM
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OK, this will be a long post. I tried videoing myself tonight, but that came out horrible. I took some pictures of my setup, but I don't know how to host them online, so I don't know how to show them here.
First, ways to NOT mill a brass comb.
1. On the drill press. I thought I could use what is essentially a pin router setup. I clamp a board to the drill press table, drill a hole with an 11/64" bit, and then drive another 11/64" bit into the hole, letting it sit just proud of the board. This way the bit in the drill press chuck is exactly over the one in the board. I attach a finished comb to the brass blank with double stick tape, and then use the finished comb as a guide on the pin, drilling holes in the blank. But the drill press isn't made to stay steady in the left/right forward/back directions, just up and down. So the drill bits would wander when drilling adjacent holes.
2. On the table saw, using a box joint jig. A box joint jig involves a dado blade (a thick saw blade that is the thickness of the slot you want) and a miter gauge or sled with a 'key'. The key is a piece of wood the same thickness of the slot, and mounted just to the right of the blade on the fence. Its spaced the exact thickness of the tines of the comb from the blade. The problem here is that any error in measurement compounds. So, if the key spacing is off 1/100" on the first slot, its off by 1/10" on the last slot.
I finally found success on the router table. First, I had to buy an 11/64" end mill bit (4 flute, solid carbide.) The shaft of this bit wasn't the standard 1/4" that my router collet took, so I had to also buy a new router collet.
Next, I had to make a jig to hold the brass blank. That was just a piece of 1/8" hardboard for a base (mine was about 12" X 12".) Then I took a 2" strip of plywood and put a 1/4" tall rabbet on the edge. My brass for the harp comb is 1/4" thick. I cut the strip in half, and glued one edge to the edge of the harboard, and the other strip exactly perpendicular to the first strip, like a "T". The rabbets allowed me to mount the brass blank in the jig, and it kept it from being lifted up when milling.
I had an Incra fence on my router table, which allowed me to dial in each distance that I needed, but that isn't really necessary. If you mount an existing comb in the jig, move the jig so the bit is in the slot you want to mill, and then move the fence so it holds the jig and comb snugly, you have the fence adjusted. Tighten the fence, remove the finished comb, and put your blank in. Its ready to mill. Just make sure you mark how deep the slot should be.
The next thing to do is to drill the reed plate and cover plate holes. The jig for that is simple as well. I took a piece of aluminum angle, and glued it onto a thick board. I drilled an 11/64" hole in the aluminum angle, then glued that 11/64" drill bit into that hole. It sticks up about an inch. Now, take your brass comb, slip one of the slots onto the drill bit, and then put a finished comb on top of your brass one. By holding them both firmly against the vertical piece of aluminum, and the drill bit preventing any side to side movement, you can easily drill the holes accurately by using the top comb as a template.
From there I went on to flattening the comb. I start with a coarse file, then a medium file, and move onto sandpaper mounted on plate glass, using water as a lubricant. With brass I start at 80 grit, 120, 220, 400, 600, 800, 2,000 and 4,000 grit (if I recall correctly.) Flattening the combs is a bitch, but when I'm done they have a mirror finish and are very airtight.
As a coup de grace, I have a local trophy shop make me a 1/4" wide 5" long brass sticker with my name and key of the harp.
I know this probably isn't the most helpful without pictures, but let me know if you have any questions.
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JustFuya
84 posts
Apr 19, 2014
7:10 PM
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I'm happy you stuck with it. Your determination is admirable. Sounds like a keeper to me.
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Silvertone
154 posts
Apr 20, 2014
6:54 AM
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Thanks for the description of your process Philosofy.
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