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Spinning radish dishes
http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10101&t=55191		 Page 1 of 2
Author:  Pegasusguitars [ Sat Aug 13, 2022 2:14 pm ]
Post subject:  Spinning radish dishes
For years I have used my drill press to drive radius dishes. Works pretty good for smaller instruments like ukes,and works, but is awkward for guitars. I'd like to make a more user friendly, motorized, dedicated dish spinner. I have a 3/4 H.P. DC variable speed motor available. The main issue is how to attach a variety of dishes directly to a vertical motor shaft. Looking for ideas. Much appreciated,,Bob
Author:  doncaparker [ Sat Aug 13, 2022 4:05 pm ]
Post subject:  Re: Spinning radish dishes
Here is mine, Bob:

viewtopic.php?f=10101&t=51545&hilit=Motorized+dish
Author:  Clay S. [ Sat Aug 13, 2022 4:19 pm ]
Post subject:  Re: Spinning radish dishes
Hi Bob,
Visions of a tossed salad! It looks like spell check struck again!
If you can drill through the motor shaft and install a pin you could use a pipe flange and short length of pipe with slots cut in it to do something similar to how the Bosch mixer/sander attaches dishes.
Author:  Pegasusguitars [ Sat Aug 13, 2022 4:58 pm ]
Post subject:  Re: Spinning radish dishes
Clay- You always have rather, how should I say it, unique ideas! What is that thing?-Bob
Author:  Pegasusguitars [ Sat Aug 13, 2022 5:24 pm ]
Post subject:  Re: Spinning radish dishes
Thanks to whoever made this old thread re-appear. Since I plan to use my variable speed motor, all I really need is a way to attach the dishes to a verticle 5/8" shaft, hopefully without the need of a jackshaft.. Don was lucky to have found that used disc sander plate. That would be an easy solution. I have always run my dishes sitting flat on a waxed formica base, and that works great. Very little friction. Dishes are centered on a 1/4" brass pin that runs in a 1/4' brass bushing. Cheap, ad never wears out. Because these flakey fiberboard dishes we use never stay flat, there is some wobble to them, but it really does not seem to affect anything. -Bob
Author:  Clay S. [ Sat Aug 13, 2022 9:04 pm ]
Post subject:  Re: Spinning radish dishes
Hi Bob,
That unit is a mixer/blender my brother brought back from Germany. His wife found it less useful because it runs on 220V and needs a stepdown transformer or 220V outlet and plug adapter. The "beaters" mount to the shaft sticking out of the bowl and I screwed a disc to the beater attachment and removed the beaters. The attachment slips on and off the shaft and over the pin which keeps them from slipping. I have another attachment so I can mount a different disc as desired. A similar mounting system can be made by using a pipe flange, a short length of pipe and cutting slots in it that would slip over the shaft of the vertically mounted motor. The Bosch has 3 speeds. Since the DC motor is variable speed you should be able to adjust the RPMs to suit the work.
Author:  Clay S. [ Sat Aug 13, 2022 9:37 pm ]
Post subject:  Re: Spinning radish dishes
A rough sketch of what you could do with pipe fittings:
Author:  Clay S. [ Sun Aug 14, 2022 7:46 am ]
Post subject:  Re: Spinning radish dishes
One thing to keep in mind considering the weight of the typical dish and the fact that most electric motors are not designed to support great axial loads on their shafts - some way to support the weight of the dish independent of the motor may be prudent. Supporting the dish on the waxed Formica base with a cut out for the flange and pipe to pass through should work fine. The motor could be mounted so the pins in the shaft don't "bottom out" on the slots in the pipe to eliminate any axial load that could be created by the weight of the dish.
Author:  doncaparker [ Mon Aug 15, 2022 7:53 am ]
Post subject:  Re: Spinning radish dishes
Could you make a drive plate out of something like this, Bob?

https://www.ebay.com/itm/282690731740?h ... Swyi9aAePX
Author:  Clay S. [ Mon Aug 15, 2022 9:41 am ]
Post subject:  Re: Spinning radish dishes
Hi Don,
The pipe flanges might be a more economical option. Apparently they are marketing them as decorator items these days. [headinwall] They should be available at the local big box stores. In combination with a pipe nipple and a hack saw a person could make multiple fittings that would drop over the pin drilled through the motor shaft, which would allow the dish to be quickly changed out.
https://www.homedepot.com/p/PIPE-DECOR- ... /318268488

I looked at the eBay item you posted. It uses a "key" to keep the plate rotating with the shaft, but I didn't see a place for a set screw to secure the key in the keyway. Any idea how they keep it from coming loose?

With either of our suggestions the dish should probably be supported independently of the motor shaft to avoid bearing failure.
Author:  doncaparker [ Mon Aug 15, 2022 11:48 am ]
Post subject:  Re: Spinning radish dishes
Clay--

Machinists can explain keys better than I can, but there is a notch (a key way) in the shaft (if it is designed for keys), and there is a notch in the pulley (or whatever it is that you are attaching to the shaft). A key fits in the lined up notches, taking up all the space of both notches, which allows the shaft to transmit its rotational force to the pulley (or whatever). No need for a set screw.

I have no idea whether the particular part I linked to will work. I figure Bob needs to start from what the shaft looks like on the motor he has, and obtain what will work with that shaft.
Author:  Pegasusguitars [ Mon Aug 15, 2022 12:20 pm ]
Post subject:  Re: Spinning radish dishes
All useful ideas on the journey. Thanks. Tomorrow I'll go by the local industrial motor repair shop. They see all kinds of contraptions and have been helpful with design ideas in the past.-Bob
Author:  Barry Daniels [ Mon Aug 15, 2022 9:24 pm ]
Post subject:  Re: Spinning radish dishes
Don, there is usually a set screw which helps to hold the key in place. Otherwise it can slip out and there is nothing else that is preventing the pully from slipping lengthwise down the shaft. I worked in a machine shop for a few months a long time ago and one of my jobs was cutting keyways into valve bodys.
Author:  doncaparker [ Mon Aug 15, 2022 9:48 pm ]
Post subject:  Re: Spinning radish dishes
I stand corrected, Barry. I don’t deal with it frequently.
Author:  Clay S. [ Mon Aug 15, 2022 10:15 pm ]
Post subject:  Re: Spinning radish dishes
Hi Don,
I am familiar with keyways on motors and pulleys, but those I have used had a set screw to secure them (as Barry mentioned). The bushing you linked to doesn't, so must use some other method. It was an honest question I posed. Perhaps you are right - a tightly fitted key forced into the keyway may be all that is needed to keep the bushing in place.
Author:  doncaparker [ Mon Aug 15, 2022 11:22 pm ]
Post subject:  Re: Spinning radish dishes
I think I remember using a key without a set screw once, but I’m not sure. In any event, the important point is that when you are McGyvering something like this together, you start with the things you already have and buy the rest to match.
Author:  Pegasusguitars [ Tue Oct 11, 2022 1:43 pm ]
Post subject:  Re: Spinning radish dishes
Back in August I started this thread when I finally decided to build a radius dish spinner. Only took me 40 years of procrastination. Just thought I'd show what I came up with. This not an AFFORDABLE spinner. I just happen to have been able to source some used and recycled parts. To build it with new parts would be prohibitive for many builders. It is a real dream to use. A friend was upgrading his lathe to more H.P. and a digital speed control, so I was able to acquire a used 1 1/2H.P. variable speed DC motor and the speed controller. Since the motor is variable speed, the set up is simply direct drive. My machinist does a lot of aluminum work for some of the astronomy centers here, so he just happened to have a 1/2" x 15" disc already cut. It was already set up with a center hole and 2 holes near the perimeter. All I had to do was thread them for the center pin and 2 drive pins. He machined an adapter collar that bolts to the aluminum platen and fastens to the motor shaft with 3 set screws that fit into the keyway on the motor. The 15" diameter aluminum platen is the same size as my uke dishes. It seems to be fine for my guitar dishes too. The dishes just slip on and off the drive and center pins. No bolting needed.The spinner has tons of torque at even the slowest speed. There was some concern about the vertical load on the motor, but my local motor shop seems to think it is not a problem. We'll see! Happy sanding!-Bob
Author:  Glen H [ Tue Oct 11, 2022 2:22 pm ]
Post subject:  Re: Spinning radish dishes
Wow, like that!
Author:  Clay S. [ Tue Oct 11, 2022 2:57 pm ]
Post subject:  Re: Spinning radish dishes
Nice!
Repurposing someone else's cast offs is fun, especially when they are high quality parts you would not otherwise buy.
Author:  SteveSmith [ Tue Oct 11, 2022 3:49 pm ]
Post subject:  Re: Spinning radish dishes
That’s very nice Bob, I’m jealous - ha. I have thought of building one but I simply don’t have the space.


Steve
Author:  Pegasusguitars [ Tue Oct 11, 2022 4:39 pm ]
Post subject:  Re: Spinning radish dishes
Steve, I don't have the space either, but I'm 76 and it has been on my bucket list for so long that I just had to finally do it. Mostly it will sit in the corner with stuff piled on it.-Bob
Author:  SteveSmith [ Tue Oct 11, 2022 5:22 pm ]
Post subject:  Re: Spinning radish dishes
Pegasusguitars wrote:
Steve, I don't have the space either, but I'm 76 and it has been on my bucket list for so long that I just had to finally do it. Mostly it will sit in the corner with stuff piled on it.-Bob


At 70 I'm still a kid, maybe in a few years :D I do find myself trying really hard to make tasks easier and driving the bus is sure one of those tasks!
Author:  Michaeldc [ Wed Oct 12, 2022 6:33 am ]
Post subject:  Re: Spinning radish dishes
If you don’t want to take up as much space, go vertical. This takes up less than 2.5 square feet.

M
Author:  Clay S. [ Wed Oct 12, 2022 7:24 am ]
Post subject:  Re: Spinning radish dishes
SteveSmith wrote:
That’s very nice Bob, I’m jealous - ha. I have thought of building one but I simply don’t have the space.


Steve


One of the nice things about the Bosch mixer sander is that the Mixer fits in a wall cabinet and the disc fits against the wall. Having the disc removable allows the discs to be easily changed and could allow the motor unit to be made more compact. Bob opted to make the unit free standing with storage for the other discs underneath, but a smaller motor housing could be made that would clamp to the bench for stability if space is at a premium.
Occasional use tools do seem to attract clutter (in my shop any flat surface is at risk). I have a cheap table top spindle sander that sits on a rolling cabinet and I have to unbury it when I need to use it - too much stuff! I should adopt my old friend Duffy's mantra - "I've got to get organized" Somehow he never did....

Hi Bob,
A 1 1/2 hp motor may have pretty good thrust bearings, but a fairly cheap option to remove much of the axial load would be to mount some ball transfer casters between the top of the box and the aluminium plate. Probably not needed for the intended purpose, but sometimes we find other uses for our tools that put unexpected loads on them.
https://www.casterspecialists.com/colle ... estselling
Author:  Pegasusguitars [ Wed Oct 12, 2022 12:17 pm ]
Post subject:  Re: Spinning radish dishes
Clay, I have thought of that. I don't think I'll need the extra support, but if I burn through a set of bearings I'll go that route. The best support I've seen lately is to use a half dozen skate board bearings . The builder just routed a groove in the table top and the bearing shaft was recessed into that. The bearings run straight and don't rotate, but that did not seem to matter.-Bob
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