02/18/2000 I was making three brass nuts for the Steady Rest when I heard a sickening THUMP from the lathe. UHHH OWWW.... I thought. Hmm the motor is going but the chuck stopped spinning. GREAT! I broke the keyseat on the Motor Drive Gear. When I looked at it to figure out how bad it was, this is what I saw. |
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Plastic Drive Gear in three pieces |
Plastic Drive Gear Notice the air bubble on the Left side. |
Another air bubble. |
Air bubble on main piece. Better Lighting. |
Notice the clean fracture of the piece. |
Plastic Drive Gear after carefully using crazy glue. |
I started thinking.... Lathe down for a couple weeks to a couple months until gear ships in from CHINA... NOOOOO..... I'll make one!! After a couple minuites carefully gluing the peces back together so I could measure the gear. I sat down with Visio and made a drawing of the gear. I took a 1.5" disk of t6061 I had in the CHUNK pile. mounted it in the 3-jaw. Placed the glued gear on the motor. Crossed my fingers & turned the dish down to the proper size. Then mounted it it the 5C indexer. PROBLEM #1 - drive gear has 17 teeth. Lets see 360/17=21.1764 Degrees. OOOps.. Well 360/18 is 20 Degrees, So 18 teeth it is. UH OH, that changed the pitch diameter beause the tooth size cant change much without having the belt jump a tooth. Back to calculating.. I finally came up with numbers that looked correct. So I fired up the mill with the indexer mounted. cut 18 slots on the blank about .050" deep just in case. I then cut a keyway with a 5/32" endmill and tried the gear & belt together. It fit for a couple turns with out having a tooth fall out of sync. So I mounted it on the motor, Crossed my fingers and spun up the 7x10 at min. Not a sound out of place. So I spun it up to max no odd sounds. So if you break a gear have heart. If I can make one YOU CAN TOO!!! |
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New Drive Gear Oblique View. |
New Drive Gear Rear View. |
New Drive Gear Front and Above. |
New Drive Gear TOP View. |
New Drive Geari Side View. |
New Drive Gear Head on View. |
This page last updated 04/20/2000
You are Visitor number since 06/23/1999
All above images Copyright (c)1999
Ty Hoeffer