The Shop > Tools
Bench Grinders & Lathe Tools.
AdeV:
I bought a cup wheel for my bench grinder. It came from a 2nd hand tool shop, so is of unknown provenance, but it's now spent several hours spinning on my grinder with no ill effects. The advantage of the cup, of course, being you can grind flat surfaces... I did have to make a bushing to fit my grinder, but hey - that's why we have lathes isn't it...?
What I really need to do now is make an adjustable tool rest to suit the cup wheel... another on on the Round Tuit waiting list...
chipenter:
I madesometing similar to Harrold Halls grinding rest improovers repeatability no end .http://www.homews.co.uk/page145.html
Fergus OMore:
--- Quote from: AdeV on July 22, 2017, 06:04:47 PM ---hat I really need to do now is make an adjustable tool rest to suit the cup wheel... another on on the Round Tuit waiting list...
--- End quote ---
I'm getting into one of those Eccentric Acute grinder things- or is it two? Bought the bits at Doncaster Show for one.
Lashed out at Axminster and bought a double ended grinder with a 80 grit wheel on one end and a paving stone grit on the other but I want my CBN to go somewhere.
So a hint for those who have problems finding angles and all this tilting stuff. Work on the flat- ie with chipboard or whatever and get the angle with the maths in inches
Dia of wheel x diameter of stone x 0.00088" and crunch the result to the nearest 1/16th and arrange packing up or down on centre of spindle.
Hope this helps!
Norm
Pete W.:
--- Quote from: Pete W. on July 19, 2017, 11:59:38 AM ---
SNIP
I recently made an impulse buy, a modern 150 mm double ended machine. It's rated at 370 Watts but with a 10 minutes ON, 15 minutes OFF duty cycle. The motor runs quietly enough but when I saw how the wheels turned, the expression that came to mind was 'swash plate'!! I've left it too long to ask the seller to accept a return and, besides, the purchase price was alleged to be reduced. In his book, Harold Hall describes mounting an entire double ended grinder on the bed of his lathe and using cross-slide and top-slide to true the grinder shaft ends while it revolved under its own power - I'll probably be trying that some time. The wheel mounting washers are pressings but look to be true enough.
--- End quote ---
I eventually got this grinder to the top of the 'to-do' list. The photos show the complete machine, then various stages of dis-assembly of the RH wheel & guard and finally the dial gauge readings.
The shaft extending from the ball-race has three sections, diameters 14.5 mm, 12.72 mm and thread M12. I measured the peak-to-peak run-out of the two plain sections at between 0.007" and 0.010" (sorry about the mixed units). There's a centre drilling in that end of the shaft and, presumably, one in the LH end also, so I assume that the motor rotor and shaft are turned between centres. I reckon you'd have to do something fairly clever or astonishingly stupid to get 7 to 10 thou run-out that close to the bearing journal and centre!
The shaft surface finish was interesting, not so much a cylinder as a very fine thread, about 75 to 100 tpi! I re-assembled the machine before I up-loaded the photos and the photos don't show the surface finish. If I dismantle it again, I'll take another photo just showing the shaft extension and its finish.
I couldn't measure any run-out in the face of the step between the two shaft sections - the step is too small to give my DTI a satisfactory contact.
The abrasive wheel from that end of the machine lies flat on the surface of my dining table so I think that's not the cause of the swashing motion. I'd like to measure the lateral run-out at the outer edge of the wheel (when mounted) but I didn't want to apply my DTI stem to the wheel. If I think of a safe way to take that measurement, I'll post again.
Right, photos:
Fergus OMore:
Years ago, I had the same sort of trouble which was traced to rotten wheels, out of balance and worse.
From what I have read, it is 'normal' to replace the wheels with something more in keeping with our hobby demands
HTH
Norm
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version