The tachometer came in yesterday. Now, I’m ready to start working on determining the pulley sizes.
I did read, understand and follow all the instructions that came with the my tachometer. After putting the refective sticker on the flywheel of the motor, I was able to determine that the maximum speed of the motor is 6200 RPM’s. That speed is about twice as fast as I need it so my pulley ratio should be around 1:2. I found a pulley calculator online and I have an idea of the sizes I want for the pulleys.
Now we get to the pulleys. I did consider cutting a V shape groove in the drive pulley but I am now oping to put a V pulley on the motor’s flywheel. I found some 3/4” bore pulleys that will work fine so I needed to work on attaching this pulley. I tried to file the built-in pulley on the flywheel but I found that the pulley was winning that battle. So, as most of you would do, I went to Harbor Freight for my free tarp. At HF, a revelation came to me… use my angle grinder to rough out the flywheel and finish it off with a file. I did just that. Here is the results:
I took the flywheel off the motor I planned to use on the lathe and mounted it on the other treadmill motor I have. The grinder worked very well and then disaster struck. I told you in the earlier blog that if you reverse the motor there was a chance the flywheel would come off. It will; especially if you have taken the set screw out. That sucker hit the floor; spinning at an incredible speed. It ran across the shop and into the bathroom hitting the toilet and cracking the base. This is what I envisioned my face looked like as the free flywheel streaked across the floor:
And thinking back, it is exactly what I looked like. 5 minute epoxy. I hope I got it repaired.
The business that sells pulleys will be open in the morning so I’m off to buy pulleys. More tomorrow.
-- The more skilled you are at something, the worse you are at it when someone is watching.
3 comments so far
TraylorPark
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213 posts in 2569 days
#1 posted 01-03-2015 04:03 AM
Great Scott!! Sorry to hear about the issues, but thanks for the laugh. Hopefully you get it all sorted out, and when you do I might hit you up on some details. I’m planning on putting a treadmill motor on a lathe as well. Good luck.
Zach
-- --Zach
mickeybob
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9 posts in 2204 days
#2 posted 01-09-2015 09:55 PM
That made me think of a game we played when I was in the navy. We called it “Danger Nut” ( I know, I know). But basically you put a large nut on the end of a screwdriver and then use 700 psi air blowing past one side to spin it then flick it off the end. With everything being made of metal and the nut being irregularly shaped, it would take very unpredictable paths hence the name. I was funny at the time but I have to admit not one of my brighter activities.
Woodknack
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13543 posts in 3351 days
#3 posted 01-11-2015 04:43 AM
Nice solution. I lucked out with my first treadmill motor as it has a V groove pulley. But my 2nd motor is nearly identical to yours and I have debated what to do about it.
-- Rick M, http://thewoodknack.blogspot.com/
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