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How much grinder do I need?

Joined
Apr 14, 2018
Location
Airstrip One, Oceania
What about a small Blanchard grinder? Your budget is more than enough.

Agree with you that Blanchards are cool but when I was looking for one, the prices .. cheap ones were thoroughly trashed and good ones were not so cheap.

Also, for general work, a normal surface grinder is more versatile.

My No.11 would grind those parts perfect all day everyday. If you’ve never used one before, you’d be shocked at how fast material can be removed and the grind quality.

You could quote the job, it might be a marriage made in Practical Machinist :)
 

Houndogforever

Hot Rolled
Joined
Oct 20, 2015
Location
Boring
The purpose of the surface grinding is that seals against a surface on the machine and paste is squirted thru the slot and thru some .031 diameter holes.
Is a blanchard grind as smooth as surface grinding? Or does it have a coarser surface which may leak?
 

Houndogforever

Hot Rolled
Joined
Oct 20, 2015
Location
Boring
This might be just a tad small, but it seems to fit my requirements.
What are your opinions of this machine for this job?

Chevalier FSG-2A618 High Precision Surface Grinder​

 

eKretz

Diamond; Mod Squad
Joined
Mar 27, 2005
Location
Northwest Indiana, USA
Blanchard machine should be good enough surface finish with the right grit, but I'm with EG. A conventional surface grinder is way more versatile. Blanchards are good for flat surfacing only. A regular surface grinder is like a swiss army knife of grinding. That last machine looks like it could fit the bill; but as already stressed by myself and Stephen: condition, condition, condition.
 

michiganbuck

Diamond
Joined
Jun 28, 2012
Location
Mt Clemens, Michigan 48035
Our guys at Cutmore would fill a Blanchard chuck with parts like that with the parts set on wires.. but that takes more Blanchard skills than I have.
I have run a 36" long row of similar parts as the Ops set on wires on a surface grinder with down grinding. Dressing the wheel to angle is much easier than on wires.

Stephen , I know that dealers work.. that Do All would be near mint​

 

Garwood

Diamond
Joined
Oct 10, 2009
Location
Oregon
What kind of machines do you have? Have you tried hard milling them?

I might be interested in grinding these if you don't buy a grinder. I need to set up my surface grinder to do a similar job on a recurring basis.

My shop is a ways from Boring though. I'm out in Mcminnville, but I have friends in Clackamas that I visit regularly.
 
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Houndogforever

Hot Rolled
Joined
Oct 20, 2015
Location
Boring
Well I just received an email from the guy and somebody stopped by today and bought it.

Well garwood, maybe you should contact me about these. I don't need any done now and still in the market.
I wonder what that doall would cost to ship cross country?
 

eKretz

Diamond; Mod Squad
Joined
Mar 27, 2005
Location
Northwest Indiana, USA
What kind of machines do you have? Have you tried hard milling them?

I might be interested in grinding these if you don't buy a grinder. I need to set up my surface grinder to do a similar job on a recurring basis.

My shop is a ways from Boring though. I'm out in Mcminnville, but I have friends in Clackamas that I visit regularly.

You should. If I wasn't more than half way across the country I would've...
 

michiganbuck

Diamond
Joined
Jun 28, 2012
Location
Mt Clemens, Michigan 48035
Keep in mind the Do All is a 618 and you are thinking about a larger machine.,
The Do All is a manual machine with down, cross and long travel auto feeds. On a machine like that I very often run a one-up or few-up just cranking the hand wheels.
Having a DRO for down and cross can be handy. Having a programable down and cross can be handy. Good to check the variance produce with the fixture part to part , and one load to the next along with how much time is used for measuring.
With a set diamond height it should be possible to eliminate almost all measuring and grind directly to +- .0005.
Down grinding with using your fixture may be very good.. You down grind to +.001 (or what)skim dress and finish the .001 (or what).
Still and always, the chuck and back rail are the most precise work holding methods/locators, and often the fastest set-up.
 
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michiganbuck

Diamond
Joined
Jun 28, 2012
Location
Mt Clemens, Michigan 48035
One often made mistake is not changing wheels. Often parts are ground with a much higher quality surface finish the the spec and so, much time is wasted.
A 54 gt is heading toward fine finish. 46 a very good finish and fair production speed courser than 46 and often a job can de ground faster than milled.
Down grinding is often served best with 46gt and courser wheel.
 
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michiganbuck

Diamond
Joined
Jun 28, 2012
Location
Mt Clemens, Michigan 48035
You can keep your eye open on eBay but they don't come up often, a 46 more open wheel is the the next best thing, you can call Radiac to get good information and order a wheel.
Wheels are often made for longer wheel life and are not always the best wheels for one and few ups, 0r for odd needs-up
 
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AD Design

Stainless
Joined
Jun 27, 2012
Location
Tennessee USA
Is there a reason why you don't just mag hold them on the chuck?
Are you grinding 2 sides or 6 sides?
-If this has been mentioned already then just ignore my comments. The OP stated that the work pieces needing to be ground are hardened D-2. As has been mentioned, hardened D-2 is usually a less-than-pleasant material to be ground but it's also a restless material on a mag-chuck. It may appear to hold, even resist a light push with fingers, but it should really not be trusted to hold well on a mag-chuck. For those of us that are/have been die makers there's often a regular diet of hardened D-2 being fed to the surface grinder. A good size hunk of D-2 with a proportionate surface to go flat down on the chuck will seem like it's a go. Part way into the grind that hunk will be wanting to leave the chuck like a faithless lover. It may start twitching in slight movements (Sharpie helps determine this) or it may just decide to launch out of the grinding area (Houston we have lift off...), prompting many complimentary remarks from the other toolmakers. It may be possible to line up a batch on the chuck if there's a squeeze from either end via a fixture but I still wouldn't trust hardened D-2 in the SG unless it was held in a grinding vise, clamped to an angle plate, or held in a bedded fixture like the OP had. You may even get away with one or two pieces that only require .001 dust off but when .005-.010 and the ensuing heat are combined it's a roll of the dice with bad odds. YMMV but I don't think so.
 
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eKretz

Diamond; Mod Squad
Joined
Mar 27, 2005
Location
Northwest Indiana, USA
-If this has been mentioned already then just ignore my comments. The OP stated that the work pieces needing to be ground are hardened D-2. As has been mentioned, hardened D-2 is usually a less-than-pleasant material to be ground but it's also a restless material on a mag-chuck. It may appear to hold, even resist a light push with fingers, but it should really not be trusted to hold well on a mag-chuck. For those of us that are/have been die makers there's often a regular diet of hardened D-2 going into the surface grinder. A good size hunk of D-2 with a proportionate surface to go flat down on the chuck will seem like it's a go. Part way into the grind that hunk will be wanting to leave the chuck like a faithless lover. It may start twitching in slight movements (Sharpie helps determine this) or it may just decide to launch out of the grinding area (Houston we have lift off...), prompting many complimentary remarks from the other toolmakers. It may be possible to line up a batch on the chuck if there's a squeeze from either end via a fixture but I wouldn't trust hardened D-2 in the SG unless it was held in a grinding vise, clamped to an angle plate, or held in a bedded fixture like the OP had. You may even get away with one or two pieces that only require .001 dust off but when .005-.010 and the ensuing heat are combined it's a roll of the dice with bad odds. YMMV but I don't think so.

I have had it move, but never shot any out. At least, not since my apprentice days... I would be comfortable doing a line of these on a sine chuck, so long as they were well blocked in with blocks just below the height of the parts. I think that goes without saying for the more experienced guys though: grinding a tapered part on a sine chuck could be an absolute catastrophic disaster if the part slipped and caused a heavier cut due to the part climbing up the angled chuck. Probably be kissing the wheel goodbye along with needing a new pair of underoos.
 

implmex

Titanium
Joined
Jun 23, 2002
Location
Vancouver BC Canada
Hi Houndogforever:
I'm a big fan of modifying magnetic parallels for this kind of work.
If the surfaces need to be non parallel, you can just put that shape into the parallel as many times as you can get parts into the length of the parallel and line up as many parallels along the mag chuck as you have length for.
Yeah, you have to buy and mod the parallels, but you only need to do it once.
One of the big advantages of doing it this way is that you can do a conventional dress and a conventional grind with the corner of the wheel as if you were grinding plates.
If you have an overhead dresser you can dress the wheel easily and for D-2 I've always really liked that capability.

Mag parallels are pretty cheap, and you can cover the whole mag chuck with them if you want to.
Put a rail or pair of stop pins at the head end of each block so the wheel can't push it off the proper location and you're good to go.

Moving on to the grinder.
I used to have 10 x 20 Kent.
Now I have a 6 x 18 Jones and Shipman.
In my opinion neither is hunky enough to really do production grinding on D-2 blocks, even though both grinders will do just fine for limited runs.
You need something with more balls...5 ponies or more on the spindle and a 12" wheel if production surface grinding of D-2 is your goal.
I've had decent success with the blue seeded gel wheels from Norton.
I buy 46J wheels.

I do as Stephen Thomas recommends; try to take almost all of your grinding allowance in one deep cut but with a very small crossfeed so the corner of the wheel doesn't wear into a wide contact band but remains confined to the corner of the wheel.
It will eventually wear all the way across the wheel face but never into that wide band that is the kiss of death for grinding D-2.
This is how we used to dress chipped punch dies...if we ground them conventionally, we'd never get there.
We'd be fighting burns and suck marks and huge wheel pressures with flung parts forever.
This strategy allowed us to take 30-40 thou in one pass and just set up the grinder and let her go while we went off and did something else.
Our crossfeed was typically between 0.0005" and 0.001" so it still took a long time but nobody cared.

So yeah, a nice stout hydraulic grinder, a set of modified mag blocks, a coarse seeded gel wheel, lots of coolant and a deep DOC with small WOC and you should be good to make bazillions of these efficiently and painlessly.

Doing them on a Blanchard as hobbyshop prefers is another good way but you need access to the Blanchard and I doubt there's all that many around that are small enough to want to have in a reasonably sized shop.

Cheers

Marcus
www.implant-mechanix.com
www.vancouverwireedm.com
 

michiganbuck

Diamond
Joined
Jun 28, 2012
Location
Mt Clemens, Michigan 48035
The deep drop (10-40 thow about) and fine incremental small cross feed with each long travel was the way I was taught to grind, with cross amounts as much as .002 - .020 or so. the same as Marcus and Stephen suggests. The wheel lead edge and the bottom toward the front wear.. and the following stays at height to be the finisher portion of the wheel, so a very good way to grind.
The cross step over method of 1/4 or so of the wheel never seemed good except maybe for a .001/.002 drop.
Now with much stock .020 to .200+ or so I put on a course wheel 46 open or courser and down grind to + .006 or .010, let the part cool and with a dress take the rest with an incremental cross grind.
Down grinding is to drop .001 or .010 with each long travel with the full wheel, parts have to be well blocked with sufficient horsepower., and stocky enough parts that they will not warp.. and the wheel has to be tight enough that it will not turn on the mount.

I think mag parallels and specials with an angle are great. A/One trick is that you have a block-in in the go direction that touches the part high up close to the wheel, normally you can grind blue blazes with a high-up block-in.

One trick with a tall part is to block it high in the go direction, and then feed on the grind-side only, then pass back on the climb-side with no stock-taking.
One such part in trade school was a pendulum, 5" in diameter and about 20 " long. with the point end down on the chuck and the upside about 3"dia with a screw in part that they wanted flush and dead square. nobody, not even the send-out shop wanted the job. it would still be a tough/be careful job for me today.
 
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