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View Full Version : Surface grinder finally works!



Doc Nickel
11-07-2009, 04:17 PM
It still needs a proper power supply, but I have parts for an RPC on the way. That'll also get me coolant and the vacuum, but for the moment, it's working with the VFD I robbed back off my Logan lathe.

As a first test piece, I hit this- it's one of the stock jaws off my Kurt-clone import mill vise. It's dished a bit, and too hard to cut. I've long since replaced them with mild steel soft jaws, but it makes a great practice piece.

http://www.docsmachine.com/machineshop/1stgrind01.jpg

The hand feed can get a bit tedious, but it's not bad.

http://www.docsmachine.com/machineshop/1stgrind02.jpg

The piece was just a tad taco-shaped, and you can see the fine grooves from the original machining process- which I suspect it was made on a shaper. The lines are too uniform for a belt or stone grinder.

http://www.docsmachine.com/machineshop/1stgrind04.jpg

The camera makes it look rougher than it is, but the surface is very smooth indeed. It'll actually "wring" to my surface plate.

http://www.docsmachine.com/machineshop/1stgrind07.jpg

There's a very, very faint "cogging" texture to it, but that goes almost entirely away if I do a light finish pass. I've also removed and remounted the wheel, so the original balance- if it'd been balanced, it came out of a high school shop- was lost. (Yes, I dressed it.)

That came out so well I've already ground an old garage-sale sine bar that had some tarnish, a shopmade V-block I got with some other junk last year, and a couple of small bits of junk just 'cause I could.

Now it's time to start stocking up on more wheels, hubs, a balancer, magnetic parallels, more dressers...

Doc.

Walter
11-07-2009, 05:53 PM
Doc,

Congo rats!

It's hard for me to imagine life without a surface grinder. Glad you got a nice little machine.

motorcyclemac
11-07-2009, 06:01 PM
Doc..

I am green with envy. I HAVE to get a surface grinder next. I have everything else..BUT that. Must....have...one....NOW.

I used to have access to one in the shop I worked in last. I miss having that ability. There are times that you just can't do without one.

Cheers
Mac.

Doc Nickel
11-07-2009, 06:23 PM
Sine bar, before:

http://www.docsmachine.com/machineshop/1stgrind09.jpg

And after (technically just the other side.)

http://www.docsmachine.com/machineshop/1stgrind10.jpg

And the mag-chuck itself:

http://www.docsmachine.com/machineshop/1stgrind12.jpg

That was only about an 0.0007" cut. After I've had a chance to get everything settled in, I'll give it a full-contact pass.

But it's not too bad for only about $600 so far. The RPC parts were another $250, and I've already picked up a few more wheels and hubs which are on their way. The RPC, however, is also saving me the cost of buying VFDs for the Wellsaw and the pedestal grinder, which would have run me another $450 or so including shipping. So I'm happy with how it's coming out.

Besides, I already did a $120 customer job on it. :D

Now I'm plinking away at "rebuilding" one of the little 4" mill vises I just got. The quality is atrocious- even for Chinese- but I think it'll work. The grinder is squaring things up nicely.

Doc.

Walter
11-07-2009, 06:23 PM
It's funny how one never really thinks much about a SG untill they have one at their disposal. Then you miss the hell outta them if you don't have one at hand. I just recently did a job on one that I could imagine doing manually on a mill, but hate the thought of. I could see it being done on a CNC mill, but even that would be a pain in the arse, But the SG made it trivial.

a good compound mag sine and a spindex will get you far :)

motorcyclemac
11-07-2009, 06:29 PM
a good compound mag sine and a spindex will get you far :)


You are right about that. I also used to use a 5C collet holder base. It worked well for dressing the end of endmills. Saved a ton of time and cost so I didn't have to send mill cutters out for sharpening.

Cheers
Mac.

wierdscience
11-07-2009, 06:33 PM
Good job Doc,I bet you'll like it even more once the coolant is up.

Did the wheel dresser work okay?

Doc Nickel
11-07-2009, 06:49 PM
If you mean the onboard dresser, it's missing pieces and jammed somehow. I haven't fixed it yet.

By luck I already had a diamond mounted in a small block of steel- someone's homebrew/shop-made dresser. I got it with the same batch of miscellaneous pieces as the sine bar.

That dresser works great, though while the diamond still has some life left, it's a bit rounded and dull. I can definitely tell the difference in surface finish between a used and newly-dressed wheel.

And yes, I can't wait for the coolant- actually, the vacuum is probably more important. :D I suspect I'll use the vac a lot more often than the coolant, simply due to the mess. The grinder's out in the main shop away from the machine tools, next to the welders and whatnot, so the extra grit isn't too much of a problem.

And yeah, I've got yet another machine I need to tool up. :D

I have a set of magnetic parallels and some V-blocks on the way, I ordered two more hubs and I've already made a spanner wrench. When the hubs get here I'll make a puller and a balancing arbor, then I'll have to make a balancing stand...

I have a spindex for the mill, I may get another cheap one to keep with the grinder. Maybe another set of 5C blocks, some of the quick-and-dirty endmill sharpening fixtures, an adjustable-height dresser...

It never ends.

Doc.

easymike29
11-07-2009, 06:51 PM
.....The hand feed can get a bit tedious, but it's not bad.
Doc.

If the hand feed seems tedious I suspect that you are using small increments on the cross feed. Instead of that keep the cross feed moving all the while you are cranking the table. Use about 1/3 to 1/2 of the wheel width on each pass. When your wheel has cleared the edge of the workpiece about the same amount reverse the cross feed and go back the other way. Don't allow the wheel to completely clear either edge before reversing. Keep up this process, down feeding when appropriate until the part is almost to size. When near net size redress the wheel and take your final sizing and spark out passes. Practice, practice, practice.

Gene

smalltime
11-07-2009, 07:02 PM
That was only about an 0.0007" cut. After I've had a chance to get everything settled in, I'll give it a full-contact pass.



Doc.

A couple things I always try to do:
#1 Always grind the chuck while it's ON. Trust me it makes a difference.
#2 Be shure any and all lube systems are working and have had time to "soak" the ways. This can be a deal breaker if you are anal about flatness.

This does look like a fine machine though. Congrats:D

psomero
11-07-2009, 07:34 PM
it's always good to see old tools brought back to life.

my friend's shop recently picked up a bridgeport surface grinder for $600 from the shop across the parking lot from the building they recently relocated to.


it "didn't work" but they managed to have it run just fine after wheeling it into their space and hooking it up. to really sweeten the deal, the original owners said they'd give them the $600 back if they weren't completely satisfied...




i need to keep my eyes peeled for such a good deal. i've wanted a surface grinder for a long time, but don't really have the space for one, although i would jump on one if the opportunity ever arose...

Mcgyver
11-07-2009, 07:50 PM
There's a very, very faint "cogging" texture to it, but that goes almost entirely away if I do a light finish pass. .

hey Doc, congrats! chasing away that last bit of ripple is almost impossible, at least with the size of machines we end up with. Mine is almost perfect, but a very critical eye in the right light can spot the every so slight ripples. add coolant, balance motor, get the three phase balancing just right, balance and dress the wheel, all steps to minimize it


a good compound mag sine .......will get you far

I picked one up recently but expect it will see very limited use in model making/tool making....I can see if you're going die work where lots is done on angles, but am curious what are doing on the mag sine that gets you so far?

Walter
11-07-2009, 08:47 PM
a good compound mag sine .......will get you far
I picked one up recently but expect it will see very limited use in model making/tool making....I can see if you're going die work where lots is done on angles, but am curious what are doing on the mag sine that gets you so far?
I do tool and die work for a living. While it isn't something one "needs" it's damn nice to have the option. Maybe I should have phrased my comment a bit differently. What I was implying is that it's one of those tools "I" would rather not do without. I learned to work with little in the way of accessories and appreciate having them greatly. Same with the spindex, vise, squaring block, etc. :)

Mcgyver
11-07-2009, 10:40 PM
I do tool and die work for a living. While it isn't something one "needs" it's damn nice to have the option. Maybe I should have phrased my comment a bit differently. What I was implying is that it's one of those tools "I" would rather not do without. I learned to work with little in the way of accessories and appreciate having them greatly. Same with the spindex, vise, squaring block, etc. :)

hey Walter I wasn't challenging the statement, I legitimately am curious what you're grinding with with it....I do lots tool making and model engineering and the need for precision grinding of angles is rare, at least with what i've encountered. Precision grinding vise, angle plates, tool makers cubes, v blocks (all precision ground or scraped) get used lots but where does the angle stuff come into play? maybe in die work its more of an issue? I've got one that rarely sees service so maybe i'm missing a bunch of uses for it..... share the wealth :)

Doc Nickel
11-07-2009, 11:08 PM
#1 Always grind the chuck while it's ON. Trust me it makes a difference.

-Way ahead of ya. :D


#2 Be shure any and all lube systems are working and have had time to "soak" the ways.

-The ball ways are greased, but not pressurized. I'm just supposed to squish a few pumps in there every now and again. The saddle ways are hit with a spring-loaded one-shot oiler. Yank the handle and it pumps out a measured quantity at it's own rate.

But so far I'm not yet grinding to tolerance or to dimension. It's just for fun or for looks at the moment while I get used to the machine. I've ground the parts for my little 4" vise already, but none of it was to any particular size, just shave it down 'til the old machine marks are gone, etc.

After I've done a little more playing, I'll start shooting for specific sizes, checking for parallelism and squareness, and so forth.

Doc.

Mcruff
11-07-2009, 11:09 PM
As far as a diamond dresser, a fabbed one mounted on the chuck will almost always give a better finish than the overhead dressers.
To keep the diamond sharp and make it last, drill and mount the diamond at a 30* angle in the block, after abouta month rotate the diamond in the holder about 15-25* and this will keep it sharp for years an years. I have been usin gthe same diamong in my basic dresser for more than 20 years.
A few other things to do for your dresser. Make it out of tool steel and harden it, that way the grit will not damage it or it wil not dent if accidently dropped. Make sure you grind all sides square so you can dress the side of the wheel with it also if need be.

When dressing the chuck, turn the magnet on and use oil to help lube and cool the chuck.

Walter
11-08-2009, 01:45 AM
hey Walter I wasn't challenging the statement, I legitimately am curious what you're grinding with with it....I do lots tool making and model engineering and the need for precision grinding of angles is rare, at least with what i've encountered. Precision grinding vise, angle plates, tool makers cubes, v blocks (all precision ground or scraped) get used lots but where does the angle stuff come into play? maybe in die work its more of an issue? I've got one that rarely sees service so maybe i'm missing a bunch of uses for it..... share the wealth :)

Mcgyver :)

No worries, it wasn't taken as a challenge but it did make me think of other words. Anyways, myself and the other gent that run the tool room are called on to make everything from blanking, stamping and marking dies, to repair and replacement parts for machinery that seems to date back as far as maybe the 30's - 40's. We also spend much time reverse engineering dies and knives, some of which were made back around 1910 or so. In addition to that stuff, we end up designing and building new process machinery as well.

Our one and only surface grinder has an abomination of a sine plate on it that's maybe 8x18? (sorry, never measured it) and a mag that's 6x12 mounted on it. A very effective setup for sharpening dies as they get mostly simple angles. But it's a giant pain in the arse otherwise. It's not, due to it's design, able to get much better than maybe 5 and that's it. Again, fine for setting shear on a punch but that's about it. It's huge, heavy an not worth the effort to remove even once a month.

Last week I had to make what we call a swedge, it's simply a form made from D2 that we use to press an impression into a forming block with. The forming blocks are for bolsters and caps on our knives. Some very simple, some reasonably complex. A very crude process really, but a fast easy way to make solid caps and bolsters with what we have for equipment. Anyways, this was a remake of an old style swedge that will be getting engraved before being used to create a forming block. This thing was rectangular with a 1.5" radius on the face and top, as well as a 1 taper along the face. And also a 5 taper on both sides from bottom to top. Obviously the sides were easy, then it's time to wing it a bit.

http://img248.imageshack.us/img248/3613/swedge.th.jpg (http://img248.imageshack.us/i/swedge.jpg/)

http://img689.imageshack.us/img689/8151/swedger.th.jpg (http://img689.imageshack.us/i/swedger.jpg/)


I turned a chunk of 1018 for the proper radius, and then turned down a shank to fit a 1" 5C in the spindex. Set the swedge on the face of the 1018, set it off an angle plate square to the back and properly centered. Grind the radius on the top of the swedge and then pull it apart and reset the swedge so that I can do the face. So the radius is easy, but that tapers a pain with the current setup. What I was left doing was faking it and approximating the taper using shims under the front of the spindex that happened to be, due to size constraints, hanging 1/2 way off the front edge of the mag...

Compound angles, not too often, but a compound mag would have made life a lot easier that day, and on many others. I guess it's really a situational thing... really don't need a compound mag sine, but I'm all for working smarter, not harder.