Sanford SG-48 Surface Grinder

[unclemoak]

I have a small machine shop in my basement and have always been intrigued by surface grinders. This one popped up for sale on a machinist FB page, so I struck a deal with the seller and braved the blizzard like conditions here in NE Wisconsin this morning to pick it up.

I honestly doing know jack about surface grinder or much about this particular model in general, but it's compact, benchtop size is nice for my small shop.

Quite a few cars in the ditch on the way down to Milwaukee. Surprisingly I didn't have too much trouble even with my 2wd truck. It was slow going, but I made it without incident, only to get stuck in my driveway when I got home.

As you can see with the spray paint can for size reference, this is a pretty small machine.

I put some way oil in all the oilers and everything seems to rotate and move freely, so it should be a pretty straight forward job to get this cleaned up and back into service.

 

[matt_i]

My 0.01 is...be careful of the wheels. You don't want to blow one up. I'd ditch that old wheel asap. The surface finish will be largely controlled by the condition of the spindle bearings...which could be great or need work. They live in a gritty environment so really any grinding equipment is slowing wearing itself out in general terms. Also I would be careful of the downfeed, 0.001" is a large cut. Most of them use a magnetic chuck for workholding. A diamond dresser point is also going to be important. I can't help you a lot with wheel selection. I have a harig 612 which I've used a bit but only with the wheel that came on it. You can do really pretty work with it, removing the tool marks from milling or taking care of hardened material.

 

[KMScott]

Matt covered most of the items, but when replacing wheel the threads to hold on your wheel are left handed. If you did not get the spanner wrench then you need to make one. Defiantly add the wheel guard if anything to keep the grit from flying everywhere. The diamond Matt mentioned sharpens the wheel using the cross slide and the diamond should be used on the side of the wheel around 7 o'clock so the wheel does not climb into the diamond. Have fun with it and let's hope if gives you a good finish.

 

[OccupantRJ]

Get a pink wheel. It should do what you want. Cute little machine, just right for model builders.
Not all grinders have a left hand thread on the spindle. Depends on the rotation of the wheel.

 

[MShaw]

I used one of those many years ago. In good condition they are a very accurate machine and will do a lot of smaller work.

You will find 60 grit wheels good for roughing and general work, 80 to 120 grit for finishing.

The code is something like 32A60-JVBE where 32 is the manufacturer's code for the grit used, A is the type of grit (A for aluminum oxide-C for silicon carbide) 60 is the grit size (larger number = finer grit) The letters are the structure (openness) and the hardness.

Silicon carbide is usually used on very hard steels and carbides or non-ferrous materials.

Hope this helps.

 

[unclemoak]

I used one of those many years ago. In good condition they are a very accurate machine and will do a lot of smaller work.

You will find 60 grit wheels good for roughing and general work, 80 to 120 grit for finishing.

The code is something like 32A60-JVBE where 32 is the manufacturer's code for the grit used, A is the type of grit (A for aluminum oxide-C for silicon carbide) 60 is the grit size (larger number = finer grit) The letters are the structure (openness) and the hardness.

Silicon carbide is usually used on very hard steels and carbides or non-ferrous materials.

Hope this helps.

Thanks! As I work on getting it fixed up, I'll have to start looking for wheels.

 

[unclemoak]

I couldn't resist the urge to plug it in and check the motor if it worked. I'm sensing the belt is shot from all the years of sitting.

 

[bimmer1980]

What did you end up paying for it?

I saw one of these pop up on craigslist for $100 locally, but I was too slow on contacting the guy.....

 

[unclemoak]

What did you end up paying for it?

I saw one of these pop up on craigslist for $100 locally, but I was too slow on contacting the guy.....

$100. I thought that was pretty fair.

I think by the time it's stripped down, fixed up, and a chuck put on it, it'll be worth closer to the $750 mark.

 

[jamesly]

Matt covered most of the items, but when replacing wheel the threads to hold on your wheel are left handed. If you did not get the spanner wrench then you need to make one. Defiantly add the wheel guard if anything to keep the grit from flying everywhere. The diamond Matt mentioned sharpens the wheel using the cross slide and the diamond should be used on the side of the wheel around 7 o'clock so the wheel does not climb into the diamond. Have fun with it and let's hope if gives you a good finish.

All good info here. Very cool. Good Score. That brought back memories. You can get the most fantastic finishes with a Surface Grinder if you a very,very patient. You can dress radiuses and angles too. If at all possible get a dust collector and always wear a mask of some type...

My first shop job after NTMA school back in the 80's was in a tool and die shop where we made injection molds for Integrated Circuits among other things. EDM's and Surface Grinders working A-2 and D-2 Steel molds.

That shop was EDM's and surface grinders and the tolerances were ten thousandths. The guys that trained me were magicians, and they would grind all day at very slow feeds, dressing constantly to get to .00015.

In the end I didn't have the focus for surface grinding like that all day. But I appreciated the work 110%. I ruined a few expensive parts learning, just barely kissing the part with a wheel that wasn't dressed properly.. But I made some really neat parts, and cool stuff for myself too.

I didn't realize some of you guys had Surface Grinders in your shops.. too cool..

 

[Faust]

What did you end up paying for it?

I saw one of these pop up on craigslist for $100 locally, but I was too slow on contacting the guy.....

I got mine for $10.00 at auction. Few problems. Cover for the wheel is completely gone. Power supply for chuck is toast, rusted, broke vacuum tubes, etc. I would greatly appreciate a picture of the wheel cover mounted, I will probably have to make one. Can anyone supply a diagram of the power supply? If not, I will probably mount a small permanent magnet chuck I have.