Running belts on a surface grinder.

Fellhoelter

Fellhoelter

Well-Known Member
I really used my converted surface grinder today.
I had played around with it a bit a couple of weeks ago, grinding a blade, but I got down to business tonight.

I have a 90 duro wheel, which seems plenty hard, and was able to take .010" off at a whack in annealed CPM154.
I've seen people say they get ten at a time with a belt, but never believed them.
Not for a second did I believe it.

I have hundreds, perhaps thousands of hours standing in front of a surface grinder as a toolmaker and thought "no way"
Switching to a belt was a hard thing for me to do, because as a machinist, it's just wrong.
Wrong I tell you.

But, here I am now, with a belt, taking off .010" in 1 pass, with almost zero heat build up !!
No heat !

I took 6 folder blades down .026" in 20 minutes, ending with an A45 gator belt.
that's a lot of metal, in not a lot of time.

I'm impressed, I can't wait to master this new system.

Never once did I feel in peril of throwing parts of the chuck.
There was no heat.
Parts are flat and parallel within 2 tenths.
These were things that concerned me...

.010" with a 60 grit belt @ 90 degrees to the cutting edge
flip, do the same on the other side.
Bam, .020" off in 7 or 8 minutes.
Lay parts so grind is now parallel to cutting edge, and take .002" off with an A45 Gator, then .001"
Flip, and do it again.
Done.

I still have .008 to go after heat treat, we'll see how it does on hardened stock.

All in all, unbelievable.

Edit : Adding a link to pictures.

Built a quick page on my site with some pics.

Picture here is a link to that page.
 
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:biggrin::biggrin:
Welcome to "the dark side"!

I had to smile when you said:
Switching to a belt was a hard thing for me to do, because as a machinist, it's just wrong.
Wrong I tell you.
Click to expand...

I've heard that from a lot of folks.....but sometimes we have to "unlearn" something before we can learn something new.

When your doing your post heat treat surface grinding, just keep the down pressure light...the more down pressure you apply, the more likely things will convex on you. This will of course heat up a bit more when hardened, but it's never been like it was when I used stones on the machine.
I've also discovered that some of the structured abrasives, particularly the "gator" belts are sometime not the best choice for the surface grinder....in some cases the grit will "hollow"out and create a small ridge in the workpiece....but if your cautious and aware you can catch it before it goes too far.

Glad to hear the that belt conversion is working for you! I suspect that like most of us who have done it, now you'll never want to use stones on the machine again.
 
It'll be some days before I get to the post heat treat grinding, but I don't expect to have a problem.

Finish passes will be nice and light, I am grinding with a rubber wheel !

Good to know on keeping an eye out on the Gators, I only used it because I had it, and I figured I could dress it real nice.

I bought half a dozen a couple of years ago, and don't like them, but with this machine, I can dress them flat, and remove any glazing.

What kind of belts are you using to finish up with Ed?
 
For the most part, my finish belts are Norax....however, I don't like them on the surface grinder because of what I mentioned previously....for the surface grinder I like the Trizact belts. The only time I've found that it makes a lot of difference is at 400 and finer belts on the surface grinder.
 
Some further observations after some more time in front of the machine.

I have a serrated wheel, I'll bet this makes a difference.
I have a fine pole electromagnetic chuck, this definitely makes a difference. I can hold parts well.
I know how to block parts in using other pieces of steel, again this is part of holding the parts well.

I just did 20 more parts in just over an hour, this is amazing to me.
All of it was done with a single 60 grit Aluminum Oxide belt, and a P220 707E. (no need to go to A45 before heat treat)

I think switching to Ceramics for the 60 grit will help, as I could watch the leading edge of my grind creep further back on the belt as I went.
I did re-dress that belt after the 1st ten parts.

A 1" belt might be in order instead of the 2", just because of all the extra passes it takes to get a 2" belt off of the part.
My forearm feels it, and I was only there an hour.
I'll experiment with that before I cut my wheel down though!
 
I have really good luck with the 3M yellow belts at the 60 grit. I can never remember but I think they are the 977 Cubitron, they will last forever. Seems like I've been using the same one for a year.

From there I used to go to the 707E but more times than not anymore I go straight to the A45 gator belt.

I can use a 977 and an A45 gator forever it seems provided I watch what I'm doing and keep any wear even especially on the gator.

I'd like to know more about dressing the belt, do you do it just like a stone? If I did this I may go two years:les::biggrin:
 
I just got some 60g Blaze belts in.
Never had any of those before, we'll see how they do.

As far as dressing the belt goes, yes, I did it just like a stone.
However, RJ Martin turned me on to a trick that I will be using more often.

Use a 3M diamond hand pad to "scrub" away the high spot at the joint.
You end up with a low spot, but who cares.

I totally killed a P220 707E before I even got to touch steel with it using the single point.
A wasted $5 belt...
Tried his Idea over the weekend, and it worked GREAT

I still think the single point diamond is probably the way to go on gators and thick belts, but this pad idea of RJ's is outstanding, and really works like a charm, with no risk of ruining the belt.

Picture is one Mr. Martin sent me so I could understand what he was talking about...
 

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Hey, this whole business about surface grinding has been killing me lately. I just received a bunch of 154cm that needs to be ground and there is no other way to do it (and still make my margin). My production is getting to the point where I have no choice but to buy a surface grinder. This looks like the thing to do but where do I find a belt surface grinder like yours?
 
Did you make the conversion frame yourself or did you buy it? I just got a surface grinder a few months ago but have not got around to wiring it in yet. It was a freebie, just needed a small repair and I want to convert this to belts as I use a friends now with stones and what a pain in the butt.
 
Did you follow the link Mike?

Which part needs more detail?

I'm not against it, I just thought I had it covered...
 
nice job on that conversion...are you still favoring a 1" wheel?
Dave and I were talking about that today and it makes sense. Especially since 2" wheels are hardly ever very flat..
 
I am indeed Tracy, though I have only experimented with a 1" belt on the finishing grits.

Haven't tried any real hogging yet.
 
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