- Joined
- Jul 31, 2013
- Messages
- 314
Hi
+1
I think your stamping article would be very good.
Great job
+1
I think your stamping article would be very good.
Great job
-
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Tool and cutter grinder build
- Thread starter Mark_f
- Start date
The drive belt came today and I ran the grinder for the first time.
It is a bittersweet success. First the grinder runs great, BUT........ there are a couple issues to work out. The main one is the belt is too short and that makes it too tight when stretched onto the pulleys.
Let's start at the motor. The motor has plenty of power for grinding, but the starting torque is not real high. the belt is so tight the grinder cant start with out a little push. It seems once the belt warms up , the thing can start on its own and run fine. Now, this is my fault. I ordered this $20 belt off ebay and the service was excellent. I used a website belt length calculator to decide the belt size.
The calculator is set up for round pulleys like mine. You enter the pulley O.D. , the distance between the pulleys, the depth of the pulley groove, and they use a "stretch factor" and that number is 10.
When you plug the numbers in it gives you the cut length of the belt. It says use a 24 inch belt, so stupid me orders one.
Well , it is wayyyy too tight. I refigured the belt with the calculator and leave the stretch factor out and it gives a 26"
belt. I ran a tape measure around the pulleys and the distance is 26 inches. Imagine that!!!!!!
So now , I have to order another $20 belt. It will run fine with the right belt.
Now ... the spindle..... I ran the spindle for 30 minutes. It runs quiet and smooth. the housing is just warm to the touch. The spindle inside the cavity where the collet will set is hot. I am pretty sure this is because that is the spot where the oil seal rubs on the shaft. The oil seals were specified at .875" I.D. I measured them with calipers ( as best you can measure a rubber seal ) and they seemed about .020" under size. I think this is why that one spot gets hot. If so, the seal may wear in some. I noticed assembling the spindle that the oil seals put a pretty good drag on the shaft. The bearing areas are not hot.
So..... all in all this is a success except for the belt issue. I am working on a hair brained, red neck idea
to solve the belt issue , but I ain't gonna say what it is unless it works... then I'll tell ya.
There are still some details and a few small parts to make before we start grinding tools so I will keep going and posting the progress. Keep watching folks ..... we getting close now.
It is a bittersweet success. First the grinder runs great, BUT........ there are a couple issues to work out. The main one is the belt is too short and that makes it too tight when stretched onto the pulleys.Let's start at the motor. The motor has plenty of power for grinding, but the starting torque is not real high. the belt is so tight the grinder cant start with out a little push. It seems once the belt warms up , the thing can start on its own and run fine. Now, this is my fault. I ordered this $20 belt off ebay and the service was excellent. I used a website belt length calculator to decide the belt size.
The calculator is set up for round pulleys like mine. You enter the pulley O.D. , the distance between the pulleys, the depth of the pulley groove, and they use a "stretch factor" and that number is 10. When you plug the numbers in it gives you the cut length of the belt. It says use a 24 inch belt, so stupid me orders one. Well , it is wayyyy too tight. I refigured the belt with the calculator and leave the stretch factor out and it gives a 26" belt. I ran a tape measure around the pulleys and the distance is 26 inches. Imagine that!!!!!! So now , I have to order another $20 belt. It will run fine with the right belt.Now ... the spindle..... I ran the spindle for 30 minutes. It runs quiet and smooth. the housing is just warm to the touch. The spindle inside the cavity where the collet will set is hot. I am pretty sure this is because that is the spot where the oil seal rubs on the shaft. The oil seals were specified at .875" I.D. I measured them with calipers ( as best you can measure a rubber seal ) and they seemed about .020" under size. I think this is why that one spot gets hot. If so, the seal may wear in some. I noticed assembling the spindle that the oil seals put a pretty good drag on the shaft. The bearing areas are not hot.
So..... all in all this is a success except for the belt issue. I am working on a hair brained, red neck idea
to solve the belt issue , but I ain't gonna say what it is unless it works... then I'll tell ya.There are still some details and a few small parts to make before we start grinding tools so I will keep going and posting the progress. Keep watching folks ..... we getting close now.
Would you like the Bonelle drawings I started with and based this machine on or my drawings of what I built which is very different in many areas?
- Joined
- Mar 19, 2014
- Messages
- 2,681
Mark, it sounds like you calculated correctly. When you figure the length for urethane belting you factor in for ~10% stretch. Anyway, I have many yards of 5mm round urethane belting. Can’t tell from your pic, but maybe a tad smaller, but the price is right. If you want some, PM me and I will mail you whatever you need with welding instructions (it’s very easy to do)…Good Luck, Dave.
B
Bill Gruby
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Register Today
Mine had a hard start at first Mark. Once the bearings were run in for a time I no longer needed to give it help. Wait it out. Let it break in.
"Billy G"
"Billy G"
OK.... my red neck hair brained idea half a**** worked.
It gave me the solution anyway. I needed to stretch this belt. Boiling water didn't work, so i stretched it over a piece of 2 x 4 and put it in the oven ( ya'll can stop laughing now ) it worked. it stretched the belt. But stupid me in my desperation made two mistakes.
First, I should have stretched it over something round as the corners of the 2 x 4 put dents in the belt and it made it square instead of round. And it is now TOO BIG!. ( I mean it .. Stop laughing!) The square belt went thump..thump...thump...thump.. every time a corner went around the pulley until it flew off. So, I measure this square belt and it is 26 1/2" instead of the 24 I started with.
OK.. I got me another hillbilly idea ( my dad would be so proud) I cut the four corners out of the belt and melted the ends of the pieces over the flame on mama's gas range and stuck them back together. I sanded the joints smooth with my Dremel with a little drum sander. My belt is now 25 1/4" and fits really good. Just 3/4" of stretch. The pulleys turn waaayyyy more easier without all that tension.
It ran great for 20 minutes until one of my joints let go and the belt flew across the room. ( my dog looked at me like I am stupid and left the room. Probably don't want to get hit with the flying belt cause she got all upset)
The conclusion is a 25 1/4" belt will solve most of my problems.
It gave me the solution anyway. I needed to stretch this belt. Boiling water didn't work, so i stretched it over a piece of 2 x 4 and put it in the oven ( ya'll can stop laughing now ) it worked. it stretched the belt. But stupid me in my desperation made two mistakes. First, I should have stretched it over something round as the corners of the 2 x 4 put dents in the belt and it made it square instead of round. And it is now TOO BIG!. ( I mean it .. Stop laughing!) The square belt went thump..thump...thump...thump.. every time a corner went around the pulley until it flew off. So, I measure this square belt and it is 26 1/2" instead of the 24 I started with. OK.. I got me another hillbilly idea ( my dad would be so proud) I cut the four corners out of the belt and melted the ends of the pieces over the flame on mama's gas range and stuck them back together. I sanded the joints smooth with my Dremel with a little drum sander.
My belt is now 25 1/4" and fits really good. Just 3/4" of stretch. The pulleys turn waaayyyy more easier without all that tension. It ran great for 20 minutes until one of my joints let go and the belt flew across the room.
( my dog looked at me like I am stupid and left the room. Probably don't want to get hit with the flying belt cause she got all upset)The conclusion is a 25 1/4" belt will solve most of my problems.