Trim Tool grinder

I have recently acquired this tool grinder, manufactured in the UK by RJH.



As you can see, it has some kind of sump with a drain plug in the front, which is much deeper than the bottom of the wheel.




I do not have much experience with Tool grinders. What kind of fluid should I use in the sump? Should the fluid level be such that the bottom of the wheel is submerged? Will it splatter all over the place? What sort of extraction system should be used for such a set up?

Is anyone here using a similar machine? I would love to see some photos and hear any tips you may have. I am mainly interested in grinding HSS lathe tools and maybe occasionally carbide. I have some jobs that require special form tools and I’d like to use this grinder to make them.




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AgnewBlues said:

I have recently acquired this tool grinder, manufactured in the UK by Trim Tool.

As you can see, it has some kind of sump with a drain plug in the front, which is much deeper than the bottom of the wheel.

I do not have much experience with Tool grinders. What kind of fluid should I use in the sump? Should the fluid level be such that the bottom of the wheel is submerged? Will it splatter all over the place? What sort of extraction system should be used for such a set up?

Is anyone here using a similar machine? I would love to see some photos and hear any tips you may have. I am mainly interested in grinding HSS lathe tools and maybe occasionally carbide. I have some jobs that require special form tools and I’d like to use this grinder to make them.


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Its a water bowl for dipping the tool into for cooling off when doing basic grinding to shape. Heavy grinding with a coarse wheel rapidly makes things too hot to handle if not dipped regularly.

Yours seems to have a diamond wheel for finish grinding and sharpening so you will need to dip the tool often. It is said to be important to keep the workpiece cool lest overheating at the grinding interface draw the carbon out of the diamond abrasive.

Its arguable whether or not a diamond wheel should dip into the water or not. Ordinary grinding wheels should be run clear of the water, not wet like a woodworkers grinder.

Consider re-vamping the tool support arrangements to give positive stops at the angles you use. I'd do the heavy shaping on the periphery of an ordinary grinding wheel leaving the tool slightly hollow ground so touching up on the diamond wheel needs only a minimal grind.

Clive

That looks like a grinder specifically for brazed carbide tools. Most I have seen have a little cup up above the wheel that would drip water onto the wheel for cooling, and then run off into the collection tray.

I think having a wheel running directly in water would make an unusable mess. Looks like the original table was lost or broken, but it would have been similar. The clearance angles are set with the table, then you run the tool face against the wheel, while on the table directly.

Generally, aluminum oxide face wheels are very hard to find, though I have heard of people buying them custom. Alternatively, you might be able to find an appropriate CBN wheel which can do steel. Generally, diamond wheels are not recommended for grinding ferrous materials because they break down chemically with ferrous materials above 700 degrees C.

Generally, you do not dip carbide tools when they heat up, as they are liable to crack with quick temperature changes.

You can look up Hammond or Baldor carbide grinders to get an idea of why I think that is a carbide grinder, and an idea of how they are used.

QT: [Its a water bowl for dipping the tool into for cooling off when doing basic grinding to shape.[
And it can have a hose added to lead coolant into a 5-gallon bucket or tank. You can install a simple aquarium pump to become a system, or just hang a drip can over the wheel.
hopefully, it can use a 1 1/4 hole wheel and you can use standard plate mounted wheels.
it is a nice little grinder.
Mark the wheel hub and a line-up mark on the spindle so taking it off and back on it will run truer to its wore in state/condition.

Mounting a new wheel use paper shims behind the wheel to make it run to +- .oo1 or so...and add the line-up marks.

A decent coolant is pink liquid hand soap mixed with water. The common pink hand soap is high in washing soda and that is a decent rust preventer... plus you can dump it in the yard with not harming things.
Yes you can just add washing soda to water.. 1/4 cup per gallon is good....not baking soda)

likely that diamond wheel is 100gt of finer..You can bench grind (Ao wheel) lathe tool bits and then tickle grind them on that diamond wheel for a very good edge. you can pick up a dressing stick, or just dress with a piece of broken AO wheel, broken green wheel is the best dressing stick.
Don't plunge a hole in the wheel face, but try to always grind with the wheel high spot to be dressing the wheel flat with all your grinding.

Thanks for the replies everyone, I have been busy with other aspects of the shop and haven’t gotten around to using this one yet. I am hoping to wire it up over the next few weeks and see what it can do.


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Jog the spindle a few times if it has been setting for a time

If you take off the wheel try to mart it so it can be put back in the same radial position, so it will run true to its wore in condition.

An aquarium pump would do Ok for a coolant pump from a bucket of washing soda homemade coolant.

Try to grind at any high place to keep the wheel flat.

I would drill another drain off to the right or left so the drain would not be over the switch.

michiganbuck said:

I would drill another drain off to the right or left so the drain would not be over the switch.

Click to expand...

Or maybe just move the switch - Looks dangerous, where it is .....

Tom A said:

Or maybe just move the switch - Looks dangerous, where it is .....

Click to expand...

Yes, I was thinking I better move that switch.


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