Does anyone out there have plans for making one ?. I/ve looked around and can/t find anything. Getting very tired of turning that radius dish
. I have 2 radius dishes 1 is a 15 ft for the back and 25 ft for the top Thanks
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| Author: | ernie [ Mon Jan 16, 2017 1:38 pm ] |
| Post subject: | Motorized radius dish sander |
Does anyone out there have plans for making one ?. I/ve looked around and can/t find anything. Getting very tired of turning that radius dish . I have 2 radius dishes 1 is a 15 ft for the back and 25 ft for the top Thanks
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| Author: | meddlingfool [ Mon Jan 16, 2017 3:19 pm ] |
| Post subject: | Re: Motorized radius dish sander |
Search Michaeldc, he put up a post recently of his awesome one. |
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| Author: | ernie [ Mon Jan 16, 2017 7:22 pm ] |
| Post subject: | Re: Motorized radius dish sander |
Thanks ed , I did see it , But I/m looking for something easier and simpler to build that can be moved around. I/m also not confident that I could make the same one as Michael. |
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| Author: | Bri [ Mon Jan 16, 2017 8:01 pm ] |
| Post subject: | Re: Motorized radius dish sander |
Ernie, on a slightly different note(no pun intended), I found that sanding on the disc was not that enjoyable. Now I lay the glued up sides, neck and tail blocks on the disc, scribe it with a pencil, and plane to fit with a small block plane. Usually a 102 or a 60-1/2. I do not use or buy any abrasives for the disc anymore. Usually takes two or three go-rounds but is pretty quick. May touch up with a small block sander. I marked the disc with centerlines to try and set it back to the same general position. Something different anyway. B |
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| Author: | Clay S. [ Mon Jan 16, 2017 8:53 pm ] |
| Post subject: | Re: Motorized radius dish sander |
"I/m looking for something easier and simpler to build that can be moved around" Someone gave me a motorized bowling ball spinner. I made a flat topped plug where the ball would normally sit and mounted a radius dish on top of it. It is portable and not too hard to construct if you have a ball spinner. It is similar to this one: http://www.ebay.com/itm/Innovative-Vert ... Sw2xRYeoJ5 |
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| Author: | ernie [ Mon Jan 16, 2017 9:57 pm ] |
| Post subject: | Re: Motorized radius dish sander |
Thanks Brian , what you describe is what I am currently doing, but after the linings are put in . Will try it after the blocks are put in, and before the linings are glued . I am spending too much time sanding,So need to up my scribing skills. I/m using a scribe compass , I believe LV sells.them . . I/ve been to the okanagan valley many times. beautiful scenenry .Clay that/s one idea I/ve not thought of, very creative way of recycling a motorized ball spinner . How fast does the ball spinner run .Don/t want to go over 100 rpm . thanks |
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| Author: | truckjohn [ Tue Jan 17, 2017 12:26 am ] |
| Post subject: | Re: Motorized radius dish sander |
What I do is clamp the dish to the bench and then sand about 3 passes. I plane off the high spots (that have sanding marks) and repeat. To get the taper about right - I plane mostly at the headblock end at first. One thing that helps is to have a good sharp block plane that can take a reasonably thick shaving at first. Then - give it another couple passes on the dish and repeat planing till you get to the head and tail blocks and have nice even sanding scratches all the way around. No way I could sand the entire way there.... Thanks |
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| Author: | doncaparker [ Tue Jan 17, 2017 6:53 am ] |
| Post subject: | Re: Motorized radius dish sander |
Ernie-- I don't have plans, but I can offer these suggestions on how to build a pretty dandy motorized dish sander without spending a ton of money: To slow the speed down, start with a slower motor (1750 rpm) and use pulleys and belts to cut the rpm via ratios. If you have a 1750 rpm motor with a small pulley, have that belt drive a large pulley mounted on a shaft. On that same shaft, mount another small pulley. Have that small pulley drive a large pulley on the drive shaft, and mount some sort of drive pin attachment on the end of the drive shaft, where you mount your dished workboards. I can't give you exact numbers, because I don't know what motor, pulleys, belts, shafts and bearings you have access to. However, this is how you get the speed down to the range you want. The ratio between pulley sizes cuts the rpm by that ratio. Having a 2" pulley drive an 8" pulley cuts the rpm to 25% what it was before. I think that's how it works. It has been a while since I built mine. When you do that twice as I have suggested, you can easily get down into the 100 rpm range. You just need to pick the right pulleys. For a cheap motor, small pulley and belt, I have been successful buying a cheap belt/disk sander from Harbor Freight ($65 or so), harvesting those parts, and getting rid of the rest as scrap. If you need photos, I can maybe find time tomorrow to take a few. I fully agree with planing wood away before sanding, but even then, I am not wild about driving the bus. I really like having the motorized dish sander. |
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| Author: | ernie [ Tue Jan 17, 2017 8:07 am ] |
| Post subject: | Re: Motorized radius dish sander |
Don , thank you , if you can post the pics that would be great for OLF ers who are into DIY. HF is close and I do buy small stuff from them . I got their 6by 48 sander and it/s one of their gems. John I do also use an occasional block plane. I think i will use all those techniques in conjunction with one another . Am not fond of sandin dust and neither is mrs kleinman. So I will use white tape to highlight my scribe lines plane down to the line add the linings .Come back and pencil the back arch sand the linings ,remove high spots with a plane. Use the motorized radius dish to get the arch correctly. It seems that a combination of all these techniques will help.. I watched a few videos by I built it ca. john heisz and matthias wandel about making pulleys. I/ve bought pulleys from the local ace hdware , and they were disappointing.I/ve also gotten them from grainger and MSC, and other supply houses. Thanks for your help guys much appreciation. |
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| Author: | ChuckB [ Tue Jan 17, 2017 8:26 am ] |
| Post subject: | Re: Motorized radius dish sander |
In this link it shows mine and a few other versions of a motorized dish sander. Mine is built very simply and now hinged to the side of my bench. I don't use it much anymore because of the dust, and do what Bri suggested and finish up with a few passes by hand with the dish,, which takes about the same amount of time. viewtopic.php?f=10101&t=30730&p=407683&hilit=dish+sander#p407683 Chuck |
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| Author: | Clay S. [ Tue Jan 17, 2017 1:08 pm ] |
| Post subject: | Re: Motorized radius dish sander |
." How fast does the ball spinner run .Don/t want to go over 100 rpm . thanks" I think most of them are designed to run about 500 rpm with no load, but with the plug and dish I would guess maybe 200 rpm. It doesn't take long to sand a set of rims. With moderate pressure you can remove 1/2 inch of rim per minute. I use light pressure and take measurements to gauge my progress and avoid the Manzer wedge effect.. I sometimes cut my blocks to length, glue them into the untapered sides, and sand the taper into the body using the dish. I think there are better designs, but it is fast and portable. |
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| Author: | doncaparker [ Tue Jan 17, 2017 10:00 pm ] |
| Post subject: | Re: Motorized radius dish sander |
Ernie-- I know I promised some photos of the innards of my dish sander, but I put safety panels on the front and back, and they are a bit of trouble to remove, so let me just give you more detail. Like I said before, the motor is a 1750 rpm motor I harvested from a Harbor Freight belt/disc sander. The small pulley attached to the motor came from that, too. That pulley is very small, like 1.5". I have it driving a 5" pulley, I think. Then that pulley shares a shaft with another tiny pulley (I can't see it to estimate the size). Then that pulley drives a big pulley on the drive shaft, maybe a 12" pulley. I think I remember it all coming down to maybe 85 rpm or so at the sanding dish? Anyway, like I said before, I don't know what you have access to, so see what you can get, do some sort of double pulley ratio magic, and you should be in good shape. Sorry I can't give interior shots. |
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| Author: | Ben-Had [ Tue Jan 17, 2017 11:47 pm ] |
| Post subject: | Re: Motorized radius dish sander |
ernie wrote: Does anyone out there have plans for making one ?. I/ve looked around and can/t find anything. Getting very tired of turning that radius dish . I have 2 radius dishes 1 is a 15 ft for the back and 25 ft for the top ThanksHere's a rough plan. |
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| Author: | ernie [ Wed Jan 18, 2017 8:37 am ] |
| Post subject: | Re: Motorized radius dish sander |
Ben does the shaft need to be 5/8 th in ? . Will it work with a 1/2in ?? shaft?? then all the bearings /pulleys etc would have to match the 1/2in diameter . Or is the 1/2in just not strong enough ?? to withstand the weight of the 24in MDF and backer?? |
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| Author: | Michaeldc [ Wed Jan 18, 2017 12:12 pm ] |
| Post subject: | Re: Motorized radius dish sander |
ernie wrote: Ben does the shaft need to be 5/8 th in ? . Will it work with a 1/2in ?? shaft?? then all the bearings /pulleys etc would have to match the 1/2in diameter . Or is the 1/2in just not strong enough ?? to withstand the weight of the 24in MDF and backer?? Tim's design is pretty much exactly like mine except I use a 3/4" keyed shaft from a mini bike (eBay), and am using 1/2" X 1-1/2" pulley in the motor, and a keyed 3/4" X 14" on the shaft. With a 1725rpm motor I'm turning about 180rpm at the shaft. IMO a 1/2" shaft it too light and trying to find a face plate in 1/2" is gonna be tough. The shopsmith plate and the lathe plate I'm using are easy to get on eBay and are relatively inexpensive. M |
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| Author: | doncaparker [ Thu Jan 19, 2017 5:58 pm ] |
| Post subject: | Re: Motorized radius dish sander |
I'm bumping this thread to add a reference to another thread that highlighted some features I really liked: viewtopic.php?f=10101&t=48649&hilit=dish+sander I like my own sander's pulley system for reducing the speed, and I already own all of the stuff to make that work, so I am sticking with it. However, the features of Mike Frank's sander that I just love are: 1. The ball bearing casters. Simple, effective, quiet, and not too expensive. Ticks all the boxes. I currently use a large lazy Susan, but I am switching as soon as I get around to it. 2. The use of the sprocket with an offset drive pin to drive the dish, with the drive shaft going up into the dish a bit. I currently have an extra pulley into which I have threaded some equidistant offset bolts, and the bolts are all that engage the dish. It allows a little bit of wiggling to occur. I am switching to Mike's idea as soon as I can. I don't know why I didn't originally see the wisdom of having the drive shaft go into the dish a little. It guarantees circular movement with no slop. |
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| Author: | Pmaj7 [ Thu Jan 19, 2017 6:13 pm ] |
| Post subject: | Re: Motorized radius dish sander |
How are you all finding the exact center of your dish? It seems like if you were off even slightly the whole thing would be lopsided and start wobbling like crazy and your shop would end up sinking into the Earth. |
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| Author: | doncaparker [ Thu Jan 19, 2017 6:31 pm ] |
| Post subject: | Re: Motorized radius dish sander |
Going at a mere 85-100 rpm keeps that death vortex in check, Pat. Even with some moving around (like I said above, my current, inadequate setup allows more movement than I want), it still is not a very big deal. Now, how to find the center of the dish, if you didn't make the dish yourself and thereby create a center hole: I would use a yardstick to find the widest point of the dish, mark the center, then turn the dish 90 degrees, do it again, and a few more times of this until there is a cluster of centers. The center of that cluster is a pretty reliable center. |
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