apskarp
572 posts
Dec 27, 2011
11:10 PM
|
I'm an engineer. So this mean I rarely read any manuals for anything but rather trust that I can do it without. This has some side-effects.
The other day I found finally time to change dymonwood comb for my Eb MB. I usually use SP20's so I haven't had a case with setting up the screws for nail plates.
I thought it is pretty easy job to do. I took my dremel tool and widened the nail holes enough so that I could make the screws fit it and use those screws to actually make the screw threads. Then I widened the other plates holes so that the screw goes easily through.
You guess what happened?
Of course the nail holes were on different places! And my luck was that I made the screw threads to the wrong plate - ie. the one that has them on the wrong place compared to where the holes are on the comb... Arrgh!
Fortunately the nails still fit the plates so I just changed my approach and flatsanded, rounded and sealed the original comb. So this Eb will have a fully sealed original comb after all.
Next I will try to do the comb swapping again for my fully sealed F-harp. Any tips of how to do this without unnecessary pain? I'm thinking of making the screw threads to the right side now and then drilling the holes to the other plate on the same spot. Perhaps I'll keep the plates attached to the original comb first so that I can use those (right) nail holes to guide the drill bit...
----------
Hoodoo Sauna
|
HarveyHarp
338 posts
Dec 28, 2011
8:52 AM
|
A lot of the mechanics of changing nails to screws depends on how you choose to place the holes. Personally I use the right two holes on the blow plate, and the left on the draw plate.
If you want to leave the geometry of the comb and plates the same, then you can do this as you are taking the nails out, if you know what I mean. If you wandt to round everything nicely, and make a custom looking harp, like I do with my customes, then I drill the cover plate holes out, and bolt the harp together that way, mount the reeplates flush with the front of the comb, drill my reed plate holes, fasten the whole thing together, and then sand the whole assembly on a belt sander. Of course, that way there is only one comb that will fit you reedplates.
Hope that makes sense.
----------
HarveyHarp
|
oldwailer
1807 posts
Dec 28, 2011
9:40 AM
|
I had a request once to make a comb for an MB--and I think you can buy combs for them online--what I don't get on this is how a new comb could have the holes in the right places.
I do a nail replacement like HarveyHarp says above--when I change the comb (which I almost always do), I just drill the holes through the old comb and both plates--using a bit that is sized to take a 2-56 tap. Then, when the harp is disassembled, I enlarge the holes that need it with a slightly larger bit and tap the others. then I can just clamp one of the plates to the new comb and mark the holes on the comb--and drill them a size bigger.
Before I take anything apart, I think it's easier to drill holes through the whole harp, coverplates and all, where you will want to put the coverplate screws--sometimes the nails on the coverplates won't line up perfectly to use those holes as markers.
Done carefully, this method assures that all holes will line up perfectly, since they are all drilled at the same time. . .
----------
Oldwailer's Web Site
Always be yourself--unless you suck. . .
-Joss Whedon
Last Edited by on Dec 28, 2011 9:41 AM
|
Baker
189 posts
Dec 28, 2011
9:45 AM
|
My process is based on these instructional videos:.
http://www.youtube.com/watch?v=h_9mMUAt3yY
I attach both the plates to the new comb and drill down from top (blow) plate to the bottom (draw) plate with a small drill bit, smaller than the screws diameter so you can tap the threads with the screws.
Then I remove the draw plates and clean up the new holes with a file.
With the blow plate still attached to the comb I widen the holes with a slightly larger drill bit. Enough that I can push the screws through but not too loose. I then remove the blow plates and clean these up with a file making sure everything is flat with the comb.
I then attach both plates back onto the comb, push the screws through and tap them into the draw plates.
The important thing is to make sure that when the plates are attached to the comb they can't move while drilling or tapping, this will ensure everything lines up properly. There are different ways of doing this, you could clamp them, or use double sided tape. I fix the plates in place by nailing them to the new comb using the old nails.
I hope this makes sense and is some help.
EDIT: Oldwailer posted while I was writing. The trick as he says, is to drill through the whole harmonica with everything fixed in place. This ensures everything is lined up properly.
Last Edited by on Dec 28, 2011 9:48 AM
|
apskarp
573 posts
Dec 28, 2011
1:12 PM
|
Thank's for the advice. For me it seems that the draw plate (or was it the blow?) has the nail holes in exactly the right place when comparing to the dymonwood combs I have. (Got them from Buddha.) I suppose the holes in the comb are in the standard place. Perhaps the same place as in MB DeLuxe?
So in principle you could just make sure that the new comb has the holes at the same place as the nail holes and then just remove those nails and drill the holes to the plates without even removing those from the old comb. This operation you could do with the same steps as Baker here described - the only difference is that you don't attach the plates to the new comb but leave them on the old one.
Richard Sleigh had some advertisement where he mentioned that his method of swapping the combs is suited to MB 1896 if the plates have date stamped to them. I don't know but I suppose that those plates have the nail holes in that standard place...?
----------
Hoodoo Sauna
|
florida-trader
77 posts
Dec 28, 2011
1:40 PM
|
Apskarp. In the event that the pre-drilled holes on the comb don't line up with the nail holes on the reed plates, the question becomes, "Do you drill holes in the comb to accommodate the reed plates, or do you drill holes in the reed plates to accommodate the pre-drilled holes in the comb?" I vote for the latter. Drill holes in the reed plates. Why? If you start drilling more holes in the comb you will likely create some little burrs from the bit poking through the opposite side where the bit entered. Then you have to flat sand the comb again. It's an extra step you can avoid by not drilling the comb. The brass reed plates are a snap to drill through so the old nail holes don't give you all that much of an advantage. What's the big deal? So you have a couple of little tiny nail holes. so what. Whether you use the three top nail holes or the four bottom holes or two and two as Harvey says, you're still going to have some unused nail holes. If you are trying to build a "one size fits all" comb that's one thing. But if you are drilling one comb for one set of reed plates, it doesn't matter at all where you drill the holes, as long as you accomplish your mission - which is getting a good seal between the reed plates and comb.
----------
  ">
|
apskarp
574 posts
Dec 28, 2011
9:26 PM
|
I hear you florida-trader. The point is that I have a set of custom-made combs. So as you said I'm not interested to drill more holes to them. However, for me it seems that the nail holes on the other reedplate are already in the same place as the holes in the comb. So the only need is to drill holes to the other reedplate.
As a working process this would mean that it is best to leave the reedplates attached to the old comb while drilling - that way you make sure the holes will match perfectly. The existing nail holes will work as a guide for the drill bit.
Do you agree?
----------
Hoodoo Sauna
|
florida-trader
80 posts
Dec 29, 2011
9:10 AM
|
I agree IF the pre-drilled holes on the comb match up with the nail holes on the reed plates. Then it makes perfect sense to drill the holes in the reed plates while still nailed to the stock comb. You are basically using the factory built assembly as a jig.
That said, here's the rub - and I do not mean to be contrary. Hohner has been making Marine Bands for over 100 years. If you read Pat Missin's excellent piece on how the MB has changed over the years (found here: http://www.patmissin.com/ffaq/q38.html) or Richard Sleigh's Marine Band Guide, you quickly realize that there have been a lot of subtle changes that have taken place in the design over the years. When somebody orders a MB 1896 comb from me, I have no idea when his MB was made. Even if I did, I would not really and truly know what the differences would be in different model years. I just know that there are some differences which can create a situation where the pre-drilled holes on the comb don't line up with the nail holes. In short, it should come as no surprise that with Hohner manufacturing millions of Marine Bands every year, decade after decade, that there would be some degree of variance. The point is, make sure the holes on the comb do line up with the nail holes before you start drilling or else you might find that you drilled holes in the wrong places.
By the way, this is precisely why a lot of the guys like un-drilled Marine Band combs. They want to put the holes where THEY want them and not where somebody else thinks they should be.
----------
">
|
apskarp
576 posts
Dec 29, 2011
10:08 PM
|
Fortunately it is really easy to see if the nail holes match in just a few seconds. If they don't you can just make marks to the right spots and still drill the holes with the old comb attached.
I suppose Richard Sleigh's directions for comb switching are made to these newer MB's where there is date stamp om the plates.
----------
Hoodoo Sauna
|
