• We want to encourage those of you who ENJOY our site and find it USEFUL to DONATE and UPGRADE your membership from active member to donating or premium membership. If you want to know the differences in membership benefits, please visit THIS PAGE:

    https://www.hobby-machinist.com/premium/

    Donating memberships start at just $10 per year. These memberships are in fact donations that help pay our costs, and keep our site running!
    Thank you for your donation, God Bless You

  • As some of you know, I have wanted to stop managing H-M for some time. It's a tremendous strain on my personal life. I want to set up my own shop. In September, September 15, to be exact, it will be 8 years that Hobby-Machinist has been in existence.

    I have been training VTCNC to run things here. Dabbler is going to learn too. I feel that they are ready to start taking over the operation. I will be here to help in case they need, but I don't think they will. Tony Wells is and will be here also to consult with. I will be doing backups, upgrades, and installing addons. Other than that, I will not be around. I am leaving this place in good operating condition, and financial condition.
    --Nelson
[4]

Surface Grinder Initial Tooling

[3]
[10] Like what you see?
Click here to donate to this forum and upgrade your account!

Dabbler

Administrator Trainee
Staff member
H-M Supporter - Gold Member ($25)
Joined
Oct 11, 2016
Messages
440
Likes
332
#31
On the start up equipment, you have enough to get started and do a lot of different things. You will also need a block to hold the diamond at a 5 degree angle... Contact me if you want me to make a drawing for you. I have an old soft one and am currently making a tool steel, hardened replacement to be my permanent diamond dressing block.

Please don't mill the chuck!!! The alternating layers in the chuck are soft then hard - it takes some special work to do it well, which will probably be unnecessary.

Instead, take most of the bad surface rust off with a 3M pad and varsol or wd 40 or whatever your petroleum lube of choice is. This will tell you about the reall extent of the damage. Remember a hole doesn't hurt you, but a volcano is a disaster. You will be grinding the chuck in anyway, so just clean it up so you can inspect it. If you have more than 90% contact left, then just grind the chuck true and go for it! In subsequent resurfaces, the holes will slowly disappear (!!)

It sounds like your are going great guns!
 
Last edited:

Dabbler

Administrator Trainee
Staff member
H-M Supporter - Gold Member ($25)
Joined
Oct 11, 2016
Messages
440
Likes
332
#32
... duplicate post ...
 

mmcmdl

H-M Supporter - Gold Member
Staff member
H-M Supporter - Gold Member ($25)
Joined
Jan 31, 2016
Messages
563
Likes
441
#33
Grind that mag chuck on the machine other wise you're doubling your work ! I ran grinders of all types for years , cylindrical , surface , blanchards , opticals . Get your self a nice burr buster stone for your mag chuck and a few norbide sticks for dressing radiuss on your wheel . No need to balance your wheels , just let it run to throw any coolant off of it when complete . Norton 32A-46 or 60s are great all around Aluminum Oxide grades . Silican Carbide is a must for grinding carbide . Rule of thumb . The softer your piece is , the courser your wheel choice should be . If you need a diamond and dresser I send one to you just for shipping as I have quite a few !
 

benster

Registered
Registered
Joined
Mar 14, 2016
Messages
47
Likes
9
#34
Thanks for the offers on the diamond dressers! I got one of the basic ones from McMaster, I may take one of ya'll up on your offer if it doesn't work well. I was just going to mount it in a small toolmaking vise with a Vee in the jaws and shim it to a ~5 deg angle for now.
 

benster

Registered
Registered
Joined
Mar 14, 2016
Messages
47
Likes
9
#35
Got the VFD hooked up and configured. Tried to dress it with the McMaster diamond dresser. Not sure if it was meant for actual surface grinders, as it ground the tip off.. I only fed down about .5 tenths at a time, then started getting sparks like metal contact. What kind of dresser should I get and what's a good source?
 

Dabbler

Administrator Trainee
Staff member
H-M Supporter - Gold Member ($25)
Joined
Oct 11, 2016
Messages
440
Likes
332
#36
Hey Benster, I have a fairly cheap 1/4 carat diamond dresser from KBC tools. It works as it should. I also have an old used wore-out 1 carat diamond set in the wrong dressing block, which after some loving care, will still work fine.

I think they sold you a hand dresser. On a hand dresser the diamond is only cold bonded to the stake. What I think happened is that under the pressure of dressing the wheel, it tore the diamond off, and all you had was the stake. It sometimes happens on even the best diamonds, but that's when the diamond is very flat. It should never happen on a brand new stone. A good 1/2 carat diamond should last you for years

- A good 1/2 carat diamond should dress several dozens of wheels dozens of times. Please note that there are natural diamonds (the best, and most expensive) man-made diamonds (cheaper but wears much faster) and CBN crystals sold as diamonds. CBN crystals are only suitable for very soft wheels, I'd guess at C,D,E hardness) and hand dressing of soft (usually white) AO wheels on bench grinders. Hand dressing uses much less pressure on the stone than dressing a surface grinder wheel.
 

Bob Korves

H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
Joined
Jul 2, 2014
Messages
5,254
Likes
5,612
#37
Dabbler gave good information above. Steve Barton, of Solid Rock Machine Shop on YouTube:
https://www.youtube.com/channel/UCKPqKYF73sJbFUSzo5dQxtQ/videos
uses cluster diamonds as well as single point diamonds, and he knows what he is doing. I am also pretty much a newbie at surface grinding, and only have practice with single point diamonds, which work fine and are the traditional choice.
Here is some more information:
http://parasdiamondco.com/Diamond Dressers.html
http://assets.abrasive-tech.com/literature/DiamondDressing.pdf
 

benster

Registered
Registered
Joined
Mar 14, 2016
Messages
47
Likes
9
#38
Those are some pretty good sources, I read through them. I bought a 1/2 carrot single point dresser, holder, and another wheel. Open structure, 7x1, 46H wheel from Travers tool.

What are ya'lls thoughts on grinding a flywheel from my car? It has a groove in it from the previous clutch rivets. Maybe 2 thou deep. In lieu of having it blanchard ground outside, I could set it on a rotary table and feed by cranking the table around. This would at least ensure the flywheel is completely concenctric. It doesn't have to be perfectly flat, just needs to be concentric to the bearing, have a decent finish, and no grooves. I think this would accomplish all of the above.
 

Bob Korves

H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
Joined
Jul 2, 2014
Messages
5,254
Likes
5,612
#39
If the car is just a daily driver, and not your pride and joy forever, I would install a new clutch and ignore the rivet groove. Scratch up the surface diagonally (crosshatch) across the circumferential wear lines with sandpaper, and let the new disc wear in to the existing surface. Been there, done that. It works for a daily driver, not driven hard initially. After it breaks in, it will be as good as it ever was. If it is a hot rod, or your pride and joy, then I would have it professionally ground. I would not do it myself, especially if flywheels for it are rare in the aftermarket.
 

benster

Registered
Registered
Joined
Mar 14, 2016
Messages
47
Likes
9
#40
The car is my daily driver, but its the original flywheel. I replaced it with a lightweight flywheel when I put a new clutch in. I since regret that decision in everyday traffic and will be putting the original back in. I'll heed your advice on getting it professionally ground.

Since the first diamond dresser failed, I shelled out and got a US made 1/2 carat dresser, a holder, and a 46H open structure wheel.

I mounted the wheel, dressed it, then mounted a little 2" toolmakers vise. I started by grinding some prehard 4140 stock I had lying around. After playing around with feeds and depths I "dusted" a couple tenths and took it off to inspect. I put it on the mini granite plate and measured the differential with a 5 tenths indicator. I then verified with a micrometer. End to end (x direction on the grinder) it was 8 tenths off. Crosswise (y direction) it was 5 thou off! I believe this was due to the setup in the toolmakers vise. I had it stacked on two parallels laying down, and I think the piece pulled up when I tightened the vise. It may have also affected the 8 tenths lengthwise. This problem should go away in a mag chuck.

For reference, the piece of stock and mounting on the grinder was 3"X x 1.5"Y x 1"Z.

I'm really tempted to mount the chuck and do a preliminary grind in. The bottom of the chuck does have some rust "volcanoes", and I'm tempted to buff these out with some emory cloth, since even if I do hollow them out, I can mount it flat, grind the top, then flip it back over, grind the bottom completely flat to get good bearing, then flip it and do a final cleanup on the top. Alternatively I can just keep it in place and not flip it over for bearing.
 

Dabbler

Administrator Trainee
Staff member
H-M Supporter - Gold Member ($25)
Joined
Oct 11, 2016
Messages
440
Likes
332
#41
Hello Benster, can you take your 4140 stock and grind it on your mag chuck directly and eliminate a bunch of potential sources of error?

Please be aware that annealed steel is much harder on a surface grinder wheel than hardened stock is. Theory has it that it 'grabs' the grit more often out of the matrix, rather than wearing down the AO particles.

Best of good fortune! :D
 

benster

Registered
Registered
Joined
Mar 14, 2016
Messages
47
Likes
9
#42
I haven't mounted the mag chuck yet due to the corrosion issues. I might give it a shot tomorrow.
 

benster

Registered
Registered
Joined
Mar 14, 2016
Messages
47
Likes
9
#43
Mounted the mag chuck, got it ground in. Took a roughing pass to remove all the corrosion, let the chuck cool, then redressed the wheel. Took another thou off in several passes until the whole thing was getting skimmed. Then, put a piece on it to test grind, only to realize the mag chuck "doesn't work". The on/off lever seems to do nothing, and the magnet is very strong on the right side, and very weak on the left. My current options are to buy a new Shars 8x18 mag chuck, or wait until a used one of decent size pops up on ebay.
 

Dabbler

Administrator Trainee
Staff member
H-M Supporter - Gold Member ($25)
Joined
Oct 11, 2016
Messages
440
Likes
332
#44
One of the youtubers, 'this old tony' I think, rebult his magnetic chuck. It can be done. If you are game, I can look at my viewing history and see if Ii can find it for you.
 

benster

Registered
Registered
Joined
Mar 14, 2016
Messages
47
Likes
9
#45
I tried to disassemble it. Drilled out the plastic that was poured in the bottom fasteners, then was unable to separate the halves. I think they epoxied the top and bottom together. I bought a "new" used magnetic chuck off ebay, a 6" x 18". Should be here next week, but it'll be another week after that before I have time to install it and play around.
 
[6]
[5] [7]
Top