Bench Grinder Table 90% completed

The new Bench Grinder table is almost done, still need to do the electrical wiring and build some proper tool rests.

Thanks to Jeremy Blubaugh @teksmrt , Joe Gursky @jfgursky , Jim Kreter @MTLmanglr , Michael Royal @michaelroyal , Jerry and Michael Breitling @jerry_breit, Max Holthaus @Mrholthaus who cut the angle iron, recut the angle iron due my miscalculation, Leveled the cast welding table, practiced tig and mig on the Bench grinder base, drilled and tapped and mounted the bottom plates for the adjustable leveling feet, mounted the grinders and signage, and Charles Procter @procterc who initiated the project in his quest to spiff up the metal shop and reduce the furniture and debris.

I’m not sure if these were his exact words but I seem to recall something along the lines of “It’s a metal shop, why would we have furniture in a metal shop, we’ve got to get rid of the wood things”

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Mounted the disconnect and put some fresh cord on to accommodate the longer space.

To complete the wiring two things are needed: a nema 15-p for the inlet to the disconnect, and the estop button needs an appropriately sized cable gland since a thicker cord was used. It is not currently mounted to the table.

The disconnect has the LOTO lock for now since I have actually encountered a silly enough member to stick a new plug on something.

During the process I found this on the bottom shelf: I really hope someone wasn’t planning to wire this table with it.

Overall it looks great, but some questions about a couple of design choices:

  • the under table unit is a bit low for practical use; leaving over to use it whilst holding a steel object isn’t good for an operator’s back. Additionally if anything catches the operator will be even more off balance leaning in toward the table.
  • the bolting of the top grinders makes them harder to move around for both service and using with larger/obtuse objects. Yes, the table has slots for lots of different placements but those would require moving the bolts. If someone were putting enough pressure into those delta units to shift them on a flat surface, then they’re using too much pressure for grinding. Bolting grinders of that size is typically reserved for use with pedestals.

As for “why do we have furniture” the previous stands were actually grinder or tool stands of one kind or another, just very old ones. One of them I think still has the operator control pedal attached on the bottom right we never used.

The interlock was wired to the wall today with the new plug; it still needs some sealant put on the estop before it’s mounted to the table due to the gland being busted, or a different button that’s better sealed. I didn’t want to drill mounting holes in the legs until we figure it out for sure.

In the time since the grinders were moved one of the wheels was already loaded with aluminium. I got it dressed enough to ring and not have the visible veins, but the wheel needs to be replaced.
The wheels from MSC’s plastic bushings don’t conform well to our motor shafts either. The Sait wheels fit very well with theirs. On the left grinder with one of the new wheels there was enough slop in the wheel it’s likely contributing to that unit vibrating more. Is there a reason we switched? We could probably resolve the bushing issue but unless there’s a reason for those specific wheels it seems like effort for an unnecessary change. If we’re going to stick with those wheels we should get a different dressing tool as it seems they are slightly wider than the others in tolerance. The tool we have was already tight on the Sait wheels.

This grinder table also resonates like a beast. Even with the motor off as it winds down the whole table resonates and you can hear it increasing and decreasing periodically with the wheel speed changes; one of the legs bolts rattled off level just testing things out.

It’s going to need some serious vibration dampening. The grinders should also probably be unbolted from the table, or should have the holding force reduced. They’re large enough if you’re using enough force to push the grinder it’s too much. Typically bolting these 8 inch units is meant for pedestal use. The compression reduces the efficacy of the existing vibration pads on the rubber feet. We didn’t have this level of vibration on the old grinder tables.

Has anything been done to deal with the vibration issues? Or determined what is going to be the wheels going forward? Made a new bushing? Anything?

Seems that so much effort was put into making the original table to leave it worse off than we were when we started.