SIMPLE DIVIDING HEAD FROM A CAR STEERING COLUMN

[petcnc]

Simple and very effective, nicely done.

Thanks!

I like the part where you are using the old gear to make the new one.

...Like most of us here...

Very clever Petros. I always look forward to your posts. Mike

Thank you mike

Awesome Petros, inspiring indeed, wish I could give you more than one 'like'.

One is enough for me! Thank you!!!

 

[petcnc]

Great idea. I have thought about doing something similar to this. With google Sketchup you can divide a circle into as many equal parts as you need for teeth on your gear.

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This circle has been divided into 72 parts. You can also divide the circle by an odd number, 39 or 13 or whatever you want.


Print this out and glue it to a flat plate. You would need a some kind of clamp to keep the plate from turning. Using as large of diameter for the circular plate as you can minimizes any error that you may have in lining up the lines with a pointer. I thought of using an 8" diameter plate.

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Rough sketches of what I have thought of making. Just a concept and needs refinement and further thought on the details. Another project for another day.

Nice idea!
But building it I feel like re-inventing the wheel as I usually have to copy a gear and not make one from scratch!
I intend to make one indexer controlled by a microprocessor so you can set the angle, teeth etc and it will signal a stepper motor for full rotation accuracy.
I found plenty of info on the subject and I started collecting parts!
Stay tuned I will publish it when I will start making it

 

[chips&more]

Now that's using your noodle!

 

[rpmMan]

Nice work!! I am surprised that the index latch is able to hold it securely while machining...

rich

 

[petcnc]

[QUOTE="Nice work!! I am surprised that the index latch is able to hold it securely while machining... " QUOTE]

I tested by hand and it needed some force to dissengage from the teeth.
I had no problem in milling it as there are no vertical forces involved (Z is locked). On the other hand the 8 deg. inclination was not enough to create problems due to forcing the gear to rotate and/or jump a tooth.
I might was in luck also and the spring I chose from the scrap box was strong enough...
I dont know!!

 

[tjb]

I needed to cut a useable worm gear for a car door (window) mechanism

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The motor and the enclosure of the mechanism are pretty solid but the plastic gear gave up making it useless.

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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!

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Yes! That is a motor assisted steering wheel column.
It offers a section that is very convenient for the job.

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After machining the shaft at steering wheel end, I made it support 8mm and 12 mm (mini lathe) indexing gears.

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I also made a 20x1mm large nut to secure the shaft to the indexer body.

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An adaptor to support 8mm hole gears


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A thick washer to secure 12 mm gears


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I machined a 55cm recess at the other end of the shaft to fit a 3” chuck

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And welded 3 steel extensions at the back of the shaft plate to secure the chuck in place

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Dividing head ready!

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All I need now is an index finger stop. Something simple…

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Made using a few angle bars and a spring

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Now I can copy this peculiar plastic worm gear to a bronze one.

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I secured the indexer to the mill vice at 8deg angle.

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Chose the appropriate gear cutter 0.5mod, 20 deg. #8 (>135 teeth)

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Prepared the bronze blank on the lathe

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And cut the gear

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It looks nice

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Fits nicely

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And works nicely

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Thanks for reading

Petros

Beautiful work, Petros. Very creative.

Regards,
Terry

 

[PHPaul]

Pure genius!

I've scanned a couple of different threads with titles like "A dividing head anybody can build" and have come to the conclusion that I'm obviously not "anybody" because I wouldn't have a whisker of a chance of building something like that, even if I HAD the tools. I'm the rankest of rank amateurs and at 67, it's not likely I'll be around long enough to develop the necessary skills.

Your device, I think I could build successfully.

As soon as I scrape together the money for a mill that is.

Bookmarked...

 

[dbq49]

Very interesting to see your construction process and to see the part in place. I come back to thinking that plastic was used for what reason? As most gearing is suppose to have one material as the sacrificial material to keep something else from being destroyed. If not from another plastic, what about a brass gear? Just wondering what will break next????
DBQ49er

 

[mickri]

I need to replace two gears to be able to cut metric threads through the QCGB on my lathe. I could just buy them but what fun would that be. The need to cut metric threads is a ways in the future. So no rush right now to be able to make gears.

 

[petcnc]

Very interesting to see your construction process and to see the part in place. I come back to thinking that plastic was used for what reason? As most gearing is suppose to have one material as the sacrificial material to keep something else from being destroyed. If not from another plastic, what about a brass gear? Just wondering what will break next????
DBQ49er

This plastic gear meshes (through some rubber material that works as cushion), to another plastic spool where the steel cables wind up on.

This is also a usual failure. Half of the mechanisms I was given were replaced because of this!
I have no intention to use it as it was used! I just need a slow-turning 12v DC mechanism for a different project and the plastic gear was the best candidate for failure!
The funny thing to all these mechanisms is that failures do not happen due to normal wear & tear but there is always a part "designed" to fail prematurely. This was the case with the steering column and with the window opening/closing mechanism used here!
If all sub systems of the mechanisms were solid then in a window blockage situation you would have a blown electric fuse, not the mechanism itself.
A friend of mine that owns a car repair shop, provides me with plenty of failed car devices and when I examine them I feel its a big waste of materials to throw them away/recycle for a part that it was obvious that it will fail VERY soon in normal operation.
I have seen beautiful (and very expensive) air pumps for air suspension cars to be replaced because of an o-ring failure as there is no repair kit available on the market to fix the leak!!!
I'm afraid that we are the last generation that repairs things. The tendency is for the market to develop "fitters" that replace the part for a new one and do not bother in fixing anything!

petros