Stone!

[LarsHansen]

Hi.
Just "inherited" an old SuperGrind 1200 in pretty bad shape.
Reason tells me to trash it, but the challenge was too sweet...
Having crushed the stone, it became clear to me why the stone wobbled quite badly. At the top of the hole in the case, the plastic was melted. I intend to draw and 3D- print a patch including a new, enforced hole.
My main problem is to get the hole size and placement absolutely correct.
Would someone with a SG1200 be so kind as to help me with two measurements?
First one would be the correct diameter of the hole in the stone end of the case.
Secondly I would like to know thickness of the enforced ring around the hole.
Thanks very much.
Your's,
Lars

[LarsHansen]

Closeup. Not a pretty sight 

[Ken S]

Lars,

Some of the 1200s had overheating problems which caused the openings to melt. I highly recommend that you email the closeup photo to Tormek support (support@tormek.se).
Please post your reply. We are curious.

Ken

[John Hancock Sr]

The ring is actually the bearing and is made of nylon. There should be another one on the honing side which will be identical to the one on the grinding side. They come with the replacement shaft, which you will need if you repair it. If it were me I would be tempted to make an epoxy repair but a 3D printed part should be fine with 100% infill to make sure it is strong enough.

[LarsHansen]

@ Ken:
WillDo
&
WillDo

But are you sure that they will find the possible shortcomings of an old model interesting?
- - -
@ John:
The odd thing is that as far as I can see, the holes on the honing and grinding sides aren't (or rather; haven't been) the same diameter!
- - -
Thanks for both your inputs.

Lars
That puzzles me

Your's,
Lars

[Ken S]

Lars,

One of the bedrock principles of Tormek is none obsolescence of older models. Support will give you an honest answer of whether or not your 1200 is worth repairing or not. I know the head of support personally. He is a good guy; I have full confidence in him. He has worked for Tormek since long before the 1200, and may have actually worked on the group which built your machine.

Email support. (support@tormek.se)

Ken

[John Hancock Sr]

I can vouch for Tormek's dedication to older machines. Their stated policy (they call it "The Tormek Way") is that every Tormek sold be maintained in working order if possible.

The shaft uses two identical nylon bearings which press into the case into which the shaft runs. So yes, they would originally have been identical.

[LarsHansen]

@ Ken,John

Thanks, I've emailed Support and will get back here when I get an answer.
Lars

[LarsHansen]

After lots of digressions, I finally had time to make a patch. It fits tightly around the nylon bearing of the new, stainless shaft.
Couldn't make it smaller as it had to be skrewed into intact areas of the plastic case.
Not elegant but it seems to do the job nicely. With that in place and the new shaft, it's become annoyingly clear that the honing wheel has warped. It has some ugly cracks, too, so it wobbles heavily. Oh well, one more item to wish for Christmas.

Lars

[Ken S]

Well done, Lars! You have earned your Christmas present.

Ken

[LarsHansen]

Just back from a short holiday, I've fallen behind with getting back as promised.
The friendly guy at Tormek suggested that I patch the hole pretty much the way I had done already. He also kindly offered two new plastic bearings.
Most importantly, he offered good advice for the mounting and maintaining of the new, stainless spindle in the plastic housing of the SG1200:
1) Leave a tiny amount of play when mounting the spindle (and if course; use a bit of grease)
2) A drop of oil on both bearings every now and then.

Should anyone have or come across a Tormek with a similar issue, I'd happily share the STL file for the patch, just contact me.
Thanks again for the response.
Your's,
Lars

[John Hancock Sr]

Very nice indeed. Once again Tormek support step up to the plate.

FYI I use white lithium grease which is recommended by Tormek. I picked up a 500g tub from my local automotive store. It is very sticky and use it for many applications.