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Author Topic: Surface grinding?  (Read 18114 times)

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Re: Surface grinding?
« Reply #10 on: May 15, 2008, 12:53:10 PM »
I've tried 34 shops that "specialized" in CNC equipment and had CNC SG. Most said the couldn't do my stuff after I'd sent them the specs/drawings. 4 tried and gave up after a few rounds. 1 guaranteed that they could do it if I invested $20,000 to alter their machine. The last one was able to make the parts but I had to wait a month between trials and I just can't have that sort of delay.

All the people I know that make these reeds have their own machines, and those machines have been customized to make only reeds. Sounds like I should give up on the .0002" tolerance. If I do that means that I'll be hand finish profiling about 15% of our work. Not fun when we'll be going through thousands of reeds.

I was thinking that for those persnickety 15% I would work our some way of measuring them prior to doing the final passess in order to make adjustments for tolerances?

-- Rich --

vmax549

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Re: Surface grinding?
« Reply #11 on: May 15, 2008, 01:12:36 PM »
You need to find a shop that specializes in CNC grinding at the micron level. BIG difference(;-) and it will not come cheap.

BUT that is not to say it cannot be done in house. You will however have to start with a high end low tolerance grinder and retrofit from there with a controller that can WORK in those tolerance ranges and have fluid movement at that resolution.

Do you have a print of an example part???

(;-) TP
Re: Surface grinding?
« Reply #12 on: May 15, 2008, 01:41:50 PM »
Here's a print of 4 of the several dozen profiles we'll be needing. These are an octave apart and you can imagine what the profiles in between would look like and the ones an octave beyond in both ways.
http://home.comcast.net/~r-morse/BBox/images/reeds-e-a.gif

Here's a photo of those 4 reeds.
http://home.comcast.net/~r-morse/BBox/images/new-reeds.jpg

-- Rich --
Re: Surface grinding?
« Reply #13 on: May 15, 2008, 03:07:18 PM »
I suggested he consider sinker edm. Too easy to burn/warp stock this thin.
"If you tell a lie big enough and keep repeating it, people will eventually come to believe it." - Joseph Goebels
Re: Surface grinding?
« Reply #14 on: May 15, 2008, 03:25:35 PM »
Yup.... we tried EDM. This was the most successful trial. All the others cut through as the material broke free from the magchuck.

-- Rich --
Re: Surface grinding?
« Reply #15 on: May 15, 2008, 04:49:30 PM »
Well I'm glad I'm not making them.

I think we can safely say that if a professional cnc grinder cannot do the job them a home built machine is out of the question.

Have you thought of wire EDM ?

Maybe forming them on a press "Would Be A Lot Quicker" then grind to width.

HTH
Phil_H
The Good Thing About Mach3, Is It's very Configurable

The Bad Thing About Mach3, Is It's Too Configurable
Re: Surface grinding?
« Reply #16 on: May 15, 2008, 04:56:20 PM »
Have you thought of wire EDM ?
The photo above is a wire EDM job.
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Maybe forming them on a press "Would Be A Lot Quicker" then grind to width.
I didn't know you can press spring steel into a profile??? Does it change the temper or density? Probably very expensive if you'd need to make a diferent form for each of the shapes (profiles) we need?

I was wondering about grinding them apart (to width). I figure I'd give that a try before sending it out to be wire EDM'd apart.

-- Rich --
Re: Surface grinding?
« Reply #17 on: May 15, 2008, 05:44:45 PM »
Rich,

It would be in the realms of possibility to make your own press tool by CNC SG forget the reeds.

Its initial cost will be repaid in speed of manufacture of parts.

Virtually all springs are made by forming of one sort or another.

I have even made my own springs "Coil Compression" on a lathe with no CNC when i was an apprentice. Hell CNC wasn't even invented then.

As to their tonal quality after stamping, i don't know you would need to speak to a metallurgist.

But there are various heat treatments that maybe could help tonal quality.

More trial and error as always.

Phil_H
The Good Thing About Mach3, Is It's very Configurable

The Bad Thing About Mach3, Is It's Too Configurable
Re: Surface grinding?
« Reply #18 on: May 15, 2008, 05:51:56 PM »
Hate to be a killer of joy but you asked for additional info. That machine is not right for the quantities and what you want to do. It's your money and do as you wish.
I wish that people will tell me what I'm doing wrong and what I should be doing - and so far I'm pleased with all the advice I'm getting. Advice is cheap - buying the wrong machine expensive (and stupid!).
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You need to grind wet to avoid heat.
I realize that. The Syil guys say that those photos don't show the proper coolant system that you can get with the machine. I'm also figuring that we'll need a custom chuck, splashguards, auto-dresser, etc....
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No, ain't no deisgner of reeds by any means, but my father's music major instrument was the accordian. He repaired them, and hand made reads...
Sounds like you've got a good handle on what we're up against.
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Now if a pro shop can't rationalize out making money on your item or knows  proper investment to meet your criteria what makes you think your going to do it for a fraction of cost and with an infearier machine.
"Pro" shops can't seem to make reeds at any price - period. We're not looking to make reeds at a fraction of the cost than we can get them from the Italians or Czech... we would gladly buy them if they cost 5 times as much as accordion reeds - but we don't want accordion reeds, we want concertina reeds - but no one makes concertina reeds for sale... so if we can't find someone to make them for us... we have to make them ourselves.
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Have you ever considered changing the design of the reed?
Yes, but there's not much one can do before they're no longer concertina reeds.

-- Rich --


 



Re: Surface grinding?
« Reply #19 on: May 15, 2008, 05:56:30 PM »
It would be in the realms of possibility to make your own press tool by CNC SG forget the reeds.
I'm not sure what you mean by that. What's a press tool? Can it squish spring steel into these profiles: http://home.comcast.net/~r-morse/BBox/images/reeds-e-a.gif

-- Rich --