New-to-me MTI Qualos surface grinder

[Pete O]

This was kind of an impulse purchase at a machine shop clearing sale, it's been something I've thought would be nice to have but I have to admit to very little knowledge and absolutely no experience of surface grinders. Brought it home last Tuesday and spent several hours on Thursday separating the grinder from the base so I could lift it off the trailer and then beginning to clean it up.
   
The machine was pretty filthy, the base was easy enough to clean with the pressure washer but the grinder itself took all of this afternoon to clean up.
   
   
   
I cleared a suitable space and got the base into position and leveled, then lifted the grinder on and leveled that. Leveling the base with a carpenter's level took probably less than a minute as it has 3 feet. Leveling the grinder itself with a machinist level on the chuck mounting surface took ages but I got there in the end. Got the switchgear housing and the lube unit mounted before calling it a night.
   
The table runs on balls and the x-axis is driven via a toothed belt. All seems to operate pretty smoothly. I don't plan to strip it down any further than I have done just to give it a basic clean. Still have to clean up the guard arrangement and a few minor bits. Also need to investigate the dust collector unit, there is no plug attached to the power lead so I'm wondering if it was removed due to an electrical fault.
When I removed the chuck, this is what I found underneath.
   
and the underside of the chuck itself:
   
Doesn't exactly look like two perfectly mated surfaces, does it?
I've read that the chuck surface should be ground in place after installation. I'm thinking that the underside of the chuck and the mounting surface on the table also need grinding.
My thoughts at this stage are to mount the chuck and get a bit of practice with the machine, just grinding scrap material until I'm reasonably comfortable with it, then do the following:
1; grind the table surface that the chuck sits on
2; mount the chuck upside-down, clamping it down under it's own mag force, and grind the underside
3; mount the chuck to the table and grind the top of the chuck.
I'm very keen to get some feedback from you experienced fellas as to whether this seems like the right approach.

I got a couple of welcome surprises when I started unloading; there was a wheel balancing jig and arbor, a wheel dresser plus the wheel guard that I thought was missing, hiding in the bottom of the machine. I got a bunch of grinding wheels, about 15 or 20 I think, haven't had much of a look at them yet but there are a bunch of different sizes and shapes including a few cup wheels and stuff. Hopefully I'll get a chance to have a better look at them in the next few days and will post some more photos. I'll also have a heap of questions!

[Mike E.]

Before you get started on grinding, consider checking out some of the videos by professionals. Suburban Tool on YouTube is a good example.
Definitely look at surface grinder accidents posted on the internet.

[f350ca]

Nice score Pete, I was in the same position about a year ago, stumbled on one I couldn't turn down. Had never used one either and didn't really have a need for one but who can turn down a new tool.
Im working on the same premise as you, when I learn more I'll grind the magnet. For now a test indicator shows it to be pretty flat anyway. As for the bottom of the magnet and table, I just cleaned them up and used a stone to knock off any burrs so it sits flat. Also lightly stone the table top before each use.
The Suburban Tools videos Mike mentioned are good.
Have fun,

[Mayhem]

+ 1 on the Suburban Tools videos

[Vinny]

Before you grind anything, clean off/de-rust the bottom of the chuck and table top as un-abrasively as possible. Then take a DTI to it and see if it's even going to need grinding.

I was all set to do that with mine seeing as the chuck isn't the one that came with it (none came with it). After completely cleaning, degreasing and degunking it I put the DTI on the table. No grinding necessary. Cleaned up the chuck real good and mounted it. Put the DTI on that and no grinding necessary there either.

[Mike E.]

I've also recently acquired an old grinder which I couldn't pass up, a Herbert Jr. manually operated one. My wife's cousin works for a surface grinding company, and he suggested that I have both the bottom and top of my magnetic chuck ground parallel so that I would have a reference to measure possible table wear; which makes sense to me. Like Vinny, the chuck I have came from another machine.

[Pete O]

Thanks for those tips. Makes sense to run an indicator over the surfaces before I go stuffing it up. I've watched several of the Suburban Tool videos- I think everything I know about surface grinding has come fro there. Haven't seen any disaster clips though, will have a look.
I feel like I've moved into the modern era with this machine- built date 1987 and the only metric machine in the workshop.

[Pete O]

I've spent a bit of time this morning fiddling with the surface grinder- had to make a puller to remove the spindle arbor, set up the balancing jig and balanced a wheel. I have not connected power to the machine yet, may get that done this afternoon.
In the meantime, I have a question about the dust extraction unit. I cleaned it out- shoveled about 10kg of dust out of the bottom of it, gave it a hit with the pressure washer- and noticed that it has a fluid level indicator similar to the gearbox on my lathe etc, a clear plastic plug with a dot in the middle. It doesn't look like it has ever had fluid of any kind in it. I am wondering if this is supposed to have some oil in the bottom as a dust catcher, like an old truck air filter, or is the fluid level window there to tell you it is full if you are using a coolant? There is no coolant system on the grinder.

[Pete O]

I bit the bullet yesterday afternoon and ground the surface of the mag chuck. Having watched Steve's videos (Viperspit) along with some of those from Suburban Tool, and having found a 46j wheel among my pile, I figured it was time.
I found it was quite low on the right-hand end as well as having a big dip in the middle, didn't measure the unevenness as I went, just kept taking .02mm passes until I was contacting over the whole surface. From memory, I think it was only four passes after hitting the high area at the left-hand end that it was grinding all over.
   

I ground the top and face of the rear fence after reinstalling it.
I ran over the chuck with a .002mm DTI this morning, it has no more than one graduation of variation over the entire surface, that's somewhere in the vicinity of .0001".    I think the machine is now capable of doing accurate work, wish I could say the same thing for the bloke operating it.
The surface finish is nothing to write home about but I figure the flatness is the important thing. There are a few deep score marks, as well as a groove along the top surface of the fence. Again, I don't think these will affect the work; experienced operators may be able to tell me otherwise.
In the bottom photo you can see a gouge mark in the very corner of the chuck at the right-hand front corner- the front edge of the chuck is at the very limit of the Y-axis travel and the table lifted into the wheel as I went to wind it in for one more pass. The chuck occupies pretty much the entire available travel in both directions, it was only just possible to get the chuck clear of the wheel at each end.
   
   

Thanks Steve (Viperspit) for the videos that gave me the confidence to attack this.

[Pete O]

Hmm, I just found a video that Steve has posted in the last few days that addresses this subject specifically, several things I did not do when dressing this chuck! Didn't have the magnet on, for one thing, and my method of checking the result with the DTI has been totally undermined.
Oh well, at least I used the correct grade of wheel.