Jigs or fixtures for engraving banjo hoops, etc.

[mgdesigns]

Does anyone know what types of fixtures or jigs could be made to allow accurate engraving under a microscope of banjo tone rings & hoops? I've done a few parts so far but need to know if someone who has done many has ideas or photos of their setups.

The other parts I've done (armrests, and covers for tailpieces) are really not difficult to clamp up, but the bigger ones may be a bit cumbersome.

Thanks ahead of time for the help. This forum has already proven very helpful, and thank you Sam & Abigail for the great place to meet and share knowledge.

 

[Tim Wells]

I've been thinking about this off and on since last week and how one would approach the problem of holding a tone ring.

If it were me I'd make some sort of way to put an axle in the center of the ring to rotate it like a wheel. That means you'd have to make a spoke arrangement to hold the ring firmly without stretching it or warping it and at the same time hold a bearing so it could be mounted on a shaft held in a vise. THe whole arrangement would need to be stiff enough so as not to let the piece bounce.

If you can do that and arrange it to where just the part you are engraving was at the top of the arc in focus under the scope you could cut all the way around the thing non stop by just rotating the ring. I don't plan to engrave any of these but I like to work the puzzle anyway and if I were to do one, I'd take the time to make a holding tool to do a hundred of them. I'll give it more thought and draw something later and scan it in here.

 

[pilkguns]

Mark, Given the size and style of banjo type engraving, and who I think you are engraving for, I think you are kidding yourself trying to use a microscope. If any magnification is required, a #3 or #5 optivisor would do the trick plenty good.

It's funny Tim is replying to this thread to, since he was the one you were supposed to meet here that time your truck had problems. You gonna be here June 11th?

 

[mgdesigns]

Scott:

"Mark, Given the size and style of banjo type engraving, and who I think you are engraving for, I think you are kidding yourself trying to use a microscope. If any magnification is required, a #3 or #5 optivisor would do the trick plenty good."

I'm probably a lot older and blinder than you. I use an optivisor #5 just about all day at the jeweler's bench, but when I engrave I've become accustomed to that detailed view. May be a bit of overkill, but I like the control it affords me. But I may try to use a visor.

Re: Post-BLADE-Get-together:
I am trying to block that weekend out in my work schedule, so I can attend the BLADE show. New job, new employer - not sure. But, I'd love to come up and meet everyone.

Tim - great idea. I like the idea of a bearing loaded axle to pivot on. Being that these tone rings and hoops are about the same diameters, 2 - 1" thick semi-circles with a gap of about 1" between them, a sleeve bearing pressed into one side, with all-thread adjusters to stretch out and clamp the parts to be engraved may be the trick. I'll sketch up and post. DONE. What-ya think? No nuts shown on alltreads (blue cylinders). According to Stewart-Macdonald parts house, the hoops and tone rings are available in 2 sizes (11" & 12" diameter). I'd need to verify the bore diameters, and contours, and possibly cover the external faces of clamps with nice leather. Then make a couple of gudgeons for the trunnion (shaft-thru-bearing) to rest on, and a screw to hold down. If i do enough of these the fixtures would surely pay off in time saved handling.

 

[Jim-Iowa]

In my meandering mind I can't help but wonder if a pneumatic drum like is used for the flexible sanding drums might be the ticket? Just slide the ring on take a couple pumps with a ball pump to tighten and then pivot on the spindle?

 

[pilkguns]

Scott:



I'm probably a lot older and blinder than you. I use an optivisor #5 just about all day at the jeweler's bench, but when I engrave I've become accustomed to that detailed view. May be a bit of overkill, but I like the control it affords me. But I may try to use a visor.

To my way of thinking, I think there is far more benefit to be gained by doing all my jewelry work under the scope, and all my banjo engraving under the optivisor. As big as the banjo patterns are , you will be out of the microscope's feild of view immediately, really there is no practical way to cut large wiggle patterns under a scope, and really the styles of wiggle and bright cut used on musical instruments do not require any of the amount of precision that a microscope gives you.

 

[Tim Wells]

Scott, as long as you got chickens left I'll be up thata way come June... With my bib on.

 

[Ray Cover]

Bib?... Dang Tim you are refined

Ray

 

[Tim Wells]

You got that right. It doubles as the front of my overalls, I just open that zipper falp at the top and save what falls in it for later.