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]

Sanford MG-612 Surface Grinder

Pre-purchase Inspection

Prior to the purchase, I prepared a check list and some related materials to make sure I would not overlook anything in my inspection:

Items to bring:

• Flashlight
• Small metal bar (to test mag chuck)
• Oiler
• Shop rag
• moving blanket
• tarp (in case of rain)
• Small cardboard box (for nuts, bolts, etc. from dis-assembly)

Inspection checklist:

• Overall condition of machine
  • rust?
  • check condition of bed
  • electrical components in good condition?
  • check motor
  • check belt
  • check elevating screw condition, make sure it is lubricated
  • test elevation screw hand-wheel
  • remove table and inspect the ways and other components
  • make sure there is good lubrication and replace the table
  • make sure machine has been lubricated before testing hand-wheels
  • test all hand-wheels - full travel
  • test magnetic chuck using small metal bar (manual lever works OK, holding power is good)
  • inspect grinding wheel (OK to power up?)
  • power up - check for any vibration (hold hand on spindle to feel for vibration, listen for noise)

The most critical components to check are the condition of the ways, and the spindle. I could only perform visual inspection of the ways. I used a shop rag to wipe oil from the ways and look for any sign of scratches, gouges, or other mistreatment. Although the ways might have been scraped in when it was new, I could not see any sign of hand scraping (not surprising in a 60 year old machine). I did feel or hear any sign of vibration in the spindle. All three hand-wheels operated smoothly.

Bringing it home

The grinder was loaded (in pieces) onto my utility trailer with the exception of the table and the box of nuts. bolts, etc., which I placed on a moving blanket in the back of my car). Fortunately the weather was clear, but I squirted extra oil on the exposed ways just in case, for the 1-1/2 hour drive home. Everything was securely strapped down, of course, with multiple ratchet straps. The drive home was uneventful (I made couple of stops along the way, just to check to make sure the straps were secure).

Once I had it home the next step was to get it removed from the trailer. I did this using a Harbor Freight 2-ton shop crane (see pictures below - click on any picture for a larger view). Before attempting to lift the grinder, I removed the table (and magnetic chuck) and all of the hand-wheels - both to reduce weight and to prevent any accidental damage to the hand-wheels (usually the fist thing to break when things go south). I put lifting straps under the base and also under the vertical spindle support. It's tempting to try to just lift using the spindle arm, but I think this is a very bad idea. I also put heavy duty rope around the top of the vertical support arm and the lifting straps, to prevent the grinder from rotating when lifted. The grinder is very top heavy, and sideways tilting is always a danger when moving the grinder (especially with the "counter-weight" of the table and magnetic chuck removed). The shop crane lifted the grinder easily, and it was also fairly easy to move the crane and grinder around my garage, so I could set the grinder down on a furniture dolly.

Note that I put cardboard over the table ways to protect them (after applying generous amounts of oil). Similarly, the table (after oiling the ways), was placed on a piece of heavy cardboard to protect he ways.

Next step: Moving the grinder to my basement!

Getting the Grinder into the Basement

Note, see the album for more pictures.

In order to get the grinder from my garage to the basement, I have to move it to the back of the house, and down a small hill to a patio entrance (house is split level in the back, so I have a "ground floor" entrance there). From the patio entrance, it's a fairly easy move through a family room to my basement workshop. The Sanford MG is too heavy to move in one piece with the equipment I have, so the plan is to take it apart and move the pieces. I'll also have to move my shop crane temporarily from the garage to basement, to help with the re-assembly.

Table: The table and magnet just lift off (heavy, but one person can lift them); from there I put them on a furniture dolly (sitting on a piece of oil soaked cardboard to protect the ways) and dragged them into the basement.

Hand-wheels: I removed all of the hand-wheels for two reasons. First, I wanted to re-paint two of them, and make some fixes to the third, and second, I didn't want to risk breaking them if something tipped over during the move. I also removed the vertical travel indicator (too easy to snag on something), and cleaned that up as well.

Saddle: After removing the two screws that hold the saddle to the screw, the saddle lifts off easily. Again, the saddle was placed on a cardboard surface to protect the ways.

Wheel and wheel cover: These were easily removed - not so much as to reduce weight, as to protect against breakage. The bare spindle was covered with plastic and tape to protect it.

Column: Before attempting to remove the column, I removed the column cover. This allowed me to inspect the gearing and ways, and also opened up the top of the column so I could use a lifting strap on it. The column is held on by six large socket head screws. Before removing the screws, I attached a lifting strap to my shop crane, and cranked up the crane just enough to apply some upward lift. I used a breaker bar, extension, and 3/8" hex socket to loosen and remove the screws (those screws were in tight, I could not loosen them with just a socket wrench). Before attempting to remove the screws, I applied some penetrating oil - not sure if it made a difference or not.

After removing the column, I found that it had been shimmed on one side. I plan to keep the shims and re-use them when I re-assemble the grinder. The column is estimated to weigh around 95 pounds; I plan to lower it onto a hand truck, strap it on, and move it that way.

Basement at Last!

With the grinder base loaded onto a (1,000 lb. capacity) furniture dolly (with a temporary handle added), I was able to drag it into my basement. Dragging it through the grass was no fun, and at one point the grinder started to slide off the dolly; if I were going to do it again I would strap it to the dolly. I removed the folding legs and extendable boom from my shop crane to lighten it, and got that into the basement with out too much trouble. With the shop crane back together, it was fairly easy to lift the base onto the stand. I used two lifting straps to lift the base (to prevent tipping while lifting), and lowered the base onto temporary wooden blocks on the stand so I could remove the straps. The base lifted easily off the wooden blocks with a small pry bar.

With the column strapped to a hand truck, I was able to move it easily into the basement. The shop crane was a bit of a tight fit, with the legs barely fitting around the stand and crane boom just clearing the ceiling. Before fastening down the column, I cleaned up the mating surfaces, replaced the shims, and applied a film of white lithium grease (mostly because that is what I had handy). I was able to get the column into place and get all six bolts in so I could remove the crane. I tightened the bolts with a socket wrench first, and then finished up with a breaker bar to make sure they were good and tight.

MG-612 Surface Grinder Specifications

Below are the specifications as taken from the original Sanford product brochure. This does not guarantee that your Sanford MG-612 will have the same specifications. Note that the specifications are for a 1/2 HP motor, whereas mine has a 1 HP motor (probably an upgrade by one of it's previous owners).

Here are some before and after pictures of the wheels:

Hand-wheel shaft locks

[7/22/1018]

The shaft locks are very simple 1/4-20 "bent screws" (see photo). The ends of the screw that contact the shaft are quite rough, with no finish at all. I have no idea whether these screws are original to the machine (although they look very much like the ones in this brochure). I noticed when I removed the hand-wheels that shafts had been slightly scored by these rough screws, so I ground the ends flat, and inserted a brass "cushion button" into each screw hole before replacing the locking screw (actually I "glued" the button to the end of the screw with grease, so it would stick while I inserted the locking screw).

The buttons were made from brass rod. I simple milled a 7/16" curve into the end of a brass rod, and then cut off the end about 3/16" in length. This is a bit of a stop-gap until I can come up with something better, but it should work fine for now.

Grinding Wheels, Basic Tools

After removing the wheel that came with my grinder, I found it a was a Radiac F322185; this is a 7" wheel new, but mine has been worn down to about 4.9". I was rather puzzled by the "gear" on the adapter, but I eventually found out that it is called a "gear-nut", and requires a special wrench to remove it (1-1/4-16LH threads, by the way) - Sopko refers to this as a "Glare gear assembly."

Two other tools that are required are a special thin-walled socket wrench to remove the (left hand) spindle nut (the hexagonal nut in the picture above left); the Sopko 35135 wrench is made for this, and also works as a pin spanner for Sopko standard adapters. The second tool is a wheel puller - this screws into the adapter after the spindle nut is removed; the central bolt is then tightened to pop the adapter off the spindle.

Lubrication

As I have not been able to locate a decent manual for the Sanford, I looked at the manual for the Grizzly G5963 surface grinder, which has a couple of pages on lubrication, as well as some other useful info : http://cdn0.grizzly.com/manuals/g5963_m.pdf

Here is a summary of lubrication recommendations from that manual:

• rack and pinion, Z-axis gears : medium coat of NLGI#2 grease or equivalent
• ways : ISO 68 way oil (note this is way oil, not just plain machine oil

Setup and Improvements

The machine needed a general cleanup. In addition, the mag chuck had some rust, and the table clamps were kind of junky. I took the mag chuck off the table and cleaned it up with some WD-40 and a scotch-brite pad. I made a new set of chuck clamps, mounted and dressed a new wheel, and ground in the chuck.

The next job I did was to run a Five Block Test. For this test, 5 small (about 1" square) CRS blocks were ground flat and parallel on two sides. Then the blocks were placed on the mag chuck in this pattern (no pictures on this, unfortunately):

1 2

3

4 5

The blocks were then ground again, and then measured to see how closely they matched. Ideally, if the mag chuck is ground perfectly flat, and the blocks are ground perfectly, they will all have identical thickness. In my case the blocks were all within a few tenths of each other, except for block number 1 which was off by 4 tenths. More than acceptable to me at this stage of my learning.

The next job I did was to grind in a stainless steel ring I use for tramming my mill. In use, the ring is laid flat on the mill table, and the flat surface it provides allows me to move a dial test indicator in a circle to tram the mill. I have no idea what this ring was made/used for originally - just something I picked up somewhere along the way.

Below are pictures of the ring (both sides, about 7" diameter) sitting on my surface plate. Before grinding I measured both sides of the ring to see how far the surface deviated from flatness; the numbers on the ring are deviations in tenths from an arbitrary zero setting. The measurements show that the surface is a bit dished in the center by almost 0.001". I had made simialr measurements previously and used those measurements to compensate when tramming, but this is not very convenient.

Harvey Butterfly LG8-12 Surface Grinder

The Harvey Butterfly LG-812 surface grinder is reported to be a copy of the Sanford MG-612 surface grinder (link to brief history of Harvey Manufacturing Co.) Here are some pictures of the LG8-12 from an ebay sale:

Purchase Information

If you are buying used machinery, you of course would like to know what to pay as a fair price. Toward that end, I have started to collect information on this, which I am including in the spreadsheet below. If you would like to add your Sanford or Harvey purchase information to the list, you can email me at the address below, or you can just add your information to this post on Hobby Machinist : https://www.hobby-machinist.com/threads/looking-for-sanford-mg-612-surface-grinder-owners.69888/#post-589813

Please include the following in your email (or post comment on Hobby Machinist):

• Date purchased
• Purchase price
• Serial number
• Spindle taper
• Spindle nut thread - RH or LH?
• Additional items included in purchase price
• Other relevant details - condition, missing/broken parts, etc.

Note: The references and links below are for information specific to Sanford MG and Harvey LG surface grinders. For information on surface grinders generally see this page:

https://sites.google.com/site/lagadoacademy/machining---lathes-mills-etc/my-surface-grinder---2

References

• Sanford Literature - A collection of brochures, manual, quotes, etc. from the Sanford Manufacturing Corp.
• Sanford Miniature "SG" Surface Grinder : This link discusses the Sanford SG model (mine is the larger MG model), but includes good information on Sanford surface grinders in general. Includes links to manuals and brochures.
• Sanford scans : "Schematics of the re-design I did on the electrics for driving the electro-magnetic chuck on mine. Scannings of flyers, the manual, and quote sheets from Sanford before they stopped responding to the world.
• Sanford Corporation timeline : "In 1959, Sanford Manufacturing Corp. was manufacturing industrial grinders at 1026 Commerce Ave., Union, NJ. They specialized in smaller well-built grinders." Includes an advertisement for the Sanford MG, as well as a little bit of historical information.

Tutorials (Videos)

• Rebuild by Bruno M.:
  • Sanford Model Mg Surface Grinder Rebuild -PT1 - Bruno M. - Cleaning, painting, re-assembly.
  • Sanford Model Mg Surface Grinder Rebuild -PT2 - Bruno M. - Mounting motor, mag chuck, electrical.
  • Sanford Model Mg Surface Grinder Rebuild -PT3 - Bruno M. - Wheel misting addition, wheel dressing, grinding in magnetic chuck.
• Rebuild by R. Steven Lang:
  • Sanford MG Surface Grinder Part 1
  • Sanford MG Surface Grinder Part 2
  • Sanford MG Surface Grinder Part 3 Making Sparks
• Sanford Grinder : A Sanford MG being run for a prospective buyer.

Links to Forum Discussions

• Hobby-Machinist
  • Looking for Sanford MG-612 Surface Grinder owners : My post hoping to find more information on the Sanford MG. Lots of good pictures and information on this post.
  • New Sanford Mg 6x12 Surface Grinder : Nice post on new grinder with lots of pictures.
  • Sanford Surface Grinder Question : Brief discussion; some good pictures.
• Home Shop Machinist
  • Sanford MG, cleanup and assembly : Lost of pictures; nice addition of leveling feet to the cabinet.
• Practical Machinist
  • Grinding chatter issues with Sanford MG612 Surface Grinder : Brief description of Sanford MG and discussion of reducing chatter.
  • Sanford MG-612 Surface Grinder : Discussion among several Sanford owners, some pictures.
  • Sanford MG bearing : Brief discussion of bearings. Interesting note that "MicroMech WMSA (= rebranded sanford MG612 w/ a slow power feed added)"

Parts and Supplies

Note: Sanford made changes in production of the MG612 during the course of their business. Some parts may be interchangeable among all versions, others may not. Do not assume that parts listed below will fit your grinder - verify measurements, etc. before purchase.

• Bearings
  • 2 Angular Contact Bearing 7205B 25x52x15 : "Reviewer: John From Wallingford from Wallingford CT : I use this in a Sanford Model MG612 surface grinder. The grinder calls for high precision ABEC class 7 bearings costing in the neighborhood of $300.00 for the set. But in a non production shop these are just perfect and I can still grind to withing 0.0005"
  • Forum post : "I mentioned in an earlier post I didn't think the spindle bearings were precision in that they were marked 205SZZ. When I went to look them up I found that there is a 205 series made by MRC that is considered precision. I can't remember the full number, but new from most bearing suppliers they cost around $150.00 each. I'm not planning on changing them out at this point, but I did see they are available from Locate Ball Bearings for $108.00, and free shipping."
• Wheel adapters, related tools, etc.
  • Sopko : "Our manufactured line is extensive and includes a wide array of stocked products ranging from wheel adapters for both large and small surface grinders to ID grinding quills ... We make and stock hundreds of Flat Belt and Poly-Vee belt ... and motor pulleys. Tool and Cutter Grinder users will find adapters to fit older Cincinnati No. 1 and No. 2 grinders as well a large selection of wheel-pack adapters for Walter Helitronic, ANCA, Huffman, Strausak and Schneeberger CNC machines. Our manufactured line of accessories include, Glare gear nuts, flanges with diameters ranging from 1-1/2"to 8", spacers, spindle nuts, wrenches, truing and balancing arbors, pullers, balancing stands, and a selection of innovative double-taper quills designed to convert internal grinding spindles for external grinding applications.