Grinding Belt Speeds

T

Tinker Simpleton

Joined
Jan 13, 2006
Messages
84
How slow is too slow for a belt?

I got my home made grinder going. I'm using pulleys to change speeds and I'm on my fastest speed and I still can't make a spark on ATS-34. I'm afraid it's still too slow and the belts are working too hard to make cuts. However, I also like that it takes some time as I'm new to this.

Any thoughts would be greatly appreciated. Thanks!
 
I rarely get sparks grinding ATS-34. I don't know what too slow is, I use belts at whatever speed I'm comfortable with for the operation.
 
My grinder is also homemade, it has 4 speed variable pulleys. At the fastest speed I barely get any spark from my RWL34 stock (it is basically same steel). If the grinder doesn't cut well (you'll notice if it is not cutting even if you are novice, especially these powder steels grinds like butter compared to D2 or other SS stock with sharp belts) there are 5 main reasons I can think of.
1. You press the steel very lightly to belt, press the blade a bit harder,
2. Belt is dull, change the belt with the sharper one
3. Pulley belt is loose and the motor cannot transfer enough power to drive wheel. Tighten the pulley belt by putting more distance between motor pulley and grinder pulley...
4. Your steel stock is not annealed, it is normal if it is hardened state.
5. Your grinder is running real slow apparently. Try to enlarge the pulley diameter of your motor pulley disc or to lower the diameter of grinder pulley.

Here is my setup:
DSC01604%20%28Large%29.JPG
 
My grinder runs at warp speed and get very little sparks wth ATS - 34.
 
As mentioned, "sparks" don't really mean anything... I guess the real question is: Is it removing steel?

-Mark
 
It only started removing material when I put the belts on with the rough side out. I thought the rough side made it easier for the motor to turn the belt.

It cuts just fine, and I'm inclined to leave it as it is. A pull of a blade across the belt takes enough material off for me, so I'm thinking I should be happy with that. And, between switching grits and coloring the blade with Magic Marker, it seems to do a good job of removal then, too.

Overall I'm VERY happy with my new grinder. It took me quite a while to figure out how in THE HELL to get it to track straight. I finally ended up tacking up the parts, turning it on, and adjusting until I got it where I wanted it before I welded it.

I told my wife I can do in five minutes now what used to take 3/4 to one hour by hand.
 
balibalistic said:
Push some TI into 'er :) if it dont spark....wel,you need more juice :thumbup:
Click to expand...

Just keep a fire extinguisher handy.....


Just out of curiosity, what grit belt are you starting with? I generally use 36 and 40 grit for roughing, and start at 60 for the bevels. After the bevels are close, I'll switch over to trizact belts and get everything cleaned up.
 
Whoo..,you want the rough side out,buddy. thats the abrasives that removes steel.your not going to get far trying to grind with the backing.
 
Tinker Simpleton said:
How slow is too slow for a belt?

I got my home made grinder going. I'm using pulleys to change speeds and I'm on my fastest speed and I still can't make a spark on ATS-34. I'm afraid it's still too slow and the belts are working too hard to make cuts. However, I also like that it takes some time as I'm new to this.

Any thoughts would be greatly appreciated. Thanks!
Click to expand...

Please supply the following:
motor RPM
motor pulley diameter
drive shaft pulley diameter
drive wheel size
 
Bali:

I know how a belt goes on :). Just a little joshing going on there.

Fitzo:

2" belt drive wheel
1750 rpm
4" motor pulley
2" drive wheel pulley
 
Tinker Simpleton said:
Bali:

I know how a belt goes on :). Just a little joshing going on there.

Fitzo:

2" belt drive wheel
1750 rpm
4" motor pulley
2" drive wheel pulley
Click to expand...

As far as I know it is 1831 ft per min belt speed. If my calculation is right it is somewhat slow side...
 
If I managed to work my calculator correctly, that runs the belt at 1832 surface feet per minute. I run my two variable speeds such that they deliver 4500 and 4200 SPFM at 100%. I do delicate grinding at 30-40%, so lets say approx 1500 SPFM. Some people run their grinders up at 5000+ SPFM for heavy stock removal.

I would suggest you change your drive wheel to 4". That will work better when grinding profiles or bevels and allow you to slow it down for finish work and delicate grinding. Not to mention, some of the expensive ceramic abrasives work much better at higher rates.

Hope that helps.
 
I run mine most of the time at 4000SFM and get a guud bunch of sparks. but i can grind CPM-154 CM at full speed and not get any sparks. i just end up with a pile of what looks like steal wool :D
 
This one was funny too... I removed the name as an act of mercy...

thanks, i was looking at some s30v steel sold by the inch, so you just grind it with the right tools and polish it and kazzam a knife blade??
Click to expand...

The difference is, I think he really meant it. Egads, I wish it was that easy :D I asked the poster if I could use it in my sig line but he never responded, so I didn't :(

galadduin, is that a buffing wheel in your drill press? How's that working for you?
 
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Bwahahaha, I went and looked and he sure did!! Thanks for the heads-up Mike :D

Hee hee... the "kazzam!" is the bestest part :D

Sorry to derail the thread with my asinine sense of humor guys :o
 
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