Thread: Tool Post Grinding - Another Go.

Bob
Can you lets know if you use a fixed diamond mount to dress the wheel ?
Perhaps a photo of the wheel dressing method.
Cylindrical grinding because of a point to point contact between the round workpiece & the wheel is very demanding on dressing technique, vibration in the wheel (balance) & or machine to obtaining a perfect finish.
regards
Bruce
ABRATOOL

Hi Bob,
I have only done a small amount of tool post grinding, but that finish looks good to me.
Do you have a job in mind? As it only needs to be good enough for a particular job at hand and is usually only used to get fine tolerances.

I hear those link belts make a huge difference regarding vibration, I am not sure of your belt size and if they make one to suit it.
As you know chasing vibration can become time consuming and a pain to say the least Sometimes even getting down to taking a skim off the pulleys in place on the shaft mounted between centres on the lathe, to get them running perfectly true helps in those final stages to get the last bit out.

You could probably chase the vibration forever and not get it all out, but the results your getting now look fine to me.

Dave

Hello Bruce,

The diamond is held in a Dumore fixture. I position the diamond just below the wheel centreline. The tailstock mount is my idea for dressing when the factory fixture won't fit the work piece. Dumore suggest redressing the wheel before a final finishing grind. A tricky procedure given the care involved in picking up the grind again without removing too much material. How do you fare?

Bob.

I have to agree with Dave, The finnish you have obtained looks fine to me also..
Matt

Hi BT,

Originally Posted by Anorak Bob

Stuart, how's that Waldown behemoth going?

Its not, I've been waiting for you to iron all the kinks out
I made an ISO to JT3 adaptor the other day I would have liked to use it but I dont think I will ever be able to mount on the compound slide so no tapers

As others have said it looks pretty good from here.
The marks you are talking about a parallel to the spindle axis in the third picture?

Is the grinder mounted to the cross slide or the compound?

Be careful trying to get "just below the centreline". I'm not sure it matters to much if you are "a lot below the centreline"(I'd have to think about it a little more) but above would be a bad bad thing. (I'm guessing you know this but maybe someone reading this one day wont)

Did you see my cigarette paper and mark out fliud tip?

Stuart

The photos are not as explicit as I would like Stu. The twin fluoros directly overhead don't help. I tried to take a photo with a jeweller's loupe in front of the lens but the camera focused on the loupe lens not the bar.

The grinder is compound mounted with the slide angled to provide fine infeed. My just below should have read below. I read the warning in the surface grinding post the other day. It sunk in.

And I did read about using spit to attach the rollie paper. Obviously that didn't sink in for me to be whinging about how hard it was to pick up the grind.

BT

Hi Bob,

You might have mentioned it already, but I'll ask anyway. Have you balanced the wheel?

Regards
Ray

Do you know what sort of wheel it is BT?(I always have trouble getting my head around which wheel to use for what)
Like you say, a different wheel might be the thing to try.

Stuart

Hello Ray and Stuart,

Balancing the wheel I have would present a challenge. The wheel is only 2 1/4" in diameter. Dumore do stress the importance of using balanced wheels. Acquiring some original wheels will be my next step.

I've added a page from Norton's Toolroom Grinding handbook, whilst old, it does explain the markings on the wheel.

BT

Hi BT,

Are the Dumore instructions talking about wheels your size? I'd only seen wheels balanced that were fitted to a arbor(?). Goggle has come up with a few ways to balance wheels that don't but I've never tried them.

Stuart

Sounds like you need to build the wheel balancer I sent Bob

Found lots of links to people saying balancing wheels this small isnt needed. They maybe in fact be right. But surely a balanced wheel couldn't be worse than an unbalanced wheel(granted it may not be any better either).
Applescotty's Scrapbook: Grinding wheel balancer
And it should keep BT out of trouble for a few hours lol
Stuart

It's got me thinking. Pete sent me an article the other day about wheel balancing and it is basically the same as the method shown in your link Stuart.

The second grinder I bought, which looked like it has been recovered from a watery grave, provided the replacement motor armature. I could remove the spindle and use it as a balancing arbor and utilize the little weights as shown in Pete's scans and Applescotty's blog.

Now I need a stand. I will still try to obtain some Dumore wheels.

BT

Bob in one of the pages I was looking at someone was using parallels along the flat ways of a lathe. Should work great for wheels your size.
Found it A Poor Man's Grinding Wheel Balancer - The Home Shop Machinist & Machinist's Workshop Magazine's BBS

I dont think your old spindle will work Bob. You need a smooth Dia both sides of the wheel where is sits on the knife edge(or parrallel).



Stuart