Looking for Sanford MG-612 Surface Grinder owners

[LAmachinist]

Recognizing this is an old thread, I wanted to add information about my Sanford MG grinder. It has been in the family for many decades - originally in NJ. The machine has a standard 3TPF spindle taper, 9/16-18 LH threads, and uses a slotted spindle nut (which I will replace shortly with a hex nut style from Sopko). The wheel adapter that came with it uses a right hand thread, which is incorrect for the rotation direction of the spindle. I am not sure if that was original to the machine or whether someone 'used what they had' at some point. The only modification I have done is to add a coolant pump, nozzle, and a gooseneck light. Despite looking somewhat worse for the wear, the machine is surprisingly accurate.

Serial number is 151-312M, suggesting it is from 1951. I do not know what the 'M' signifies.

I am unsure about the spindle bearings - once the wheel hub was removed and the 'dust cap' that is set screwed to the spindle was removed, I don’t see any evidence of bearings - just something that looks like Babbitt in the spindle housing. I am not yet sure if this is a 'cap' or whether this machine could have had plain bearings.

Anyone have experience with these machine spindles? Can I be sure that there are ball bearings in there somewhere?

 

[kevin]

Never too late! From this source:

"Serial numbers can be divided into four series, Early, Intermediate, Late and Final. The first Model SG grinder made carried the identifier AA1 - the earliest machine known so far in this series being No. A62 - and No. 475 the highest. By 1945 the Intermediate series of numbering had been introduced with the first two digits now indicating the year of manufacture and the last four the machine number - the earliest and latest of this series so far discovered being, respectively, No. 45731 (machine No. 731 made in 1945) and No. 511421 the highest; sometimes a dash is found stamped between the year and the machine number. In mid 1951 the Late series began when a prefix digit "1" was added, Machine No. 1511471 being the earliest so far discovered."

Which would mean your machine is now the earliest 1951 machine discovered. My own guess is that the M indicates the MG model, and I note that your machine is marked at the top as a Model MG.

I do not know if any of these machines were manufactured with babbitt bearings but that seems unlikely to me. If your spindle used babbitt bearings it would need to have some means of oiling the bearing, and there does appear to be an oil cup in one of your photos. I have only seen photos of a handful of MG models, and none of them have that oil cup. Did Sanford make some machines with babbit bearings? Did somebody retrofit your machine? Your guess is as good as mine (maybe better!). I'll be interested to hear if you find out for sure one way or the other.

In case you have not already seen it, my web page has a bunch of links to Sanford info:

Academy of Lagado - My Surface Grinder - 1

Sanford MG-612 Surface Grinder - and Related Resources Includes info on the Harvey Butterfly LG8-12 Surface Grinder [4/14/2018 - create page]

sites.google.com

 

[projectnut]

A I noted in an earlier post my Machine was built a little later than yours with a manufacture date of 1954. When the "dust cap" is removed there is a bearing seated about 2" farther into the housing. You'll need a light to see it. The bearing has an identification number of 205ZZ etched into the race. 205 is a standard size 1" ID bearing. I believe the suffix ZZ indicates it's a higher class bearing than the more common ones used in an automotive application . It's been some time since I've looked into the spindle, but as I recall Sanford used what they referred to as part # SG E-15. There is also a note in the manual mentioning spindles prior to serial #151-5100 must be replace due to the discontinuation of spindle bearings E-14.

As for the hub it is quite possibly the original. Mine also has a right hand thread. If you use a washer with a retaining tang between the nut and the wheel the right hand nut will work fine. I've put in the neighborhood of 100 hours on the machine, and never had a problem with the nut coming loose. Having said that I also have another hub with left hand threads. They both work equally well.

 

[LAmachinist]

Thank you for the replies - lots of good information here and on the links you provided! I had seen a generic manual that mentioned the change in bearings and possible unavailability of the old style bearings. I have also put many many hours on this machine, and have had almost no problems with the right hand wheel adapter. Still, I don’t like it when something is 'not right' and since this is a hobby I have the luxury of fiddling around to improve the machine. I ordered a few left hand hubs since, with a standard taper, they are relatively inexpensive.

I just started to look closely at this machine, and careful disassembly and inspection will have to wait until I am finished rescraping my milling machine. I don’t want both machines down at the same time.

Just to be clear - I did remove what I believe to be the 'dust cap' and rather than seeing set-in bearings, I see what looks like a white metal sleeve or cap that I do not see any way to remove (pictures attached showing the components lined up). This sounds different that what you describe projectnut. Once I finish up my other project, I will take off the spindle assembly, have a closer look, and let you know what I find.

 

[ljwillis]

Hi All,

Another Sanford MG owner here, just joined the forum and have only had the machine for a couple of weeks and am cleaning it up and figuring out what needs repair (which seems to be everything...)
Mine has a serial number starting "168" so I guess 1968 is year of manufacture. Found it here in NJ for ~$700 which was arguably too much money but I like the design and size of this machine despite its poor condition.

I posted in the machine rebuilding/scraping thread asking if anyone knew where to find a 6 2/3 TPI elevation leadscrew (square thread profile at that.) Does everyone else have 3:1 gearing on the downfeed and 6 2/3tpi screw?

I would also love to hear any info on the spindle design. I haven't taken it apart yet because it seems to be the only thing that's OK on my machine, but I'm concerned about a sound I hear when I turn it by hand and anticipate needing to service it. Runout is nonexistent and it doesn't get too warm, but it doesn't spin as freely as I would expect it should. That makes me fear that someone may have increased the preload to try to make up for bearing wear or somehow otherwise messed things up.
I take it that the entire casting is the spindle housing? There's a small piece that I would hope is only a dust cover on the back of the spindle held by two screws. That's not retaining the bearings is it?

Also, what does this oil cup lubricate? I would think the vertical ways, but it's over the spindle and proximal to the leadnut.

 

[ljwillis]

Also, was there anything special about the original motors on these? I was skeptical about a single phase motor on a surface grinder, and the worn out Sears & Roebuck replacement motor the previous owner put on mine certainly reinforces that bias. I've got it apart and am replacing the bearings, but ultimately I'll be upgrading or replacing.
Is everyone still running single phase, or did anyone switch to 3-phase and if so did you see a meaningful improvement in vibration/surface finish?

 

[projectnut]

Post #22 shows the top of the column of my machine with the oilers. As for motors Sanford offered their earlier machines either with a factory supplied motor or a customer supplied motor. If I recall correctly mine has a single phase 110/220V 1/2 hp Hoover brand motor. Later machines could be ordered with a 110/220V single phase motor, aa 220/440 3 phase motor, a 110V DC motor, or a specialty motor requested by the customer. With the proper wheel and technique I can achieve a mirror image on most materials.

I'm not sure of the purpose of the oil port shown in the picture. I don't believe my machine has that port. I'm currently out of town, but will check when I return home. It looks as though it might be directly over the Y axis feed screw end bearing.

There are a number of other threads that can be searched using the words: Sanford MG.

 

[benmychree]

I cannot imagine that oil port would serve the spindle, hidden from view as it is, easily neglected, but then again, the surface grinder that I ran in my apprenticeship had the oiler fairly well hidden behind the side of the wheel guard; while replacing and scraping in the new plain bearing spindle bearing, I asked the foreman about mounting the drip feed lubricator in a higher and more prominent location; he was rather negative regarding the suggestion until I told him that no journeyman who showed me how to run it had shown me the oil cup, and I had never filled it for some time after I was regularly operating it; with that, I made a bracket to mount the oil cup in a highly visable location, with an brass engraved plate with instructions as to what oil to use. This was 1 16 X 72" Mattison surface grinder with 20" wheel and 15 HP at one's command.

 

[ljwillis]

Post #22 shows the top of the column of my machine with the oilers. As for motors Sanford offered their earlier machines either with a factory supplied motor or a customer supplied motor. If I recall correctly mine has a single phase 110/220V 1/2 hp Hoover brand motor. Later machines could be ordered with a 110/220V single phase motor, aa 220/440 3 phase motor, a 110V DC motor, or a specialty motor requested by the customer. With the proper wheel and technique I can achieve a mirror image on most materials.

I'm not sure of the purpose of the oil port shown in the picture. I don't believe my machine has that port. I'm currently out of town, but will check when I return home. It looks as though it might be directly over the Y axis feed screw end bearing.

There are a number of other threads that can be searched using the words: Sanford MG.

I would appreciate you taking a look when you get home, thanks. My y-axis doesn't have an end bearing, it is supported by the nut. The y-axis/crossfeed nut oiler is under the table, which is rather absurd.
It could be for the downfeed nut, but it's off center so that would imply I would find an oil groove in the underside of the nut block and a hole in the nut. I will investigate.
I would have hoped they'd have made provisions for lubricating the vertical ways without removing the cover - that may explain the modification on your machine. It's possible it does both, but I haven't found oil running out anywhere. Then again, one of the oil holes on the longitudinal table didn't daylight in the oil groove, I had to drill it out. I can only imagine that was a manufacturing error, though all of the oil cups were packed with grease and grit and needed to be blasted free with compressed air.

Regarding the motor, that's good to know that a good finish can be had with a single phase motor. It shouldn't be a problem with good bearings and a well-balanced motor since it's a belt drive. However, is there any kind of rubber washer under the motor acting to insulate the motor vibration from the mount casting? My motor's bearings are shot, for sure, but I was measuring 20um vibration amplitude of the spindle housing with an indicator mounted on the crossfeed table pointed up and resting on the wheel guard. That same measurement on the Harig 618 I've used at work was more like 2-4um. Despite that vibration I managed a decent finish off the Sanford but not without some work changing feed rate in spark-out to cancel the chatter.

 

[ljwillis]

I cannot imagine that oil port would serve the spindle, hidden from view as it is, easily neglected, but then again, the surface grinder that I ran in my apprenticeship had the oiler fairly well hidden behind the side of the wheel guard; while replacing and scraping in the new plain bearing spindle bearing, I asked the foreman about mounting the drip feed lubricator in a higher and more prominent location; he was rather negative regarding the suggestion until I told him that no journeyman who showed me how to run it had shown me the oil cup, and I had never filled it for some time after I was regularly operating it; with that, I made a bracket to mount the oil cup in a highly visable location, with an brass engraved plate with instructions as to what oil to use. This was 1 16 X 72" Mattison surface grinder with 20" wheel and 15 HP at one's command.

It's incredible what some folks will do when designing machines - I wouldn't want to suggest that perhaps Mattison knew it wouldn't get oiled and they'd have plenty of business rebuilding spindles, but it's also hard to believe that such an important oil cup would be hidden away. On the Sanford, the crossfeed nut oiler requires you to remove the table to access it! While in principle that means that the operators are regularly removing the table to clean and inspect in addition to lubricating, in practice it means the thing never gets oiled and the screw and nut show the wear to prove it, as do the longitudinal ways which were missing their oil cups altogether.