# Making change gears for my lathe



## tompas11 (Apr 20, 2011)

Needed some change gears for my Blomqvist lathe so I could do some threading.
At that time I did not own a milling machine, so what to do when you need some gears?
Well you take what you have in the shop and hope for the best.
So here we go...
I started with making four indexing plates. The sheet metal is 3mm thick and came originally from my old 3000 litres oiltank in the cellar. I did cut the tank up and saved the sheet metal some years ago. Now it was handy to have.
Anyway, then I drilled a totally of 861 3mm holes in the four plates. Puh!
Some kind of locking tool was needed, so lets make one!
Two flycutters was also made and a special attachment for the topslide.(And yes I am not a welder)
A special tool to hold the brass gear blank was then needed so I made that one to. (Aint that sweet?)
Everything was then bolted to the lathe and the rest was a piece of cake. 

I did make some gears in Delrin to. Tried to make some gears in steel also but that did not work out well because of heavy vibration. 
Here are some pics that might give you a hint how I managed to do the trick.


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## Old Iron (Apr 20, 2011)

It seems like where there is a need you find away. Very ingenues setup I never would have figured that one out.

Paul


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## pdentrem (Apr 20, 2011)

It is almost like a gear hobbing setup. Best part it uses the flexiblity of the division plates vs having to use another gear to make the gear.


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## ScrapMetal (Apr 20, 2011)

What did you use for indexing the holes that you drilled into the indexing plates?

Nice solution you came up with, by the way.

Thanks,

-Ron


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## tompas11 (Apr 21, 2011)

Hmm... I will try to explain.
For indexing the holes to the indexing plates I used a program called KyPlot (V 2.0 Beta 15).
It is a free charting program that looks a bit like Excel but do have more powerful charting capabilities. You just divide 360 degrees by the numbers of teeth required by the gear you want to make. Then you have a circle divided into x numbers of pie slices. Print it out in 1:1 scale, cut out the circle and glue it on the metal plate. Carefully center punch and drill. Done!


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## ScrapMetal (Apr 21, 2011)

Sweet! Simpler than I would have expected. I like that. 

-Ron


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## 8ntsane (Apr 21, 2011)

Yup
Now thats thinking outside the box, gotta love it.
How did the finished gear mesh up, any problems?

One must try the insane, to acheive the impossible,,Good job!


Paul 8)


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## MarkBall2 (Apr 21, 2011)

I like how you used the index plates to space the teeth acccurately. I did something similar for my Craftsman lathe, but I used a "pie chart" on the top with a pointer. Took me a while to get it done, but it did the job.

The single point tool works pretty good for cutting gears too. I used aluminum on mine.


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## tompas11 (Apr 22, 2011)

The finished gears meshed up pretty well. Maybe a little more noisy but that will decrease with
time as the gears are used. The gears made of Delrin run very smooth from start.


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## tompas11 (Apr 24, 2011)

> author=knudsen link=topic=1815.msg11693#msg11693 date=1303604077
> You do better gears than I do on my mill! 8)



Ha, ha, ha!
Thanks Knudsen for your kind words. I am flattered. ;D


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