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Powered Sanding Dish Help
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Author:  GregG [ Fri Apr 06, 2007 1:56 am ]
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Hi All,

O.K....so I have looked at and printed everything I could find relative to powered sanding dishes and I still am not exactly sure of the parts and pieces needed to make this thing work. I've looked at different bearings, pulleys and shafts, but hate to make an expensive mistake ordering this stuff without really knowing it is "right". Any thoughts, pics, parts, places to buy, etc. would be greatly appreciated. I've already received some offline help with this and am so grateful for those who offered their thoughts, I'm usually really good at this kind of stuff but this thing is just stumpping me for some reason...HELP!!

Cheers,
Greg
Author:  John How [ Fri Apr 06, 2007 2:10 am ]
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I used ball type flange bearings on mine. I used 5/8" shafts. You'll have to figure out your speed reduction based on your motor speed and the desired final speed. I bought aluminum pulleys from the local hardware store. See Tim's article here. You don't have to follow his plan exactly but it is a good starting point. I'll try to post a pic or two of the internals on mine later.
Author:  Brad Way [ Fri Apr 06, 2007 3:30 am ]
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Greg....you came the right place. I remember researching dish sanders and wondering what the right way to make one. Tim's article was very helpful as well as others (John How, Shane Neifer).

Here are a few pics the sander I made:


(Thanks John How for the idea for the threaded rods to set the sanding depth on the molds.)


3/4 HP Motor with right angle gearbox




Steel dish backing plate with drive pins.

I decided to build my dish sander with a gearbox rather than pulleys because it seemed to simplify things. I purchased the gearbox, motor, motor control, and steel backing plate on ebay and at a local industrial surplus supply. My final dish size was 22" which allows me to to store the dishes in the cabinet. I also built an attachment for routing my own dishes using the dish sander which helped justify making the setup.

Good luck and let me know if you have questions!
Author:  GregG [ Fri Apr 06, 2007 4:41 am ]
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Thanks Gents....Brad, I love what you did, now that is a setup.... what gear ratio is the box? what RPM motor did you use? and what is the final dish RPM. I guess I would need to know if there is a shaft size / motor facing type that would be important as well to fit the gearbox. Any wild guess as to the cost of this setup?

Thanks,
Greg
Author:  Brad Way [ Fri Apr 06, 2007 4:46 am ]
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Cost....$250. I used a 15:1 with a variable frequency drive control. THis allowed me to convert the 3 phase motor to single phase and also allows me to adjust the speed from 1 rpm to 130 rpm (aprox.) The whole project took about 3 months since I was putting it together from parts.
Author:  GregG [ Fri Apr 06, 2007 5:00 am ]
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Thanks Brad, does this system need a 3/4 HP? did the motor and gear housing come as a unit?

Greg
Author:  martinedwards [ Fri Apr 06, 2007 5:37 am ]
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George Lowden has two beside each other using zanussi washing machine motors......



the two pieces of angle iron across each dish are for the mould to sit on, which keeps everything level.



thanks to letseatpaste for the pics!!!!
Author:  Sam Price [ Fri Apr 06, 2007 5:53 am ]
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...And Zanussi washing machine motors are incredibly reliable....what a FANTASTIC idea!!

Just ask my mother and the 7 kids she reared....
Author:  Brad Way [ Fri Apr 06, 2007 7:32 am ]
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[Quote=GregG]Does this system need a 3/4 HP? did the motor and gear housing come as a unit? [/QUOTE]

You will find that there are many opinions on what size motor is required. I originally had planned on a 1/2 HP and based on some feedback from various people I decided to make it 3/4 HP. My guess is that 1/4 HP is too small and 3/4 is plenty of power. (1/2 HP would probably work fine). As for the gearbox...many come with a C face mouting for a motor. As long as the motor and the gearbox have the same size mount then it is only 4 bolts and take just a few minutes. It is fairly standardized. I puchased the motor locally and the gearbox off Ebay. If you can find a single phase motor and the correct ratio gearbox then you can skip the variable speed motor control. In my case it was too hard to find everything so the speed control made it to get the right speed.

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