Harmonica cover plates

[swarfmacdaddy]

Can someone please tell me what would be the most cost effective way to make my own harmonica coverplates? The metal is 0.025 thick. I have been to several machine shops and they have been no help. They all say Im going to need 10's of thousands of dollars. Could this be done in 1 shot or do I need a set of progressive dies? Can I make the original from plaster or something then have it cast? I have read tons on the net but am still at a loss. And please! Dont say out source to China. Here is a pic of some custom harmonicas I make. Dont know if this is the right forum or not. THANKS!

[RotarySMP]

One way of making making a few would be to use electroplating to build up the required thickness over a mold. This can be done quite cheaply with copper, and then have it chromed.

[swarfmacdaddy]

Where would I research this further? I actually want to make many thousands of these. Thanks

[Jim Estes]

Are you just wanting the top and bottom cover piece? Are the edges rolled, with a folded bead? Why not post an RFQ on RFQ.com and see what you get.

Jim

[swarfmacdaddy]

Just the front edge thats open is rolled. The rest must be cut and dead flat.
I would rather do them myself if possible.

[swarfmacdaddy]

Sorry, I forgot to say I just need the covers . I make the combs (body) myself.

[Jim Estes]

Would you happen to have any drawings of the covers? It would help to see all the details.

Jim

[swarfmacdaddy]

No, not just yet. But they are pretty close to the ones in the picture. The front will be more open for better sound projection. And the side with the holes will have a narrower profile.

[Wiseco]

You should check to have a mold build but not a mass production one. Check with Protomold, they make alum mold for applications like yours for not too expensive.

[Jim Estes]

swarfmacdaddy,

I drew up a quick drawing of the top of the harmonica I have in my desk. I made an BMP of it so you can see what is in the file. If this is what you are looking for, the file might help.

Jim

[swarfmacdaddy]

Thanks for the reply Jim. Here is a better picture of what Im trying to do. In the first pic on the left I want a profile like the blue and green harp but more of a gradual slope up. But still very open in the front. I would like to have the short ends like the harps in the right pic. You can see more of my harps at genesisharmonicas.net. Im making these myself now but Im using other manufacturers covers. I want my own covers to make the harp totally mine.
Thanks for your help, Randy

[One of Many]

Originally Posted by swarfmacdaddy Thanks for the reply Jim. Here is a better picture of what Im trying to do. In the first pic on the left I want a profile like the blue and green harp but more of a gradual slope up. But still very open in the front. I would like to have the short ends like the harps in the right pic. You can see more of my harps at genesisharmonicas.net. Im making these myself now but Im using other manufacturers covers. I want my own covers to make the harp totally mine. Thanks for your help, Randy

Randy,

From what I can see of the shell, these are done in multiple steps. That doesn't necessarily mean they were done on a progressive die, but it would be the most productive.

Most of these I have seen are chrome plated steel or brass. A few of the high end ones are stainless or high nickel and even silver. My Father had a few old ones and liked to hear them but never really played himself. I just as well admired them as works of artistic craftsmanship, rather than try and play one.

In terms of the obvious for working metal. At minimum, you will need a hardened steel form profile of your covers, in order to hand work brass or copper sheet, although hard wood works for soft materials. This may involve several steps to anneal the material after it work hardens from cold working it into shape. Then send them out for chrome or nickel plating after polishing to a mirror finish.


For high production. I am guessing you will need a punch press capable of around 40-60 ton capacity. You could make separate dies for punching the blanks and then forming them to shape, then another for trimming and punching mount holes after forming. Then another for the logo, unless you could incorporate that into the forming die or custom engrave it somewhere in the process. Just the tooling itself is truly going to be a huge investment. How much you can do yourself will be a large factor in the end cost. Maintenance on the dies to keep them in top shape requires support equipment too.

What about chrome finished or colored vacuum formed plastics? If anything else, this will get you your own unique shape proven with cheap materials and tooling in the short term with your eye on the horizon to the real goal.

A couple other ideas to consider although would require secondary trimming, which might be a challenge in itself. Hydro-forming or Rubber forming to move the material into or over a die of the desired shape, then trim as required. I've seen some pretty amazing small volume forming done with a couple of oil ported heavy steel plates bolted together(one being the die cavity), sandwiching a seal and sheet to be formed on the cheap. Provided you have a port-a-power pump capable of 10,000 psi. Messy and slow loading and unloading the sheet with all the bolts holding it all together, but it worked.

DC