Bike&Harp
99 posts
Jan 08, 2017
1:32 PM
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Bought a low Eb Manji a few weeks ago and i've been taking it apart and slowly tweaking it to my taste. So i noticed that both reed plates definitely look bowed. I thought this was a big no no because of air leakage? So should i send it back and get a new one or straighten them myself. I would probably have to buy Andrew's 'F' tool to do it. However i don't really see why i should have to do it on a brand new harp. Particularly at this price. it wasn't exactly cheap! What would you guys do? Would a shop take a harp back because of that? I don't know if this is an issue on low tuned harps or if i was just unlucky. What i did notice was the reed plates were torqued up to a super tight level and i remember giving up when i went to first take it apart as the screws were so tight. I went back to it later and worked on it. Thoughts guys?
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SuperBee
4405 posts
Jan 08, 2017
3:07 PM
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Bowed front to back, or end to end.
The first is potentially a problem. End to end not usually a big deal.
I've only ever returned one harp and that was due to a bad reed rattle straight from first playing.
But you can do it how you see it. I'm interested to know how Suzuki would respond
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Rontana
362 posts
Jan 08, 2017
5:24 PM
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You might ask Gary Lehmann about this (on the main forum his username in Gnarly). He's a harp tech for Suzuki USA. Email address is gnarlyheman@gmail.com
Suzuki has a year warranty. If the problem is as bad as it sounds, I'd send it off to him. You will probably need a receipt showing proof of purchase from an authorized Suzuki USA dealer
Hope that helps
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Bike&Harp
100 posts
Jan 08, 2017
7:13 PM
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Bee: End to end. Don't see any front to back problem. Sounds fine but i was just wondering. Also what's the deal with the really torqued screws holding the plates on? I thought from watching techs and players that over torquing reed plates is bad as it can warp the plates. I saw that in a video Steve Baker did for Hohner. Whether that also counts for Suzuki i wouldn't know maybe some of the tech guys could comment. I know that whenever i put reed plates on hihner's or seydels and Suzuki's now! i only snug them up i don't over torque them. I won't return it Bee as i love it. Your input put my mind more at rest! Only reason i noticed it really was because it was so noticeable compared to other harps i've got where the plates all look really flat.
Rontana: I'm in the UK mate. Got the harp from 'Harmonica's Direct'. I love the harp but looking at those plates had me wondering as i'm a bit of a tech obsessive! Maybe Gnarly will jump in and give us some input if he see's this.
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SuperBee
4406 posts
Jan 08, 2017
10:35 PM
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Over tightening plates is gonna stress the threads and potentially make the reed plates less flat. You've got a bolt with a head on one side, thread in the other, and as you tighten you are pulling the reed plates closer together. With a solid flat comb I'm not sure how much difference it would make but with a hollow comb like sp20, session, bluesmaster I think it has real potential to make a bad seal where the plates could compress the comb a little.
But in any case, once they are snug they are not gonna get any flatter. I've seen a few harps with stripped threads in reedplates. Seydel seem especially prone to it but it could just be my clients who play seydels. No big deal, just fit a nut, but makes those harps a pill to work on.
Occasionally I get harps with super tight screws. I usually blame the owner but maybe I shouldn't discount the factory workers. I don't imagine the job of assembling harps in a factory is very stimulating and it's possible people just lose concentration or there are new people who don't get the memo, or temporary workers etc.
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MindTheGap
2023 posts
Jan 09, 2017
12:19 AM
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When I was learning about harp maintenance, I was a bit vexed about the whole flatness/airtightness thing.
I noticed some of my reed plates were bowed a bit like you say. A few mm. But when they were lightly screwed down, they seemed fine. I wondered if they were substandard, needed to be fixed, or simply within spec?
Same with the flatness of the comb. How flat did it need to be? The advice seems to veer towards very flat indeed, people talking about buying a sanding surface that is super, super flat. E.g. glass isn't flat enough, you should get a certified-flat steel block (or was it granite, I can't remember).
In engineering generally, things don't have to be perfect to work correctly.
Since I was always being told my stock harps would be leaky by definition, I wanted an objective measure. So I stuck tape over the reeds slots, reassembled the harp, and tried to blow/draw air into the holes. They always seemed very solid to me. I concluded that a slightly bowed reed plate wasn't a problem.
Last Edited by MindTheGap on Jan 09, 2017 12:25 AM
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MindTheGap
2024 posts
Jan 09, 2017
12:29 AM
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One thing I read was that if you emboss the slots to very close tolerances, on a bowed reed plate, when you flatten it by doing up the screws it can change the slot width enough to make the reed stick.
I don't know if that's true, but I remember reading it on the MF. Maybe it was conjecture. I know you are into all that overbend stuff. What do you think Bee?
Last Edited by MindTheGap on Jan 09, 2017 1:08 AM
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Killa_Hertz
2076 posts
Jan 09, 2017
4:33 AM
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In my experience, there aren't many reedplates that are even close to straight. 90% of them are bowed. If your lucky they are a clean arc. Alot of them have a high spot at around the 2/3 hole that leaks in between the slots.
Try andrew zajacs meathod. Draw red marker on the bottom of the plate, then do a light sanding, you will be able to clearly see the high spots.
Manji combs are pretty bad too. You can see the glossy spots that were high. But they sand very easy.
With close inspection you will find out that every harp has degrees of imperfections.
If your plate is bowed and you gapand shape the reeds, when you put the harp back together you will find the gaps have changed.
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SuperBee
4411 posts
Jan 09, 2017
11:48 AM
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I think the dynamic change in the relationship between slot and reed is the real reason to flatten reedplates, much more important than airleaks. Any reed work you've done is rather hit and miss if the shape of the slot changes when you fit it to the comb.
I have a harp herecwhich plays ok on its original comb but 2 draw squeals in a bend if I fit a 'flat' comb. This harp has been worked on by 'a top man at his craft', but there was no comb work done so he has made the slot work with original comb and I suspect a slight warp.
I've never understood the leaky xplanation because any leakage with most combs seems incredibly small but I could see people getting better results from flattening combs and reedplates so there is clearly something in it. The slot/reed interaction seems likely to me
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Killa_Hertz
2077 posts
Jan 09, 2017
2:53 PM
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Your right Bee. It is incredibly small. But you well know how small changes can effect playing.
For instance, sometimes the gaps of the reeds in a certain slot will look good, but for some reason it just isn't playing quite right. Then you tweak one ever so slightly and Boom .. now its money.
This happens to me sometimes on the 3 draw reeds.
Im finding the better my playing gets, the less sensitive I am to these small changes, but they used to drive me nuts.
If you have the patients to get a comb and plates TRULY flat .... it makes quite a difference. I have a marine band that i made that just plays phenomenal.
But it took me forever. So i just get mine pretty good now ... i don't really chase the perfect harp anymore, it's too tiresome.
I think you do have a point there bee. But i think you will find the airloss alot of times is between chambers. And it will feel as if your losing air. Like a gap thats open a tad too much. Again, i think the better i get the more i don't notice it. But if you fix it you ll notice how much you were losing.
When you get your harp truly tight and the slots set right ... it's like the harp is ultra responsive.
Last Edited by Killa_Hertz on Jan 09, 2017 2:56 PM
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SuperBee
4413 posts
Jan 09, 2017
8:31 PM
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ive always had doubts about the importance of the 'air-tightness' angle. i mean, its obvious that less airgap should make a more responsive unit, but 'how much?' difference does it make to sand a draw plate, i wondered. i can see almost every marine band draw plate has a dimple at the rivet end of holes 1 and 2, and again there appears to be some distortion around slots 9 and 10 on almost every harp. you can sand those plates so they are evenly shiny and put them on a flat comb and no doubt they are better but does it make an appreciable difference?
one reason to sand a draw plate is that you have done work on the comb and sanded out the divots which used to relieve the protruding rivet ends. or you are fitting a solid comb which has no reliefs. so you sand the plate to flatten those rivet bumps. in the process you flatten out some of those distortions in the plate.
another reason to address reed plate flatness, especially front to back flatness is because of the effect on the reed/slot relationship. at the same time you might be making the plate sit better against the comb, but the reason this is an issue in the first place is because of the tendency of the reed plate to flatten when it is fastened against the comb.
of course sometimes you remove a reedplate from the comb and you can see the watermarks on the brass and on the comb and its clear there has been penetration, but again there is a mitigating factor, as over time this penetration will tend to seal up the leaks. some folks used to add some sort of goo, like chapstick, to hasten the process. i don't know if it helps or hinders really.
really flattening a reed-plate, beyond just sanding off the bumps, is a mystery to me. you can try to do it with AZ's F-Tool. i guess that works. seems to me it has potential to create a very bumpy wavy reed-plate too, but i've used it. i don't think i can see this as a pro solution. it seems quite inefficient. there must be a better way. you'll see that none of the customisers really talk about how they flatten reed plates or centre reeds in slots
its interesting to me that richard sleigh is now turning out harps 'with high quality reed and slot work' and no work on the combs at all. stock combs, no reed plate flattening, just reed and slot work. according to richard this is where the bang for buck is.
it may be worth noting he is not a comb manufacturer.
It may also be worth noting he only does marine band deluxe and crossover harps like this.
it may also be worth noting he will not say how he centres reeds except insofar that he has a 'big-ass' piece of equipment about which he is sworn to secrecy.
also recently noted (not for the first time) Andrew Z citing the retention of nailed reedplates in 'fully custom' marine band. ive known him to previously talk about the capacity of the nails to provide a better fit of plates to comb in these harps in some circumstances, than the changeover to screw fasteners. This is one of the reasons i have retained original combs with nails in some of my marine band harps. i felt the response of some of them was so good i didnt want to mess with something that worked so well. I have gig-standard F, Eb, Bb and Ab marine band harps on original nailed combs. 7 nails in each plate plus the pressure of the covers at each end must go a fair way toward sealing up these harps. when i see 'leaky' used in connection with a new marine band, i assume a gapping issue.
and this really is where my doubt about reedplate flatness as a major factor in harp response began. i realised that every harp has 2 big holes in each chamber regardless of how tightly the plates conform to the comb. when i inhale through a chamber in the harp, there is a reed on the bottom being drawn into a slot and sure that slot may be carefully sized and the reed offset minimized to provide a very sensitive reed, but there is still a hole in the top plate with a reed which wants to move inwards, making the hole above more open to the chamber as i inhale. how significant can a small crack between comb and plate be, compared to that?
i honestly don't know. people tell me its significant, (and at least one of the guys who peddles that line very heavily happens to also manufacture after-market combs)but then i see a guy like Richard Sleigh just not even bothering with it and it makes me wonder.
Now richard might be skilled enough with reedwork to be able to get good response from a reed in a bowed plate but i think i need a flat plate and slot. anyway this is why i think maybe the best reason for addressing reed plate flatness is so that you can get your reed work more easily sorted
Last Edited by SuperBee on Jan 09, 2017 8:42 PM
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Killa_Hertz
2078 posts
Jan 09, 2017
8:43 PM
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Very nice. You make alot of good points. It seems to make a difference to me, but i have done no scientific experiments to prove this. It very well could all be bogus. Who knows?
What you have said here does make alot of sense.
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SuperBee
4414 posts
Jan 09, 2017
8:57 PM
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ha, thats the fun of it. lots of us don't really know but we follow our lines of thought and take advice from those we think might know, and who knows what they really know because (i think)they really aren't telling the important stuff. I look at my Spiers harps and i can see the signs of a bunch of stuff but i know i'm only guessing at how and why.
so you follow your musing and make a few experiments and maybe you learn something. maybe you learn you really got no idea (thats me a lot!)
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MindTheGap
2025 posts
Jan 09, 2017
11:53 PM
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SuperBee - that squares with my line of thinking.
From a physics point of view, there's different kind of 'leaks'. When there is a flow going on you don't need a hermitic seal in order to provide a seal that's good enough. All you many need is a flow path that's resistive enough. It seems very likely to me that the resistance of the reed-plate-to-comb seal ought to be much higher than around the reeds - just as you say.
In that case, once the reed-plate-comb seal was beyond a certain quality, you'd experience no further improvement until you improved the reed-slot seal.
When I first started on MBH, I read and was told directly that flat-sanding on any OOTB harp (not just one that was wrong) would give a night-and-day improvement. So I tried it and it didn't. It could be I didn't do it properly, but even so if there was massive improvement to be had, I'd expect to experience some change at least.
As I said, a direct measure i.e. taping over the reeds/slots in a hole and blowing/drawing indicated the seal was good. I can't understand why customisers like Andrew Z don't suggest that. Maybe they do and I've missed it.
Last Edited by MindTheGap on Jan 10, 2017 12:06 AM
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MindTheGap
2026 posts
Jan 10, 2017
12:01 AM
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Re the bowing, I can see that a small bow in the direction Bike&Harp has seen i.e. end to end, one which unrolls nicely when the reed-plate screws are applied, could be desirable. And preferable to a potentially flatter, but wavy, pattern that you might induce by locally flattening it.
I wonder where the bow come from in the first place? Is it from the original blank plate material e.g. stored in a large roll? Or as result of stamping out the slots? Or riveting/welding?
Interesting that the ones I've seen always have had that end-to-end bow rising up at the ends. Could it be they take that into account in manufacture? Maybe a question for Tom Blue Moon.
Last Edited by MindTheGap on Jan 10, 2017 1:33 AM
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MindTheGap
2027 posts
Jan 10, 2017
12:21 AM
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...just to say as with all the musings, I'm more than happy to be proved wrong, but it's better to be shown than told.
Last Edited by MindTheGap on Jan 10, 2017 1:32 AM
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Bike&Harp
103 posts
Jan 10, 2017
9:00 AM
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Great posts guys and all very interesting points. Another thing reed/slot related but going off on a slight tangent is viewing the reed and slot. When looking at the clearance for the reed i sight it to a bright light and then pull it slightly off the light as that seems to give me the best view of what's happening. But the crux of what i'm talking about here is your head position when you're viewing the reed/slot tolerance. If you're not consistent in head/eye position then you don't get the proper feedback as to what's happening. I'm sure Richard Sleigh did a video on this where he developed a system which ensured he was always viewing each reed from the same point ensuring he was getting consistent feedback. It's so easy to look at a reed from a slightly skewed angle and then make wrong assumptions as to what work needs to be done to improve things.
Also this might seem a dumb question but i'm going to ask anyway! Do you sight with both eyes or with one eye and the other shut when you're looking at things closely? I do it with both eyes as when i look with only one eye it seems to completely change the picture as to what's going on.
People think harps are simple but they're really not. Simple on the surface yes but there's a lot of tight tolerances and things at work.
** Incidentally i received Andrew's reed removal tools today and have to say i'm very impressed with the quality of the service and the tools. So a big shout out to Andrew for that. His service all the way from Canada to the UK was outstanding. These are the guys we should all be supporting.
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SuperBee
4417 posts
Jan 10, 2017
11:56 AM
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In the land of the blind, the one-eyed man is king.
I'm grateful to have one eye I can use for this kind of work. Not as good as it used to be but still ok.
Yes, sighting position is important. Stay aware of the issue.
Light is very important.
Richard did make a video on topic.
I do think Andrew is an honest operator who is genuinely trying to be helpful while making some income. And I do support those efforts as do many others.
There are others who are less forthcoming but also may have deeper insight into some things.
There is competition as well as collaboration. Is there deception? I'd go so far as to say 'perhaps'. There are certainly some relationships which affect how much people are prepared to say
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JustFuya
1035 posts
Jan 13, 2017
6:15 AM
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MTG - I believe that all the causes you mentioned have an effect on plate warp: heat and stress. The reason they tend to warp along the length is simply because it's the path of least resistance. At the low end of the reed plate there are smaller tabs of metal between the reed holes and these are more susceptible to manufacturing stress, whether it's heat from lasering/welding or stress from punching.
I also noticed extreme bow on Suzuki reed plates. I think they over-torque them during assembly to compensate. I'm amazed that those tapped holes can withstand this torque without pulling threads. I bet they are holding a closer tolerance on a finer thread than Hohner uses. I doubt that a Hohner reed plate would hold up to the same torque.
You gotta respect customisers who work on harps made by multiple manufacturers. Each one has to be handled differently. For example, Suzuki reeds dive into the slot at the spotweld end while Hohner reeds pooch up as the enter the slot at the rivet end.
[I'm visiting this beginner thread for the first time. Much more interesting material here than elsewhere lately.]
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