My new disc grinder

RickA

Well-Known Member
Hi Everyone

When I made the knife for my boss a couple of months back I tried out dovetailed bolsters for the first time. I used a friends little chinese (Ryobi) belt/disc grinder combo and it did the job, however for long term use with bolsters, flattening and squaring handle scales etc I decided to build my own double ended disc grinder. Similar to my 300mm/12" contact wheel which I made last year, I made my own discs out of 235mm dia Aluminium offcuts from a local Non Ferrous Metals supplier. To make the two discs cost around R180 ~ $18 and a few hours work on a lathe (it's probably not neccessary in the USA, but in South Africa this is a fraction of the price of buying the discs / wheels from a supplier). One of the offcuts was a bit too thin to turn a "hub" so I had to have a boss for the hub welded on.

The motor is a 0.75KW / 1HP 3 phase motor. My KMG style belt grinder and the new disc grinder sit next to each other on the bench and both run off the same VFD (alternately - not at the same time)

I designed and built a swiveling frame to allow the grinder to sit in one fixed position on the bench but still allow me to access both discs from the front. I welded the frame up and painted it last week. Tested it out yesterday and it works like a dream, its definitely going to be a valuable addition to the shop. I would still like to add a horizontal disc grinder with interchangeable discs for quickly and easily changing grits as well as a horizontal "mini wheel grinder" - but those will come in time, for now I need to get back to making knives and not making more machines.

DiscGrinder (1 of 1).jpg DiscGrinder (5 of 6).jpg DiscGrinder (4 of 6).jpg DiscGrinder (6 of 6).jpg DiscGrinder (1 of 1)-2.jpg

At the end of March we had a bladesmithing hammer-in at our knife club here in Cape Town. We arranged for the chairman of the South African Bladesmiths Association, a full time pro knifemaker and Knifemakers guild member to fly down for the weekend and run the hammer-in. A very good day was had by all and a lot of new bladesmithing converts were created, myself included, as a result of the fun I had on the day I am currently building a small gas forge and have started trawling the local pawn shops, flea markets etc looking for decent old hammers, anvils etc.
 
Rick, That is slick!!! Good work. I think I'll use your idea (with your permission) on mounting the work rest.

Ken H>
 
Thanks for the feedback guys, appreciate it.

I built it based on some quick sketches, but I have had a lot of questions for more info on the design, swivel base etc, so I think I will draw up a set of drawings for anyone who wants to build a similar machine.

@Ken - feel free to use the design any way you want. I have added a few more pictures below which show some more detail. Let me know if you would like any other detail. The semicircular slot cut into the mounting post is centered on the top surface corner of the workrest directly above the mounting post (hope that makes sense?), to allow the workrest to rotate around that point, keeping the working edge of the workrest close to the surface of the disc, rather than swiveling away from the disc as it is angled. The lower front face of the workrest is ground at a 45 degree angle to accomodate the rest being angled and remaining close to the disc

NB! - the last picture shows the workrest clamped at an exaggerated angle - only so you can see the details.

DiscGrinder (1 of 1)-7.jpg DiscGrinder (1 of 1)-8.jpg DiscGrinder (1 of 1)-6.jpg DiscGrinder (1 of 1)-9.jpg
 
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I was wondering how you did the slot to keep the tool rest up close to the disk. good work. I think you've covered all I need to make my tool rest for disk.

Ken H>
 
As someone who builds machinery myself, I have to say that I am impressed with your design and execution, Rick.
 
Hi guys

Thanks for the compliments, I appreciate it.
I actually enjoy building them, and I certainly learn a lot every time I do one, I find new ways to do things, stuff to improve etc.
 
Hi guys

Thanks for the compliments, I appreciate it.
I actually enjoy building them, and I certainly learn a lot every time I do one, I find new ways to do things, stuff to improve etc.

Rick,
Also thanks for sharing your concepts and your drawings.
 
That motor is made by TechTop, a brand that I sell. TechTop makes motors that are rebranded thus the CMG branding on the wiring box.

A point of interest for some: Balder is the only electric motor supposedly wholly made in America. Balder is a German company for those who want to buy American.
TechTop makes motors for Balder for their European market.
 
@Laurence - no problem, I will make the drawings available when I have finished drawing them up.

@Wayne - Thanks for the info. I bought my first grinder motor from CMG here when they were still Australian owned (with parts of their motor inventory manufactured in China). Last month when I bought this new motor I found out that in 2012 they were acquired by an American company - Regal Beloit. I assume from the way you describe it that TechTop is the Chinese company which produces the original motors which are then OEM'ed.
 
That motor is made by TechTop, a brand that I sell. TechTop makes motors that are rebranded thus the CMG branding on the wiring box.

A point of interest for some: Balder is the only electric motor supposedly wholly made in America. Balder is a German company for those who want to buy American.
TechTop makes motors for Balder for their European market.

Hello Wayne,
And this brand TechTop sold here in the USA is made where? Since I prefer to buy American.
 
Unfortunately Laurence, as I said it the other post, you really can't buy an American motor. Balders may be made in America but I suspect that some parts are imported and they are German owned, so are you really buying American? If you buy a VW made in Chattanooga are you buying American. For that matter if you buy a Ford are you really buying American, with all their imported parts?

TechTop motors are made in Shanghai .
 
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Wayne,
I understand with all of these multinational corps its difficult to get something that is made in any one country. I still try to buy the product that employes the most people here in the USA.

I try to avoid buying products from china, but that is really next to impossible these days.
I recently wanted to purchased a couple of beach cruiser bicycles for my wife and I to enjoy the boardwalks where we live and get a little exercise.

Impossible! All of the single speed cruiser bikes are made in china. I would have had to get into the big money bicycles to find anything made here and we are just not at that level of biking. So we now have chinese aluminum framed bicycles.

The one thing that I do take solace in is that my Rhino Finger Skins & knives are made here in the USA with steels etc from the USA whenever possible.
 
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