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hitnmiss
12-16-2012, 06:52 PM
Well I waded thru my VFD issues and my old Sanford surface grinder is finally up and working.

I stuck a piece of common cold rolled steel (A36 I'd imagine) and gave a go at grinding my 1st surface.

http://i219.photobucket.com/albums/cc283/hitnmiss_photos/Sanford%20Surface%20Grinder/1B0ACE97-FBA0-4184-ADCA-2CD3C1612BEE-1022-000000F30DD9E84E.jpg


Surface looks pretty wavy to me... Are my bearings shot or is this what you get from A36?

I trued the wheel with a diamond nib before cutting.

Any advice?

lane
12-16-2012, 06:59 PM
Well I waded thru my VFD issues and my old Sanford surface grinder is finally up and working.

I stuck a piece of common cold rolled steel (A36 I'd imagine) and gave a go at grinding my 1st surface.

http://i219.photobucket.com/albums/cc283/hitnmiss_photos/Sanford%20Surface%20Grinder/1B0ACE97-FBA0-4184-ADCA-2CD3C1612BEE-1022-000000F30DD9E84E.jpg


Surface looks pretty wavy to me... Are my bearings shot or is this what you get from A36?

I trued the wheel with a diamond nib before cutting.

Any advice?
May have the wrong wheel . the material does not matter if all is good. You may try a 32A 46 K vbe Norton wheel should work good

atty
12-16-2012, 08:10 PM
That's what my first piece of A36 looked like when I first fired up. A surface grinder is a great machine to make you talk to yourself.....sometimes in unflattering terms.

Like all machines, it takes some futzing around. I tried different traverse speeds, DOC, different wheels, coolant, and they all yielded different results. You have a long way to go yet before you conclude that it's the machine's fault.

Happy Hunting

JoeLee
12-16-2012, 08:26 PM
Did you dress the wheel???? The wavy pattern is an indication of a loaded wheel.

JL................

Grind Hard
12-16-2012, 08:32 PM
Dress the wheel again, you might not have opened the wheel up enough when you dressed it the first time.

I've had brand-new wheels that I've had to dress quite deeply.

oldtiffie
12-16-2012, 08:37 PM
I'd guess that the wheell is only partially dressed - and as JoeLee says - the rest is "blunt" and/or "loaded".

The wheel needs to be a clear white all round - no grey or other stuff - and check while the wheel is stopped.

JoeLee
12-16-2012, 08:38 PM
If all else fails, pull the wheel arbor and indicate the spindle...... see what you have for runout.
Do you feel any vibration in the head when it's running??? noise etc????

JL.................

kz1000
12-16-2012, 08:40 PM
Make sure your arbor or the bushing that go's in the wheel (if any) is not worn. It is possible to have a wheel that is running true , but still out of balance. If its good check your bearings. Also machine must be level and mounted steady on the floor. Surface grinders are finicky about vibration.

JoeLee
12-16-2012, 08:44 PM
Just for the heck of it I would try grinding a hardened piece of steel and see wht you get.
I've found that harder steels tend to have better finishes when ground, I do grind 1018 but don't end up with that bad of a pattern.
I use a 60 grit ruby wheel,it seems like you can go for ever with out dressing it and it generates much less heat.

JL......................

oldtiffie
12-16-2012, 09:10 PM
If the wheel is mounted on a balancing hub the wheel needs to be balanced by using the balancing hub adjusting weights.

http://i200.photobucket.com/albums/aa294/oldtiffie/Precision_grinding/Wheelbalance8.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Grinding_Wheels/Wheel_balance1.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Grinding_Wheels/Wheel_balance2.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Grinding_Wheels/Wheel_balance3.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Grinding_Wheels/Wheel_balance4.jpg

If the wheel is on a balanced hub and the hub cannot be removed, set the balancing weights to "neutral" ie equi-spaaced.

Mcgyver
12-16-2012, 09:18 PM
There are so many things that can cause that. First try the basics; dress the wheel and don't turn it off. try only advance the Z axis 1/8" per pass - grinding should overlap and a small overlap (width of cut) will reduce the bouncing. rig it for flood coolant. A wheel that works well on hardened won't do so well on soft, a try a slightly harder wheel. Ideally its 3 phase using the original balanced motor. Trying some of that will likely improve things but getting the perfect grind on a light duty machine can take a bit but its doable.

oldtiffie
12-16-2012, 09:28 PM
Frankly, if the OP's surface was good enough for the job required its good enough.

I use the coarsest wheel I can for the job.

Some people are more concerned about "looks" than than a surface finish which is adequate for the job - ie the "Surface finish" as a mirror finish is not always required but a lesser surface finish may well be adequate.

Read up on "surface finish".

http://www.google.com.au/search?q=surface+finish&hl=en&tbo=u&rlz=1R2IRFC_enAU360&tbm=isch&source=univ&sa=X&ei=hILOUL2cO-j0mAWqwYHoCQ&sqi=2&ved=0CEwQsAQ&biw=1920&bih=846

http://en.wikipedia.org/wiki/Surface_finish

http://www.google.com.au/#hl=en&sugexp=les%3B&gs_nf=3&gs_rn=1&gs_ri=hp&cp=10&gs_id=12&xhr=t&q=surface+finish&pf=p&tbo=d&output=search&sclient=psy-ab&oq=surface+fi&gs_l=&pbx=1&rlz=1R2IRFC_enAU360&fp=1&bpcl=39967673&biw=1920&bih=846&bav=on.2,or.r_gc.r_pw.r_qf.&cad=b

Mcgyver
12-16-2012, 10:38 PM
Some people are more concerned about "looks" than than a surface finish which is adequate for the job - ie the "Surface finish" as a mirror finish is not always required but a lesser surface finish may well be adequate.



What are you on about now? The thread is about the OP asking about a finish he's not happy with; why and what to do about it.

tdmidget
12-16-2012, 11:44 PM
The OP has not given enough info, there is no such thing as cold rolled A36 steel. There is no such thing as a "ruby" wheel, only "ruby" colored wheels. What is the work piece? What is the wheel? What is the depth of cut? What is the feed? What is the SFM?
Most who have answered have shown that that they know nothing about the subject. Without the information that you left out no one can help you.

JoeLee
12-17-2012, 12:06 AM
The OP has not given enough info, there is no such thing as cold rolled A36 steel. Thetre is no such thing as a "ruby" wheel, only "ruby" colored wheels. What is the work piece? What is the wheel? What is the depth of cut? What is the feed? What is the SFM?
Most who have answered have shown that that they know nothing about the subject. Without the information that you left out no one can help you.I do admit the OP is lacking info but is asking for advise. The pattern on his test piece doesn't look to be from improper DOC or feed rates, if it were there would be some discoloration from heat.
I'm not sure if the ruby wheel is actually ruby crystals or dust but it's the best wheel I've ever used and the only one that I've had on my grinder in over two years. You would be amazed at how much grinding you can do before having to redress.
http://www.huronindustrial.com/mm5/merchant.mvc?Screen=PROD&Store_Code=his&Product_Code=1-705-005&Category_Code=7

JL.....................

oldtiffie
12-17-2012, 12:14 AM
I'd suggest that the OP have a look at the makers name on the wheel. If it is a "Norton" and not in excess of 7" diameter it will be well-enough balanced from right out of the box to its minimal useful diameter. If its another (cheaper) brand I'd suggest getting rid of it (ie breaking up).

The dresser diamond should be positioned 5/8">3/4" LEFT of the centre of the wheel spindle IF the wheel is rotating clock-wise (viewed from the front of the wheel).

tdmidget
12-17-2012, 02:05 AM
[QUOTE=JoeLee;816439]I do admit the OP is lacking info but is asking for advise. The pattern on his test piece doesn't look to be from improper DOC or feed rates, if it were there would be some discoloration from heat.
I'm not sure if the ruby wheel is actually ruby crystals or dust but it's the best wheel I've ever used and the only one that I've had on my grinder in over two years. You would be amazed at how much grinding you can do before having to redress.
http://www.huronindustrial.com/mm5/merchant.mvc?Screen=PROD&Store_Code=his&Product_Code=1-705-005&Category_Code=7

Yeah I'm sure that Huron industrial is crushing rubies to make $16.00 grinding wheels. Or not. LOOK at the code on the blotter. If the letter before the grit size is "A" then it is aluminum oxide, which is snow white in the pure form. If it is pink then a dye has been added to make rubes tHink it is something special, like ground up rubies. Get real. Learn the wheel codes. If you have been using the same "ruby" wheel for 2 years then your experience is negligible. And why is it only available as J and K hardness? Not much of a supplier with that wide spread of merchandise. 123

oldtiffie
12-17-2012, 03:24 AM
Here is the OP:


Well I waded thru my VFD issues and my old Sanford surface grinder is finally up and working.

I stuck a piece of common cold rolled steel (A36 I'd imagine) and gave a go at grinding my 1st surface.

http://i219.photobucket.com/albums/cc283/hitnmiss_photos/Sanford%20Surface%20Grinder/1B0ACE97-FBA0-4184-ADCA-2CD3C1612BEE-1022-000000F30DD9E84E.jpg

Here is my post that you are concerned about:

[QUOTE]Originally Posted by oldtiffie

Some people are more concerned about "looks" than than a surface finish which is adequate for the job - ie the "Surface finish" as a mirror finish is not always required but a lesser surface finish may well be adequate.


What are you on about now? The thread is about the OP asking about a finish he's not happy with; why and what to do about it.

It may well be that if the OP only requires a finish as per his post then his needs are satisfied. But he didn't actaully say that. People here could only work on the inforamation provided by the OP.

Its knowing what kind/level or surface finish that he needs as opposed to what he wants that is the real question that may be implied if not implicit in his OP.

I've more than adequately covered how to improve it - as have others - so that ground has been covered.

It is now up to the OP to systematically and logically work his way through the remedies/options/methods suggested by others as well as me.

I'd be looking at the spindle as a last resort - but putting a glass of water on the grinding head - with and without the wheel mounted - might narrow the problem down to the wheel and spindle - the "wavelet" frequency and amplitude will give a good indictation. "No waves" is pretty well impractical.

Black Forest
12-17-2012, 03:51 AM
The OP has not given enough info, there is no such thing as cold rolled A36 steel. There is no such thing as a "ruby" wheel, only "ruby" colored wheels. What is the work piece? What is the wheel? What is the depth of cut? What is the feed? What is the SFM?
Most who have answered have shown that that they know nothing about the subject. Without the information that you left out no one can help you.

You forgot to include the word worthless in your response. Are you related to JTeirs?

.RC.
12-17-2012, 04:04 AM
Well I waded thru my VFD issues and my old Sanford surface grinder is finally up and working.

I stuck a piece of common cold rolled steel (A36 I'd imagine) and gave a go at grinding my 1st surface.




Surface looks pretty wavy to me... Are my bearings shot or is this what you get from A36?

I trued the wheel with a diamond nib before cutting.

Any advice?

Hard to say... Myself only owning a surface grinder since the start of the year I have found there are a huge number of variables at play to get a good surface finish...

Wheel type, how you dress, wheel speed, work speed, the variables seem to be endless, I even think the phase of the moon has some bearing on getting a good surface finish...

I think coolant is important, but others probably think less so...

polepenhollow
12-17-2012, 09:10 AM
I have an older Sanford also and have had to go through a process of elimination to get a better surface finish.
One of the benefits you have is a 3 PH Motor, mine is single phase. 3 PH gives a better finish. A Single Phase motor gives a power pulse input to the spindle.
Here are some of the things done to improve the surface finish when grinding.
First of all, dress the wheel well, both the face and vertical surfaces. Use a single point diamond, I had to buy new Sopko wheel hubs for mine, it came with none.
1) Changed a solid mount motor to a resilient mount motor.
2) 32A46H8 wheel for general flat and side grinding. .0005 or .001 down feed, 1/2 or
handle rotation for crossfeed. For finish, make free pass. This is using a 1/2" wheel.
3) 60 grit for a more of a finished side grind. 60, 80 and 100 J, K and L wheels for sharp
corners. Dress face and sides w/ diamond, and then clear sides to a single grain sharp
edge using a Carborundum stone.
4) Replaced spindle bearings.
5) Make sure gibs on the vertical ways are properly adjusted
6) Resurfaced both spindle and motor pulleys on the belt surfaces.
7) Replaced the V belt with a new one. I intentionally used a nylon reinforced belt rather
than a steel reinforced V . I felt the nylon would give a smoother and less rigid input
to the drive.
8) The grinder has a double shafted motor; I made a flywheel 6" dia by 1" for the other
side of the motor.
9) Bolted plates of steel, about 3" x 12" sq total to the motor mount to cancel vibration.
10) Put a few brake drums and rotors in the bottom of cabinet to give it mass and cancel
vibration.
11) Put the machine feet on resilient pads, or if not, on pieces of heavy corrugated
cardboard. Carpet square samples from the Home Builders Store may work?
12) Replace drive gear and gear rack on table. These parts are available from gear
supply houses. They must be machined to fit the Sanfords parameters. This has not
been done yet. This is the next step, Right now the finish is acceptable. When I have
to go more for finish appearance of work this step will be done.

hitnmiss
12-17-2012, 10:02 AM
Thanks for all the advice gents. When I said newbie, I meant it.

polepen, that's quite a list! I don't know if I'll get to all that... To be honest, I don't really know what I'm going to do with this surface grinder. If I need to get serious I'll march down your list for sure.

After reading, I think a big problem is I probably didn't dress the wheel enough. I just got it true and called it good, I think dressing a little deeper would give better results. I do feel an imbalance when the machine is running, not severe but it's there. I suspect the belt has taken a set and needs replaced.

When I shut the machine off, it doesn't coast all that long, maybe 3 seconds. I expected more. Not the VFD cause I timed it shutting off on the rotary too. It turns free enough though.