Surface Grinder Conversion

T4Texas

Active Member
Well, after six months or so of reading and digesting forum threads, looking at other conversions, talking to others that have done the conversion and finally collaborating with Craig Brewer my surface grinder conversion is done! :biggrin:

I ordered my contact wheel from Sunray. It is six inches in diameter, one and one quarter inches wide with a durometer rating of 60D which makes it probably a little harder than 100 on the "A" scale. Like Dave of Great Lakes, I ordered it with the X-Tread pattern. I'm running one inch wide belts.

Craig did most of the mechanical design and all of the welding and fabricating. We finished putting it all together Wednesday and did a test run. From the first flip of the switch it tracked perfectly and we were both amazed at the quality of the finish.

Many thanks to all that provided information for this project and special thanks to Craig for all his help.

Ted
 

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Troop

Well-Known Member
Wow! That looks great. I'm gonna have to get me one of these one of these years.
 

Calvin Robinson

Moderator Christian Forum
I know you are going to enjoy using that surface grinder much more now since you converted it to a belt type, looks good. Do you split those belts or buy one inch belts? If you split them can you tell us how you do it? I would like to try that kind of belt on my surface grinder.
 

T4Texas

Active Member
Thanks guys! Travis, you put it on the list and I'll work on actually trying to make a knife as great looking as one of yours. Calvin, I split 2" belts with Tracy's handy belt splitter.
 

T4Texas

Active Member
CW, I don't know. Time will tell. I'm not positive but I believe I got this idea from one of Brian Fellhoelter's posts on this forum. Sounded like a good idea to me so I went with it. It can't hurt, it may help and the extra cost is minimal.
 

Craig

KNIFE MAKER
I will be happy when my wheel comes in so I can get mine finished. You should have a big gritty dust pile by now.

Good to see you got it up and going again.
 

Fellhoelter

Well-Known Member
I'm actually discovering that I don't like the wheel being wider than the belt.
Mine is wider, but it's because it is a 2" wheel for 2" belts, and I split them and run 1" belts.
I don't like it being wider because the belt edges are wearing little grooves in it, and I'll have to re-dress it because of this.
Tracy sells an awesome splitter.

I even hit the inside edges of the belt with a diamond file when I turn it on to try and minimize this.

I'm getting ready to re-build my arm already, and I think I'm going to cut my wheel down to just a little under 1", and give that a try.
I'll just undercut the rubber 1st to see if it works well, and if it doesn't, I can re-dress the wheel a little and it'll just be a little smaller in diameter.
I'm not certain what to expect from this, as a tiny bit of belt will be unsupported at the edge.

The rebuild is due to the fact that I really didn't expect to like the belt setup, so I built it to work for a little while, and not to last.
Turns out I love it, so it needs a little tweak.
I also got a large diameter tracking wheel from Travis Wuertz at the hammer in last weekend.
I like the idea of that larger idler spinning at a slower RPM 2 - 1/2 feet up that arm...

Your build looks good, and interesting, and heavy...
My concern would be hanging that much weight off of the spindle.
I don't know that it's a problem, or even really think that it's one, but these machines aren't designed to hold weight.
So, my theory was to build one as light as I could, and keep the weight as centered as I could.
 

Sampson knifeworks

Well-Known Member
I'm actually discovering that I don't like the wheel being wider than the belt.
Mine is wider, but it's because it is a 2" wheel for 2" belts, and I split them and run 1" belts.
I don't like it being wider because the belt edges are wearing little grooves in it, and I'll have to re-dress it because of this.
Tracy sells an awesome splitter.

I even hit the inside edges of the belt with a diamond file when I turn it on to try and minimize this.

I'm getting ready to re-build my arm already, and I think I'm going to cut my wheel down to just a little under 1", and give that a try.
I'll just undercut the rubber 1st to see if it works well, and if it doesn't, I can re-dress the wheel a little and it'll just be a little smaller in diameter.
I'm not certain what to expect from this, as a tiny bit of belt will be unsupported at the edge.

The rebuild is due to the fact that I really didn't expect to like the belt setup, so I built it to work for a little while, and not to last.
Turns out I love it, so it needs a little tweak.
I also got a large diameter tracking wheel from Travis Wuertz at the hammer in last weekend.
I like the idea of that larger idler spinning at a slower RPM 2 - 1/2 feet up that arm...

Your build looks good, and interesting, and heavy...
My concern would be hanging that much weight off of the spindle.
I don't know that it's a problem, or even really think that it's one, but these machines aren't designed to hold weight.
So, my theory was to build one as light as I could, and keep the weight as centered as I could.

Hello,
I was wondering why everybody is going with the 1" wide belts? Is the 2" too much for the surface grinder to handle, pressure per square inch thing? Building one of these is my next project, but I have to sell a motorcycle first!
Sincerely,
Clint
 

Fellhoelter

Well-Known Member
I'm frugal, I'm lazy, and my table is small.

There's my reasons for using 1" !!!

Frugal, I get 2 belts for the price of 1.

Lazy, with a 1" belt there's just that many fewer times I have to cross feed the Y axis. (You don't just plunge straight down on the full blade width, you run the machine the same as if it had a stone on it, with the exception of the Z feed increments.)

I only have a 6" X 12" table, and not much more travel than that, so a 2" belt really eats up a lot of real estate.
Remember, I need enough travel for my belt to be able to run off of the part in both directions in the Y axis, because you do NOT plunge straight down on the blade.

I get equally good results and stock removal rates with the 1" as I do with 2", so to me, in my shop, it makes more sense to use a 1" belt.
I hold tolerances to the tenths, remove stock FAST, and get a nice finish...
 

BossDog

KnifeDogs.com & USAknifemaker.com Owner
Staff member
Hello,
I was wondering why everybody is going with the 1" wide belts? Is the 2" too much for the surface grinder to handle, pressure per square inch thing? Building one of these is my next project, but I have to sell a motorcycle first!
Sincerely,
Clint

Clint,
I've asked this question for years. The consensus answer I have heard is that a 1" belt wears fairly evenly across the width vs. a 2" belt. The 2" has you chasing tolerances as you bring the wheel back and forth across the metal being ground. The other thing I've heard is that it is easier to get a 1" wheel flat than a 2" wheel.
 

Les George

Admin - Founding Member
I just tried a 60 grit at 1 inch wide the other day. Yeah, I like that better.... I have still been running the gator betls at 2 inch though, I should probably cut some of them down too...

The belt conversion is better than pockets on jeans! :)
 

Josh Dabney

Moderator
Great topic guys !

Picked up a Boyar-Schultz 612 Challenger this week and plan to do a belt conversion also.

I had in mind going with a 1 1/4" wheel also for use with 1" belts

Fellhoetler- Do you think a harder contact wheel would stop the belt wear ? Could you give us an update as to how the belt being wider than the wheel goes once you try that out.

Thanks Alot, Josh
 

Josh Dabney

Moderator
Since it's on topic I thought I'd one more question-

My grinder is direct drive with a Lovejoy Spider Coupling to connect the motor to the spindle and the spider is completely shot. I already pulled the motor and the old spider was blue and very hard.

These are my replacement options- one is Buna-N (rubber) the other is Urethane (hard)

I'm thinking that Buna N is the way to go because it will be a little shock absorbing for start-up and assist in cancelling any vibration from the motor being passed to the spindle.

The center of the spider was still there and was hard probably more like the Urethane version but I have no idea if that was original equipment or has been replaced .

Any insight will be appreciated !

-Thanks, Josh


http://www.use-enco.com/CGI/INSRIT?PMAKA=990-4042&PMPXNO=3025770&PARTPG=INLMK32

http://www.use-enco.com/CGI/INSRIT?PMAKA=619-3475&PMPXNO=16721201&PARTPG=INLMK32
 

T4Texas

Active Member
Josh

I have no idea at all on this one! Wish I could help but maybe someone else has some insight on this.
 

Fellhoelter

Well-Known Member
I'm running a 90 duro wheel, so pretty hard...

I'd use the BunaN myself Josh, but that's what I have used in other applications.

We used Lovejoys a lot for power transmission in the oilfields, and the rubber takes up a lot of vibration.
 
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