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New to me flick grinder, have questions.

jonok

Cast Iron
Joined
Sep 18, 2013
Location
Michigan
I got this WMC surface grinder as a toss in with mill I bought recently.

It seems to work reasonably well with the exception of a magnetic starter that doesn't like to turn off every time. I've adjusted it to the lowest numeric setting with no consistent improvement. Are these just throwaway starters, or is it worth doing something to try and fix it?

Also, is there a suggestion as to a good starting point for a new wheel for general purpose ferrous/stainless use?

Thanks,

Jimimage.jpgimage.jpgimage.jpg
 
Looks like gravity may be the problem... parts fall off chuck when you turn mag off.

Simple small machine but in good shape all you need for much work.

Start wheel perhaps a 46 I through K... I prefer starting out with a name brand white aluminum oxide wheel
should add table stops, yes you can just drop a parallel in front for a stop. . be sure the oil pots are full..or if ball way the racks and balls are clean. Put a dust box on the go side that catches and reflects the dust to away side where it may fall into a bucket. Grinder may fill the room with fine dust so a good idea to wear a mask. *You can make a simple fixture to end sharpen end mills...

SS can be a bugger to grind with any wheel

Be sure wheel mounts are bug free, wheels ring, are correct RPM, have blotters.

Place block-ins on the go side almost as tall as the part to be ground touching near the top edge because the wheel can tip a tall part. *If you are at north east Detroit area send me a private message.
Buck
 
Yeah, looking at the pictures, it must have been made in Australia, sorry.

Has a single shot oiler which seems to work and has some oil in it.
 
If you are calling a magnetic hold down a mag starter for a motor then I am confused. If the motor won't stop when you hit the red stop button then stop diddling with the drop out current control and replace the stop button switch, it isn't breaking the circuit. Look at the stop button switch where the wires connect to see if it is caked with residue or falling apart.
 
If you are calling a magnetic hold down a mag starter for a motor then I am confused. If the motor won't stop when you hit the red stop button then stop diddling with the drop out current control and replace the stop button switch, it isn't breaking the circuit. Look at the stop button switch where the wires connect to see if it is caked with residue or falling apart.

Nope, I'm calling the magnetic start/stop contactor I included an upside down picture of, the starter. The motor is 240 single phase, and has a centrifugal secondary. All of the motor stuff works fine, it's just the magnetic contactor that doesn't shut off all the time.

They look to be fairly expensive, and my poorly-worded question related to the advisability of attempting repair vs starting over with a new unit. The box isn't full of grinding dust, the buttons aren't broken, and the "off" low voltage points open without difficulty. So what's happening is that the actual relay does not seem to be opening all the time. It doesn't even always open immediately upon unplugging the grinder.

Thanks again
 
As Buck said, softer aluminum oxide wheels are easier to learn on and very versatile. It is easy for a noob to become a wheel collector of sorts. As an apprentice I was taught that a grinder hand can make most any wheel work for the one off small jobs. You aren't productive if you spend more time changing wheels than grinding. Start out with softer wheels and you may find later that you need a finer grit, possibly harder wheel for form grinding, such as fillet radii. I used to do aluminum castings with a 38A and WD40. Experience is more useful than wheels.
Before you mess with the chuck, grind a piece and check for flatness. That is what tells you that it's time to dress.
 
Has the remote/low voltage terminal got some dust/moth cocoon/"crap" in it? They seldom scorch or need any attention.

If it is onc of the contacts on a 3ph starter, sometimes you can just swap one of the hot wires from the scorched terminal, to the one that was not used.

If it actually only has 2 poles, then you can try dressing the contacts, subject to how badly it actually is burned.

To be a smart ass - yeah, gravity - as much as spring pressure, the magnetic part counts on gravity to break contact when interrupted, so if you are going to persist in using it upside down you'll at least have to invert the contactor set.

As someone else said, the numbered part you are screwing with just sets the drop out current for overload. set it back to a reasonable value to protect the motor and let it alone.

smt

PS if you only want one wheel to start and plan to throw SS in the mix, get a Radiac Ruby 46J wheel. Also good for tool steels. something of a waste for mild steel. But a good starting point. When you get good enough to dress your chuck, a 46 I or H 38A will be a reasonable starting point. If you can't grind smooth with a 46, then it is down to technique, not the wheel grit. However if you get into tool sharpening or spend a lot of time finishing surfaces for appearance, then a 60 J or I may be worth having on the shelf. When you get good with those wheels, you will probably be able to inform yourself whether an others are needed. It's going to be a long learning curve on a less than rigid hand fee grinder for surface work, though. :)
 
Took the contactor out, polished all the contacts I could get to and sprayed it full of qd electronic cleaner and shook it up real well.

Put it back together and it seems to be working fine now. (put the over current dial back where it was before).

Thanks everyone for the advice on wheels. The chuck seems to be pretty flat (about 0.0003 variance end to end with a few bumps here and there.

I've got some D2 chunks laying around and I am thinking that a couple sets of 1-2-3 blocks might be a good project to find out just what I don't know...
 
How did you determine that the chuck was flat? Inquiring minds want to know, since it is damn near impossible check the chuck itself on the machine.
 
I stoned the chuck which is still attached to the table, and then attached an indicator to the spindle and zeroed it at the center. I ran the table back and forth advancing .100 between passes.

I suspect that there is a fatal flaw in my methodology related th the fact that the table might not be flat, and the chuck is ground to account for any error, right?
 
I've got some D2 chunks laying around and I am thinking that a couple sets of 1-2-3 blocks might be a good project to find out just what I don't know...
Wow, you are a glutton for punishment. 1-2-3 blocks don't need to be D-2, and grinding D-2 sucks, to put it mildly. If you want to make 1-2-3 blocks to learn grinding, fine, but do yourself a favor and buy a chunk of A-2.

Dennis
 
I stoned the chuck which is still attached to the table, and then attached an indicator to the spindle and zeroed it at the center. I ran the table back and forth advancing .100 between passes.

I suspect that there is a fatal flaw in my methodology related th the fact that the table might not be flat, and the chuck is ground to account for any error, right?

The fatal flaw is that the ways may be worn, and the chuck just matches the curve worn into the ways. Now that you've determined that the surface of the chuck follows the ways, use a straightedge and feeler gauges on the chuck to confirm it's actually flat end to end.

Dennis
 
Might be good to buy a set of 123 blocks so you have some square block-ins that are good size.
Looks like for around $20 you can (ebay)have the same. I like no holes but each to his own.
Chucks most often are washed out on the back rail and at center so finding that is a plus for the grinder.. only .0003 I would be in the habit taking of a few more stone figure 8s in the high zones. get used to using the whole chuck with placing parts all about.
Might look see how simple to lift table and clean same..But don't take any chance to break something.

Chuck far out side...nearest you is the least wore part of the chuck so a good place to indicate and straight-bar check.

Good to have a new stone for only the chuck..6" or 8" name brand.. small stoning or poor shape stones make holes in a chuck. Oil hone, fine side, figure 8s with a good flat stone keeps the chuck flat IMHO... saves a lot of chuck grinding. 6 Inches Long x 2 Inches Wide x 1 Inch Thick 513965 - MSC

You can pick up a small plate at WoodCraft, and good to have a 1/2 x 5" x 10" (6x12?) ground steel plate with a few threaded holes for checking not-fussy parts and use for off set odd size/shape parts holding on the mill or grinder.
Woodcraft Search for surface plate

Grind the set off plate with checking for flat.. mark the low place and shim under that place so mag might not draw it down... grind like you are grinding a chuck.. wet and with a pause at ends if getting least bit warm..flip with check for spaces and shim under, then grind top. Yes stresses will come out so it will not be perfect off the best grinder (the first time you grind it)...so for non fussy parts. + or - .001 and more it is a handy plate.
 
For grinding the chuck.. when you are ready for such an important job.

Cash likes a 36 wheel and I a 46 but be careful because it is such a big part. Yes the 36 is safer and gives a good finish… Yes grind wet and take a pause after a few passes to feel to be sure no heat. If cool you can stop and then come back. You can’t do that with getting warm. Getting warm take a pause off part at the end of long travel, then a longer pause if needed.. Sill fear heat then only cross feed on the grind side and pass back over free of feed on the climb side..For the set pad be sure to do best job of de burring edges. After grind even a down going bevel will have a feather burr on the go-off side.

When you start out you may have a skip at the low place.. that is a pause...when you are grinding full across and still going that fast is often when you get in trouble.

Buck
 
So I stoned the chuck with the same Norton Fine Crystolon stone that I use on my mill table and my big drill press. 6x2x3/4 I think. Never used to sharpen knives. If this is inadequate I'd love to know before I screw something up.
 
That should be good for the mag chuck if it is flat. For mills and such I like to first run over with a name brand flat file then finish with the hone. Yes bargain files that come new out of flat.. like harbor's fright files belong in the dumpster.
 
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The best check for flatness is to check the result, not the chuck. Measuring on the machine as you did shows the relationship of the chuck to the spindle. That relationship was established by those same parts so will appear perfect.
Best to grind a piece close to chuck size, flipping it as needed to get it as flat as possible. The chuck will pull a piece to match the chuck so if possible start on double sided tape. When it is as flat as your machine can make it put it on 3 points on a surface plate and indicate the bottom side with a tenth indicator. This will give the best indication of chuck condition and the machines current ability.
 
_IF_ you manage "perfect chuck use" and shimming, the flatness or not of the result of TD's approach will be a reflection of the way condition of the machine, modified by your experience/good grinding practices level. For a newbie, it will be hard to separate out at least 3 factors. 1.) chuck flatness sucking work down, unwarping or not after grinding and release. 2.) way condition (the biggie) 3.) your experience in dressing the wheel and maintaining uniform grinding methods everywhere, manually, for hours on end. :)

To check way condition independently, shim a small surface plate (12 x 8, e.g.) on the chuck, indicate it everywhere, and map the results. Or use a scraped parallel fitters' straight edge, and map lengthwise, then cross wise.

This is easier for most than actually grinding a full chuck area workpiece flat and parallel on a hand feed machine. A good job of that for a new grinder hand could literally take all day depending on material starting condition and stress level.

smt
 
All good ideas given..

Another simple method is to first figure 8 with oil hone the whole chuck top. Next take a known straight part as long as your chuck, setting it at the close edge and look for daylight. You should be able to see .0005 error..0002 may look to have a bluish tint to the light. Then you can do the same at the right and left edge about ½ inch in. Yes you are rough checking the quality of the last chuck grinding and the quality of the bed ways for long travel. Yes poor ways will be most often leave chuck high in the center for a normal wear grinder... a grinder run out of oil can be anything.

The area on the rail and about 4” wide in the center is likely to be the high wear zone and you said the run check showed .0003 so that is a fairly good flat. You can light-look at that place to see what .0003 looks like.

I think you should place grinding work at the near side (away from the rail bump rail) and get some grinding experience. Yes some parallels can shim your work away from the bumb rail.. With tall, wide block-ins to the left of your work.

Also check the slop in the down feed with setting the wheel on a 2" piece of wood and see how much free play.. getting over half turn then start thinking how to replace the nut.

Wet is best so a squirt bottle is first, then a gravity hang bucket, then a tank with a pump.
Yes you don't have any coolant catch method.. bummer, back to the squirt bottle for a time.!
 








 
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