Surface grinders question

Good accuracy, and the ability to machine things too hard to cut normally.

Pack one up for me! As long as all the parts are there, and a reasonable amount of work will restore it to good accuracy, I'd love to have one.

If this is possible, give me a quick email.

LLoyd

A surface grinder is something you don't necessarily need very often, but when you need it, there isn't much else that works... It is also a machine that doesn't cost much to support (tooling, etc.) 50 to 100 bucks worth of wheels and a diamond dresser will cover just about anything that comes along.

Its principal use is in getting a very good finish on flat surfaces. You can also use it for forming dies out of HSS and other things too hard to cut with the mill.

Jerry

Jerry

Buy one to find it out! Sharpening / making tools.

Nick

Maybe I should give him a lowball offer for the lot and resell the ones I don't want.

Because it's only $300! Randy

Do you need any help transporting them?

I'm less than 300 miles from FW.

==================== It all depends on what size/type of things you make in your shop, and the types of tooling you use.

Some people would use one on almost a daily basis while others would never use one.

If you have been in machining for a while and can't think of a complelling reason why *YOUR* shop needs one, then you don't.

That being said, I would love to have one just to make 60 degree and acme HS thread tools.

Unka' George (George McDuffee) .............................. Only in Britain could it be thought a defect to be "too clever by half." The probability is that too many people are too stupid by three-quarters.

John Major (b. 1943), British Conservative politician, prime minister. Quoted in: Observer (London, 7 July 1991).

LOL Well, that's my gut reaction, but a crowded shop compels moderation

Because you don't have one!!

And with a cup wheel..its handy as hell for grinding lathe and shaper bits of all shapes and sizes

Gunner

Rule #35 "That which does not kill you, has made a huge tactical error"

And if you stick on a cut off wheel..they make a pretty good abrasive chop saw for short(er) lengths.

Gunner

Rule #35 "That which does not kill you, has made a huge tactical error"

But make sure that you pick up the one with the automated vertical feed :-)

Mark Rand RTFM

My most frequent use of surface grinder was to 'true up' parts after heat treatment. Almost everything warps to some extent when heat treated. With an indexer, it can also be used to accurately reduce shanks of twist drills, taps, etc. (with correct size collets of course)

Also frequently used one to remove slight 'cupping' or 'doming' which happens often when parting off on a lathe.

George, What sort of fixture would you use to hold the bit to grind a threading tool? I've been thinking about this for the school shop but haven't come up with a simple one. ...lew...

================ Far from original with me but I can't find the reference. If I come across it I will scan and send you a copy.

Basically a simple mill project.

Think of an upside down T made out of 1 X 2 steel. The vertical part of the T has 3 slots milled in it. 1 slot is vertical and is for grinding the end clearance. The other two slots are angled so that the included angle of the tool is correct. You only need one vertical slot, so you can put a different angles on the other side of the vertical piece, say 30 degrees for 60 degree tool and

14_1/2 for 29 degree tool. The base of the vertical part of the T is milled at the desired clearance angle, c. 10 degrees, and while at this angle is drilled and tapped. The base is drilled and counter bored to same c/c distance. [use red loctite when assembling]

In use, use a belt sander with a rough belt to remove most of the material, then the rough blank is clamped in the fixture in one of the angle slots and the fixture placed on the surface grinder [magnetic table works well] Grind about to center/half-way of tool blank, flip blank over to other angle slot and repeat. Put blank in vertical slot and grind tip end to specified flat, generally 1/8 pitch [unf/unc] or to acme gage. You can drill and tap some holes in the vertical piece for a clamp or rig one of the lever action over the center clamps.

Included angle and clearance angles are controlled by the fixture so the more accurately this is milled, the more accurate the tool will be. If you have a sine bar, use that and an indicator, and don't rely on the vise graduations.

Very quick to use, and when you take just that one whisker too much of the end of the acme tool, it no big deal to reset and take a little off the sides and try again.

With rough belt-sanded blanks (or salvage tools) this a very quick operation, even for acme tools. I have not made one, but no reason you couldn't make a fixture for buttress thread tools, possibly the front for one hand/direction and the back for the other hand/direction. Another variation would be a 60 degree and horizontal slot to generate tools to thread up to a shoulder. Again use front/back for different hand.

For honing the finish ground tools, use a blue nylon bristle [fine] abrasive brush in a drill press at slow speed. This removes material quicker than you think so don't overhone. One quick pass is generally all it takes.

This is a simple project, and your students may like to build one for their own use. Reinforces the idea of using tools to make tools. Minimal materials required -- (1) 1 X 2 X 3 and (1) 1 X 2 X 6 pieces of steel [for up to 3/8 bits - bigger bits should most likely have a bigger fixture], (2) SHCS to hold vertical part to base, a 2 inch piece of key stock and 2 or 3 shcs for a clamp.

Unka' George (George McDuffee) .............................. Only in Britain could it be thought a defect to be "too clever by half." The probability is that too many people are too stupid by three-quarters.

John Major (b. 1943), British Conservative politician, prime minister. Quoted in: Observer (London, 7 July 1991).

If you are talking about the guy in Haltom City, those are tool post grinders not surface grinders. Use for sharpening end mills and such.

Worth the cash for sure but NOT surface grinders.

Why? The table moves side to side

Gunner

Rule #35 "That which does not kill you, has made a huge tactical error"

Well ... what I did was to make a wedge using a small sine bar and the shaper to half of the Acme thread angle (14.5 degrees), and put that across the bottom of a small vise to select the tip angle of the tool bit. (It takes two setups to get both sides).

And -- I mounted the vise on a sine plate, to grind the side relief angles (different for each side -- and I had to remember that I was grinding a tool for an internal thread, and reverse the clearance angles). With this setup, I was able to grind a tool just right for cutting the internal Acme thread I needed to fix a friend's log splitter.

The final grind setup was for the tip relief (without the sine plate, this time), and lowering the wheel one or two thousandths at a pass until I got the tip width right for the Acme threading gauge.

There are probably other ways, but this is what worked for me, and I keep that little 14.5 degree angle aluminum in my box of cheap Chinese gauge blocks -- not with the good B&S Jo block set.

Enjoy, DoN.