Thread: Grinder Refurbishments

Hi Joe,

Originally Posted by jhovel

You know you can get the taper threaded extensions for many sizes of threads and spindle sizes. You should be able to find one that screws straight onto the 1/2" W thread and use that end for a polishing wheel or mop. E.g. http://www.ebay.com.au/itm/280875193010 like this.
Looking good!

Thankyou for the link and the kind words. I've posted a couple of pictures of the grinder shaft on the right hand end. From the circlip to the end of the shaft its four inches in length. I placed a ruler there to give some idea of size. I don't think that an adapter would be needed, however the appearance of mine is not quite as I would have expected. I thought something more like the picture in your link.

Grinder-408.jpg Grinder-409.jpg

Please ignore the cap screws. I used the QCTP to support the ruler.

Hi Guys,

Well the paint has dried and I've got the guard mounted.

Grinder-410.jpg

I found that I'd forgotten that there was a raised ridge on the motor end cap and as a result I didn't make the hole in the guard mounting plate big enough to fit over it. So I made some cardboard packing's to take up the gap

Grinder-401.jpg Grinder-402.jpg Grinder-403.jpg Grinder-404.jpg Grinder-405.jpg Grinder-406.jpg

These pictures show the guard secured by the three 10-24 x 10 mm long Philips head screws. Then in order of assembly the back wheel clamping disc, the plastic hub spacer made from a castor wheel turned down to fit the 51 mm hub of the grinding wheel, the outer clamp plate, washer and LH threaded nut.

Grinder-407.jpg

As can be seen with the guard outer cover in place the gap is quite big compared to the 6 mm on the motor side. I did turn the grinding wheel round so that the recess was towards the motor. I need to thin the washer under the nut somewhat and take about 3 mm of the width of the nut so that I can reduce that gap. I have considered putting a hole in the outer guard so that the end of the shaft can pass through it. If I do that then I will have to make something to protect the shaft end.

Thanks for following along.

Originally Posted by BaronJ

Hi Joe,

Thankyou for the link and the kind words. I've posted a couple of pictures of the grinder shaft on the right hand end. From the circlip to the end of the shaft its four inches in length. I placed a ruler there to give some idea of size. I don't think that an adapter would be needed, however the appearance of mine is not quite as I would have expected. I thought something more like the picture in your link.

Mmmm. I see what you mean. Ideally you would (or get someone to) cuth the large thread into a taper tread all the way to the end..... You could do that by either taking the armature out of the motor or sutting the entire motor on a lathe between centres (the motor housing won;t spin because of the bearings). However, you would need a lathe with a taper attachment to do that. There are a few people here who have large enough lathes with taper attachments here who could do that, but I have no idea how far away they are from you to make this feasable.
One day I hope to be able to things like that with my electronic leadscrew controller, but alas not yet.

Hi Joe,

Thank you for your comments and interest.

I've no problem with stripping the rotor out and machining the shaft. In fact I had considered sawing the excess off and putting a 1/2" whit thread on the end for another wheel.

I've talked to a guy at a place that makes polishing mops and he said that they do mops upto 6" (150 mm) wide, but more interesting you can buy mops in 1/2" thickness increments with solid centres and various bore sizes. He thinks that it might require the use of a solid centre mop and a wooden packing with a soft centre mop on the outside of that held on the tapered bit. The threaded end having a nut and plate just for security.

Anyway the 8" X 1/"2 mops are surprisingly cheap so for just over £8 plus P&P I can get four to fit and make something to secure them. They also sell the bars of polishing compound as well as other related items.

One day I hope to be able to things like that with my electronic leadscrew controller.

This sounds like an interesting project. I hope you will tell me more as you progress with it.

Hi Guys,

Well the grinder itself is very nearly finished. I've done the little bits that needed sorting out and its almost ready to put to work.

Grinder-501.jpg

I've thinned off the washer and the nut so that the shaft is fully covered by the nut. I've also marked the nut with a groove as suggested by Michael, (thanks for that). I didn't know that was done to indicate a left hand threaded nut. However even after doing these modifications I felt that the outer cover was still too far away from the wheel.

Grinder-502.jpg

So I needed to cut a hole in the outer cover to clear the nut, so that I can get the cover much closer to the wheel.

I had earlier spotted a white plastic cap on an aerosol spray belonging to SWMBO. That cap was 36 mm in diameter and 36 mm tall. But I needed some way to fasten it to the outer of the guard. So I hit on the idea of putting a groove around the outer edge of the cap. Now I knew that I have a 35 mm diameter "Qmax" hole punch. Measuring the thickness of the plastic cap it was just 2.1 mm thick on the rim.

Grinder-503.jpg

This is the cap stood on top of the guard.

I had a short piece of 35 mm diameter bar that I could chuck in the lathe three jaw. So I used that to support the edge of the cap pressed onto it and a flat faced live centre in the tail stock to support the free end. Then I used the parting tool to cut a 2.5 mm wide groove around the outer edge of the cap, 1 mm deep.

Grinder-504.jpg

Having done that, this is the result. The cap pushes into the 35 mm diameter hole without it quite dropping into the groove. A firm push with my thumbs caused the cap to locate securely into the hole with the metal edge dropping into the groove.

Grinder-505.jpg Grinder-506.jpg Grinder-507.jpg

These pictures show the result. You can get an idea of how firmly the cap is gripped because of the displaced soft paint round the edge.

Grinder-508.jpg Grinder-509.jpg Grinder-511.jpg

The outer of the wheel guard now fits much more snugly against the wheel and this can be seen in the middle picture. The right hand picture shows how it looks now. I just have the spacers to make and a touch up of the damaged paintwork to do and this end of the grinder is finished.

Thanks for looking.

Hi Guys,

I've finished the grinder for now. The guard is fixed, the painting done. The last three pictures of it.

Grinder-61.jpg Grinder-62.jpg Grinder-63.jpg

Thanks to all those who came along for the ride. Your encouragement is appreciated.

Thoroughly enjoyed this thread Baron, thanks for going to the trouble of posting.

Phil