Looking for Sanford MG-612 Surface Grinder owners

[keeena]

I picked up a Sanford MG just over a year ago. At the time I just had an immediate need to make some valve shims in custom thickness, so I gave it a quick clean up but that was about it. Now I have some real projects and I'm finding there's a bit of chatter. Lots of good info to start with so I won't bog down this thread until I get stuck.

Anyway, I wanted to post up a pic, serial number, etc... There have been a number of questions in this thread and I think most are answered, but please bump if there's anything I can help with. Mine does have a single oiler on the top of the column and a couple inside the column on the dovetails (as well as a bunch elsewhere).

Serial is 1611891M, so looks to be one of the newer ones in the H-M collection (1961, machine # 1891). It came with an Enco (Spain) chuck and a couple of Sopko wheel adapters. Also has the wrap around guard which is a bit harder to find.





In case its helpful: the spindle seal on mine is a Garlock Klozure, 63 x 36 9 I believe this means a model 63; I couldn't find details on the rest of the part #.


Picked up this Magnetool chuck recently - its fine pole so it has a bit better grip than the Enco.


Very tough to get a picture of it, but if you look at the full size picture you can see the slight ripple (chatter) where the lighting transitions at ~4.5cm and 7.5cm on the scale. This is with a 32A46 Norton wheel; material is 4140 normalized.

 

[kevin]

keeena - Thanks for the info. If you would care to share, I'd be interested in knowing what you paid for it, and what "accessories" came with it (mag chuck, wheel adapters, wrenches, etc.)

Do you know if the splash guard is original with the machine, or where someone fabricated along the way? Either way, it looks well made and is a real nice-to-have.

Regarding the slight ripple on the grind: I see a similar pattern on my machine. The motor on my machine is not the original balanced motor; it is a standard off the shelf "farm motor." I have been wondering if this might be part of the reason for the ripple. On the one hand, I was thinking that any motor vibration would be dampened by the belt, but on the other hand I thought that Sanford would not have supplied a balanced motor unless there was a good reason. I also tried running my motor with the belt off, to see if I could detect any vibration - if there was any, it was not detectable by just "feel".

Another reason for the ripple may be that I have not balanced my wheels, other than by dressing them. I'm working on making a wheel balancer, so if I ever get that done maybe I will see a difference. In the meanwhile, while the grinds I am getting are not perfect, they are more than good enough for my purposes.

 

[keeena]

Last year (May 2020) I believe paid either $400 or $500; definitely no more than that. It came with the base, Enco mag chuck, 2 Sopko wheel adapters, the Sopko wrench & puller, 2 diamond-nib dressers, and a few grinding wheels (one used, 3+ new). IMO this was a fair price. I attend machinery auctions here/ there and feel you could get a better built 6x12 machine in the same price range. However, that takes time and condition can be all over the map. This Sanford popped up 15min from my house on CL.

I needed some valve shims for a race bike and due to pandemic shutdowns they were on 3+ month back-order from England. I do have standard shim kits but the exhaust? valves on Triumph D675 engines use half-shim sizes which are only available from Triumph. Just a few would cost nearly $60. So like any good tool junkie: I bought a surface grinder instead. End of tangent.

Splash guard is OEM. Projectnut mentioned this in another thread from last year and provided a brochure which showed it. My table has a pipe thread provision for a drain, but it didn't come with a coolant reservoir / pump / nozzle.

My motor is OEM, 120v. It was advertised as precision balanced from the factory. It feels relatively smooth and quiet but I've never operated surface grinders before so I don't have a good reference. The belt and pulleys are likely the first thing I'll be looking at. I also have a little play in the Y (up-down) nut, but my understanding is that this is probably normal. I also would like to look at wheel balancing. I tried a couple different wheels and they do the exact same thing. The pattern is very consistent regardless of feed.

The worst problem I immediately found (other than being dirty & somewhat neglected) was a completely shagged Z-axis leadscrew nut (in-out feed from operators standpoint; would be the Y-axis on a knee mill). The leadscrew had some minor wear in the middle. Replacement was easy enough to make; I did both the nut and leadscrew since I wanted to change to acme thread.

Original Z-axis nut - yeah, she was a little overdue.


Replacement


And new acme leadscrew vs original

 

[kevin]

Thanks for the update. Looks like I need to try some wheel balancing.

Nice job on fixing the Z-axis. I think you paid a reasonable price, especially with the original motor, etc.

 

[projectnut]

Before balancing anything or tearing apart the spindle try using the machine again on different material, and using a bit different startup procedure. Start the machine and let it run for between 10 and 15 minutes before trying to grind anything. This will bring the spindle bearings up to normal operating temperature. Even though they are supposed to be precision bearings there is always more clearance between the races and balls at room temperature than after the machine has run a few minutes.

I was taught that on days when surface grinding is to be done first turn the lights on in the shop then start the grinder. Once it's running go about the remainder of normal everyday shop opening procedures. By the time you have completed the opening procedures the grinder should have run long enough to be fully warmed up.

 

[kevin]

That's a good tip, and easy enough to try.

 

[LAmachinist]

Nice work on the lead screw and nut!

Can you describe or post a pictures of the oiler on the top of the column and the ones inside the column? I have a much older version and there is no provision that I can find for oiling the column. I am re-building mine - currently scraping in the column box ways - and would like to see the details of the later MG design to give me some guidance on where to put oilers.

 

[keeena]

Top of the column has one oil cup about 3" from the side with the Y-axis wheel. I assume this is for the bevel gears. Don't mind the missing Y-axis wheel is for a locking screw.

The spindle mounting plate has 2 cups; I assume these have galleys to direct oil to the ways


While I was back there snapping Polaroids: this is the OEM 1/2hp 120v motor nameplate


Four oilers for the Z-axis - two on the rear way covers, two on the Z-base in front of the table
Two oilers right next to each other in the front- middle of the table for the X-axis ways
One oiler for the shaft of the X-axis handle shaft

There doesn't appear to be any provision for lubricating the Z-axis shaft, either lead screw, or the rack.

 

[DKMC]

Hello,
I have a question regarding spindle oiling on a 6-12 MG. Mine has a sorta funky oiler with a (once) clear plastic dome that is hinged. I don't see any way to fill it. It's located on the spindle near the column. Any info much appreciated.

 

[benmychree]

If its like the one that I,ve seen on a B&S SG, it is filled when it is hinged over, then inverted to feed the bearing.