- Joined
- Dec 29, 2012
- Messages
- 394
I needed to cut a useable worm gear for a car door (window) mechanism
![P2232082s.jpg P2232082s.jpg](https://www.hobby-machinist.com/data/attachments/219/219989-6da9ab0741388d98a1eef895f5625f1c.jpg)
The motor and the enclosure of the mechanism are pretty solid but the plastic gear gave up making it useless.
![P2232075s.jpg P2232075s.jpg](https://www.hobby-machinist.com/data/attachments/219/219990-077fdb19cc1f627dc69de066ae134da2.jpg)
I intent to use it for a new project and I need a new metal worm gear to replace the plastic one. To machine it I need a simple dividing head which I do not own! To solve the problem I made a simple dividing head that uses gears as the index. Thus, the number of teeth on the back gives you the same number at the front.
To expand the indexing range I intent to use all gears provided by my mini lathe. My minilathe has a wide range of gears (20, 30, 35, 40, 45, 50, 55, 57, 60, 65, 80) so I can cut gears with a variety of teeth: 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 19, 20, 25, 30, 35, 40, 45, 50, 55, 57, 6 0, 65, 80.
First lets see what car industry offers ready made for that job!
![Column1.jpg Column1.jpg](https://www.hobby-machinist.com/data/attachments/219/219991-5c15b3fb8a58c6602f0a9c6f820d6eca.jpg)
Yes! That is a motor assisted steering wheel column.
It offers a section that is very convenient for the job.
![P3102126s.jpg P3102126s.jpg](https://www.hobby-machinist.com/data/attachments/219/219992-d6d038265e1dc46d7c0cb943af35c081.jpg)
After machining the shaft at steering wheel end, I made it support 8mm and 12 mm (mini lathe) indexing gears.
![P3102132s.jpg P3102132s.jpg](https://www.hobby-machinist.com/data/attachments/219/219993-b24479f6900b6c4188fa8799ff4242b9.jpg)
I also made a 20x1mm large nut to secure the shaft to the indexer body.
![P3102135s.jpg P3102135s.jpg](https://www.hobby-machinist.com/data/attachments/219/219994-ff751b154d4f1c6a2443089ab54246bd.jpg)
An adaptor to support 8mm hole gears
![P3102139s1.jpg P3102139s1.jpg](https://www.hobby-machinist.com/data/attachments/219/219995-a4b3c8954e368a9cf7ae5a588e2f2c81.jpg)
![P3102140s.jpg P3102140s.jpg](https://www.hobby-machinist.com/data/attachments/219/219996-44dcbfb44f2568846b100c5a4e4181d2.jpg)
A thick washer to secure 12 mm gears
![P3102137s.jpg P3102137s.jpg](https://www.hobby-machinist.com/data/attachments/219/219997-f23b96ac3787ba6dd5808482fbbe075b.jpg)
![P3102138s.jpg P3102138s.jpg](https://www.hobby-machinist.com/data/attachments/219/219998-268ecd797875cd275349378ce593d528.jpg)
I machined a 55cm recess at the other end of the shaft to fit a 3” chuck
![P3102128s.jpg P3102128s.jpg](https://www.hobby-machinist.com/data/attachments/219/219999-a531740c406d7b678a446ec5af14e6ab.jpg)
And welded 3 steel extensions at the back of the shaft plate to secure the chuck in place
![P3102133s.jpg P3102133s.jpg](https://www.hobby-machinist.com/data/attachments/220/220000-7026bb07f91276b5bdaddda894592e0e.jpg)
Dividing head ready!
![P3102122s1.jpg P3102122s1.jpg](https://www.hobby-machinist.com/data/attachments/220/220001-f93357969a61a12a042e474173c02a99.jpg)
All I need now is an index finger stop. Something simple…
![P3052086s.jpg P3052086s.jpg](https://www.hobby-machinist.com/data/attachments/220/220002-6f50e312f39ddef659ad847c0cd9c417.jpg)
Made using a few angle bars and a spring
![P3102122s2.jpg P3102122s2.jpg](https://www.hobby-machinist.com/data/attachments/220/220003-13d536cc4ff67ac568618f0a88b4f6d8.jpg)
![P3052085s.jpg P3052085s.jpg](https://www.hobby-machinist.com/data/attachments/220/220004-960bc86979330635caa865fd9fad7db6.jpg)
Now I can copy this peculiar plastic worm gear to a bronze one.
![8deggear.jpg 8deggear.jpg](https://www.hobby-machinist.com/data/attachments/220/220005-4f99f27e74005188eb4759f66400a3e0.jpg)
I secured the indexer to the mill vice at 8deg angle.
![8deg inclination.jpg 8deg inclination.jpg](https://www.hobby-machinist.com/data/attachments/220/220006-41c85c45f5d8925e9d6eb8aaafa22408.jpg)
Chose the appropriate gear cutter 0.5mod, 20 deg. #8 (>135 teeth)
![P3072101s.jpg P3072101s.jpg](https://www.hobby-machinist.com/data/attachments/220/220007-75ab27d92d473bc3412bebfa8c52420b.jpg)
Prepared the bronze blank on the lathe
![P2232073s.jpg P2232073s.jpg](https://www.hobby-machinist.com/data/attachments/220/220008-d8684bff1795b27862217a6491aca9d5.jpg)
And cut the gear
![P3052089s.jpg P3052089s.jpg](https://www.hobby-machinist.com/data/attachments/220/220009-bbdab9c49b6ed8ecd4e45476f25b787d.jpg)
It looks nice
![P3072099s.jpg P3072099s.jpg](https://www.hobby-machinist.com/data/attachments/220/220010-1b62e07334777efa586b5f933834bd08.jpg)
Fits nicely
![P3072096s.jpg P3072096s.jpg](https://www.hobby-machinist.com/data/attachments/220/220012-31712bc3f8b077a6ceef6f35d719efbc.jpg)
And works nicely
![P3072092s.jpg P3072092s.jpg](https://www.hobby-machinist.com/data/attachments/220/220013-67c56886e00c1661983940d717047fa9.jpg)
Thanks for reading
Petros
![P2232082s.jpg P2232082s.jpg](https://www.hobby-machinist.com/data/attachments/219/219989-6da9ab0741388d98a1eef895f5625f1c.jpg)
The motor and the enclosure of the mechanism are pretty solid but the plastic gear gave up making it useless.
![P2232075s.jpg P2232075s.jpg](https://www.hobby-machinist.com/data/attachments/219/219990-077fdb19cc1f627dc69de066ae134da2.jpg)
I intent to use it for a new project and I need a new metal worm gear to replace the plastic one. To machine it I need a simple dividing head which I do not own! To solve the problem I made a simple dividing head that uses gears as the index. Thus, the number of teeth on the back gives you the same number at the front.
To expand the indexing range I intent to use all gears provided by my mini lathe. My minilathe has a wide range of gears (20, 30, 35, 40, 45, 50, 55, 57, 60, 65, 80) so I can cut gears with a variety of teeth: 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 19, 20, 25, 30, 35, 40, 45, 50, 55, 57, 6 0, 65, 80.
First lets see what car industry offers ready made for that job!
![Column1.jpg Column1.jpg](https://www.hobby-machinist.com/data/attachments/219/219991-5c15b3fb8a58c6602f0a9c6f820d6eca.jpg)
Yes! That is a motor assisted steering wheel column.
It offers a section that is very convenient for the job.
![P3102126s.jpg P3102126s.jpg](https://www.hobby-machinist.com/data/attachments/219/219992-d6d038265e1dc46d7c0cb943af35c081.jpg)
After machining the shaft at steering wheel end, I made it support 8mm and 12 mm (mini lathe) indexing gears.
![P3102132s.jpg P3102132s.jpg](https://www.hobby-machinist.com/data/attachments/219/219993-b24479f6900b6c4188fa8799ff4242b9.jpg)
I also made a 20x1mm large nut to secure the shaft to the indexer body.
![P3102135s.jpg P3102135s.jpg](https://www.hobby-machinist.com/data/attachments/219/219994-ff751b154d4f1c6a2443089ab54246bd.jpg)
An adaptor to support 8mm hole gears
![P3102139s1.jpg P3102139s1.jpg](https://www.hobby-machinist.com/data/attachments/219/219995-a4b3c8954e368a9cf7ae5a588e2f2c81.jpg)
![P3102140s.jpg P3102140s.jpg](https://www.hobby-machinist.com/data/attachments/219/219996-44dcbfb44f2568846b100c5a4e4181d2.jpg)
A thick washer to secure 12 mm gears
![P3102137s.jpg P3102137s.jpg](https://www.hobby-machinist.com/data/attachments/219/219997-f23b96ac3787ba6dd5808482fbbe075b.jpg)
![P3102138s.jpg P3102138s.jpg](https://www.hobby-machinist.com/data/attachments/219/219998-268ecd797875cd275349378ce593d528.jpg)
I machined a 55cm recess at the other end of the shaft to fit a 3” chuck
![P3102128s.jpg P3102128s.jpg](https://www.hobby-machinist.com/data/attachments/219/219999-a531740c406d7b678a446ec5af14e6ab.jpg)
And welded 3 steel extensions at the back of the shaft plate to secure the chuck in place
![P3102133s.jpg P3102133s.jpg](https://www.hobby-machinist.com/data/attachments/220/220000-7026bb07f91276b5bdaddda894592e0e.jpg)
Dividing head ready!
![P3102122s1.jpg P3102122s1.jpg](https://www.hobby-machinist.com/data/attachments/220/220001-f93357969a61a12a042e474173c02a99.jpg)
All I need now is an index finger stop. Something simple…
![P3052086s.jpg P3052086s.jpg](https://www.hobby-machinist.com/data/attachments/220/220002-6f50e312f39ddef659ad847c0cd9c417.jpg)
Made using a few angle bars and a spring
![P3102122s2.jpg P3102122s2.jpg](https://www.hobby-machinist.com/data/attachments/220/220003-13d536cc4ff67ac568618f0a88b4f6d8.jpg)
![P3052085s.jpg P3052085s.jpg](https://www.hobby-machinist.com/data/attachments/220/220004-960bc86979330635caa865fd9fad7db6.jpg)
Now I can copy this peculiar plastic worm gear to a bronze one.
![8deggear.jpg 8deggear.jpg](https://www.hobby-machinist.com/data/attachments/220/220005-4f99f27e74005188eb4759f66400a3e0.jpg)
I secured the indexer to the mill vice at 8deg angle.
![8deg inclination.jpg 8deg inclination.jpg](https://www.hobby-machinist.com/data/attachments/220/220006-41c85c45f5d8925e9d6eb8aaafa22408.jpg)
Chose the appropriate gear cutter 0.5mod, 20 deg. #8 (>135 teeth)
![P3072101s.jpg P3072101s.jpg](https://www.hobby-machinist.com/data/attachments/220/220007-75ab27d92d473bc3412bebfa8c52420b.jpg)
Prepared the bronze blank on the lathe
![P2232073s.jpg P2232073s.jpg](https://www.hobby-machinist.com/data/attachments/220/220008-d8684bff1795b27862217a6491aca9d5.jpg)
And cut the gear
![P3052089s.jpg P3052089s.jpg](https://www.hobby-machinist.com/data/attachments/220/220009-bbdab9c49b6ed8ecd4e45476f25b787d.jpg)
It looks nice
![P3072099s.jpg P3072099s.jpg](https://www.hobby-machinist.com/data/attachments/220/220010-1b62e07334777efa586b5f933834bd08.jpg)
Fits nicely
![P3072096s.jpg P3072096s.jpg](https://www.hobby-machinist.com/data/attachments/220/220012-31712bc3f8b077a6ceef6f35d719efbc.jpg)
And works nicely
![P3072092s.jpg P3072092s.jpg](https://www.hobby-machinist.com/data/attachments/220/220013-67c56886e00c1661983940d717047fa9.jpg)
Thanks for reading
Petros