Sanford SG

[Mheaton92]

I am in the process of tearing down this machine, and I would like to make a public service announcement. THERE IS A SPECIAL PLACE IN HELL FOR PEOPLE WHO PAINT OVER HARDWARE! All jokes aside I am having some buyers' remorse, this machine is not in the best of shape. Some of the ways have ridges and the slope in the handwheels is bad. I really should have not bought it since the price wouldnt go down. But you live and learn I guess. I am going to do a full rebuild and replace everything that needs it, what is the point of having a machine shop if not to make parts you cant buy. I found this schematic for rewiring and will order all the parts. The grinder seems way to small for the things I want to do so I may try to rebuild and sell, we will see.

 

[Blackfly]

THERE IS A SPECIAL PLACE IN HELL FOR PEOPLE WHO PAINT OVER HARDWARE!

I feel like I've heard that somewhere recently, lol.
I know you've already found it, but for the others, I just did a Youtube video on rewiring the chuck. From there, you can find part 1, the teardown, and I just finished putting it all back together and will get part 3 (rebuilding the vertical adjustment) up in the coming days.
I got a replacement flat belt from McMaster, 17"x1/2"

 

[Mheaton92]

I feel like I've heard that somewhere recently, lol.
I know you've already found it, but for the others, I just did a Youtube video on rewiring the chuck. From there, you can find part 1, the teardown, and I just finished putting it all back together and will get part 3 (rebuilding the vertical adjustment) up in the coming days.
I got a replacement flat belt from McMaster, 17"x1/2"

Ha When I heard you say that I laughed, My wife was sitting at the table behind me and she also laughed beause I just told her something along the same lines (but with more bad language) the night before. The series so far is awesome! Do you plan on remaking some lead screws? I just got on the computer to order material because the shaft for the Z is really worn and the Z lead screw is also really worn, just like yours. Your machine looks like it is in much better shape than the one I got, my ways didnt show any flaking and pretty much all have ridges. I will take more pictures. Also when you put the Y back together did you add the thrust bearings? Mine did not have any.

 

[projectnut]

Yea the motor is 100% a 110 AC motor, I need to find a replacement start capacitor for it because from the reading I have done it can cause all types of issues. Why do you think it has been converted to a V-belt, it seems to be a flat belt that is really frayed?

V belts are much easier to keep on track than a flat belt. The flat belt needs a crowned roller and the motor needs to be shimmed to keep the belt tracking properly. Also over time flat belts have a tendency to stretch which lessens the power transfer to the spindle. All of their larger machines started with the V belt. The later model SG's also came with a V belt. The company stopped providing replacement flat belts sometime in the early 1950's and offered a kit to change to the V belt.

I believe the Sanford SG is about the smallest surface grinder built for professional shops. There seems to be quite a demand for them among knife makers. If you do restore it to original condition it shouldn't be to hard to recoup your money. While I have no idea what you paid for it a working SG in good condition will easily bring $1,000.00

Personally I have a 6"x 12" Sanford MG. It came in either the 6"x 12" configuration or a 6" x 18" configuration. They are the next step up size wise in the Sanford line. Here are a few pictures of my MG. Note this is the same as it looked when I bought it about 10 years ago. It didn't need anything rebuilt, and hardly anything needed to be cleaned

 

[Mheaton92]

V belts are much easier to keep on track than a flat belt. The flat belt needs a crowned roller and the motor needs to be shimmed to keep the belt tracking properly. Also over time flat belts have a tendency to stretch which lessens the power transfer to the spindle. All of their larger machines started with the V belt. The later model SG's also came with a V belt. The company stopped providing replacement flat belts sometime in the early 1950's and offered a kit to change to the V belt.

I believe the Sanford SG is about the smallest surface grinder built for professional shops. There seems to be quite a demand for them among knife makers. If you do restore it to original condition it shouldn't be to hard to recoup your money. While I have no idea what you paid for it a working SG in good condition will easily bring $1,000.00

Personally I have a 6"x 12" Sanford MG. It came in either the 6"x 12" configuration or a 6" x 18" configuration. They are the next step up size wise in the Sanford line. Here are a few pictures of my MG. Note this is the same as it looked when I bought it about 10 years ago. It didn't need anything rebuilt, and hardly anything needed to be cleaned

That is a great Idea, I will convert it over to a v-belt, a 6x12 is really the size I would like to get. Side note your shop looks awesome and I am envious!

 

[Mheaton92]

So, a update on this machine. It is in awful shape, I just replaced all the brass bushings and the rack and spur gear. I am struggling with the lead screws because they do not look like acme threads. They look like square 90-degree threads? The Y lead screw does not look that worn, but when it is in the half nut I can pull it back and forth. The Z lead screw is visibly worn. I had planned to remake both, but I am having trouble figuring them out. From what I can tell they should be 5/8-10 but they do not look to have the 29-degree angle. Does anyone think it is possible that someone remade them as square threads? If they did would a square thread still thread into a acme half nut? I will add pictures when I get a chance.

 

[projectnut]

They look to me like a Square thread. A Square thread is similar to an acme, but rather than a 29* taper the taper is 0*. They were often used in high precision machinery

 

[ddickey]

You need to replace the nuts too so just get the acme screws.