Union Tool & Cutter Grinder Restoration Shenanigans

[Dapph2]

Here are a few more pics of it earning its keep. Ages ago I bought a cheap circular saw blade sharpening machine for my tracksaw blades. It was terrible, grinding different amounts off each tooth, and I ended up sending it back.

So here's the Union, with a resin bonded diamond dish wheel, correcting the errors of that other machine on a few of my carbide blades:

View attachment 507123

I'm learning as I go, but it sorted them out a treat:

View attachment 507125
View attachment 507126

Well this T&C grinder came up for sale while I was in the middle of a bathroom remodelling project. I have to say SWMBO has been exceptionally patient up to now, but I must now resume my work on the bathroom.

Nonetheless, I hope to add to this thread in the future. I'd like to find a way to protect the ways, which are a bit exposed during surface grinding, and I'd definitely like to improve the lubrication system. I have a mist coolant system which might lend itself well to this grinder, and I may even experiment with giving the Z feed a bit higher resolution at some point. I love these restoration projects. I love reading what others have done, and I love carrying out what I can do as well. I think the Union/Harrison is a brilliant, beautiful machine. I would want one even if I didn't have a use for it!

Feel free to chime in with any questions, answers, or suggestions.

Thanks for reading, Paul

On Fizzy's mill and lathes I have cleaned their ways with a spray of WD40 ., used a nylon tooth brush to get the big stuff out them out , give them another spray a few minutes later to loosen any ferrous metallic particles and follow along the ways with a super strong magnet in a plastic tub so the loosened particles are pulled out . To get them super clean of aluminium /brass I used a WD 40 damped Jay cloth on a lollipop stick or T shaped tool made from Delrin to rub & polish them clean .

 

[Dapph2]

The bathroom's finished, so I've been able to spend a little more time on the Union. Mine came with only the extended wheel hubs, which is great because they seem to run true and you can remove them without removing the grinding wheel from the hub. However, the extended hubs aren't so useful for cup wheels - it makes them stick out too much.

I don't know exactly what the non-extended hub looks like, so I originally made one based on photos online:

View attachment 517834
It's really just a glorified spacer. It goes over the 1/2" motor spindle, tightened with the 2BA grub screw. You put the grinding wheel on with a 5/8" ID, then a thick keyed washer, and finally a nut which screws directly to the spindle thread. It works well, and is used on the pink cup wheel I've shown on some pics above.

So far so good, but I want a hub that retains the grinding wheel when you take it off, because I have some super-abrasive wheels I want to use, and I don't want to have to dress them every time. So here's a prototype, based on the types of hub that come with Chinese D-bit grinders:

View attachment 517836

This one has a 20mm hub for the grinding wheel, and an M18 thread for some kind of nut to secure the wheel. As well as its 1/2" outside thread, the Union motor spindle has a 1/4" internal thread, so you can fasten this hub securely onto the spindle with a 1/4" BSW Allen bolt. Which is great until you want to get it off. The standard D-bit hubs include a thread for a jacking screw, and you can do the same with the Union:

View attachment 517837
I've put in an M8 internal thread. The 1/4"BSW bolt just passes straight through it, but when you want to remove the hub, just remove the 1/4" Bolt and use an M8 to jack the hub from the spindle.

Here it is fully assembled with wheel, washer, and a pin nut, then attached to the Union with a 1/4" bolt:
View attachment 517838

And here I am removing the whole assembly with an M8 jacking bolt:

View attachment 517839

On the whole it works really well, and the removal mechanism should ensure my spindle remains true, since I won't have to use pullers, hammers etc.

The only issue I haven't addressed is that the Union allows you spin the wheel in both directions, and one direction could cause the nut to spin off with disastrous consequences! Harrison dealt with this by using a keyed washer, but I don't have the brazing gear necessary to make one of those, and it won't necessarily stop the nut spinning off anyway. I might just use a pair of M18 nuts, locked together. I'm open to suggestions - this is only a prototype. But for now, I've just put an arrow on the hub indicating the correct direction of rotation.

More to come. I want to have a go at making some precision flat stones, for which I need better dust extraction than my copper pipe bodge. I haven't found a decent dust extraction nozzle you can buy yet. I'm looking at modifying a woodworking one, or even a plastic drainpipe shoe.

Paul

Would having a vertical slot extractor hood similar to the power saw blade cover be better than the tube as air will be drawn in from the bottom and both sides of the wheel . Seem to recall such an extraction hood being on a grinder

 

[Dapph2]

The bathroom's finished, so I've been able to spend a little more time on the Union. Mine came with only the extended wheel hubs, which is great because they seem to run true and you can remove them without removing the grinding wheel from the hub. However, the extended hubs aren't so useful for cup wheels - it makes them stick out too much.

I don't know exactly what the non-extended hub looks like, so I originally made one based on photos online:

View attachment 517834
It's really just a glorified spacer. It goes over the 1/2" motor spindle, tightened with the 2BA grub screw. You put the grinding wheel on with a 5/8" ID, then a thick keyed washer, and finally a nut which screws directly to the spindle thread. It works well, and is used on the pink cup wheel I've shown on some pics above.

So far so good, but I want a hub that retains the grinding wheel when you take it off, because I have some super-abrasive wheels I want to use, and I don't want to have to dress them every time. So here's a prototype, based on the types of hub that come with Chinese D-bit grinders:

View attachment 517836

This one has a 20mm hub for the grinding wheel, and an M18 thread for some kind of nut to secure the wheel. As well as its 1/2" outside thread, the Union motor spindle has a 1/4" internal thread, so you can fasten this hub securely onto the spindle with a 1/4" BSW Allen bolt. Which is great until you want to get it off. The standard D-bit hubs include a thread for a jacking screw, and you can do the same with the Union:

View attachment 517837
I've put in an M8 internal thread. The 1/4"BSW bolt just passes straight through it, but when you want to remove the hub, just remove the 1/4" Bolt and use an M8 to jack the hub from the spindle.

Here it is fully assembled with wheel, washer, and a pin nut, then attached to the Union with a 1/4" bolt:
View attachment 517838

And here I am removing the whole assembly with an M8 jacking bolt:

View attachment 517839

On the whole it works really well, and the removal mechanism should ensure my spindle remains true, since I won't have to use pullers, hammers etc.

The only issue I haven't addressed is that the Union allows you spin the wheel in both directions, and one direction could cause the nut to spin off with disastrous consequences! Harrison dealt with this by using a keyed washer, but I don't have the brazing gear necessary to make one of those, and it won't necessarily stop the nut spinning off anyway. I might just use a pair of M18 nuts, locked together. I'm open to suggestions - this is only a prototype. But for now, I've just put an arrow on the hub indicating the correct direction of rotation.

More to come. I want to have a go at making some precision flat stones, for which I need better dust extraction than my copper pipe bodge. I haven't found a decent dust extraction nozzle you can buy yet. I'm looking at modifying a woodworking one, or even a plastic drainpipe shoe.

Paul

Low / medium strength Loctite might be the solution to stopping the Allen screw working loose . If you can't free a Loctite'd screw , try heating an Allen key and inserting it for a few seconds in the cap head the heat ought to soften the Loctite.