# Change Gear Info Needed



## Billh50 (Dec 25, 2017)

Would anyone happen to know what the pressure angle is on the change gears for a HF mini-lathe ?
I want to make a couple gears for a project and need to match the change gears. So before I go looking for a gear cutter I need to know what the pressure angle is.


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## Bill Gruby (Dec 25, 2017)

. According to the parts list, all change gears are 1 Module pitch. No pressure angle is noted. Change gears are 80-35-90-30 and 100 TPI. These are for the #44859 8X12 Mini Lathe.

"Billy G"


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## Billh50 (Dec 25, 2017)

I have the 7x12 lathe. So it might be different. They only go up to an 80 tooth. And not sure if they are the same pitch or not.


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## Bill Gruby (Dec 25, 2017)

Looks like my next requisition are Pitch Gages. LOL


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## Billh50 (Dec 25, 2017)

LOL


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## Billh50 (Dec 25, 2017)

I found what I needed !
Took a bit of searching but found it.
The specifications for the gears used on the Mini-lathe are: module 1, 20° pressure angle, 8mm face width, and a 12mm bore with a 3mm wide by 1.4mm deep keyway.  Any gear that meets these specifications can be used on the lathe.


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## Billh50 (Dec 25, 2017)

Now I just have to see if I can find a set of cutters that I can afford. Anyone try the sets from China? I would only be cutting either plastics, brass or aluminum.


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## Ulma Doctor (Dec 25, 2017)

i have tested a couple chinese cutters on my Atlas MFC in mild steel, but they were not gear profile cutters.
they were sufficient for the testing, and i suspect they would hold up just fine in softer materials


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## Billh50 (Dec 25, 2017)

The Chinese and Russian sets are 1/2 the price. So may have to go with those in January.

I really miss having a whole toolroom for my personal use.


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## Ulma Doctor (Dec 25, 2017)

i have purchased Russian straight edges and some metric indicators.
the items i received were very high quality.
the test results were equal to mitutoyo, as far as the dial indicators were concerned.
the straightedges blued up straight as my grade A surface plate 
personally, i would lean the Russian tooling way for a couple extra Kopecks


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## chips&more (Dec 25, 2017)

For just a couple of gears, maybe think about just grinding a profile cutter and mounting it in a fly cutter. I do it all the time. And you can pierce out the blank with a slitting saw to relieve the work when using your homemade profile cutter. Just trying to save you $$$…Dave


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## Billh50 (Dec 25, 2017)

chips&more said:


> For just a couple of gears, maybe think about just grinding a profile cutter and mounting it in a fly cutter. I do it all the time. And you can pierce out the blank with a slitting saw to relieve the work when using your homemade profile cutter. Just trying to save you $$$…Dave


I would but I shake too much now. The profile would look real ugly.


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## chips&more (Dec 26, 2017)

Use the tool rest on your grinder. And use a Dremel mounted with a barrel stone. Also when doing it this way, no need to know what PA the mating gear(s) are. And is this for the change gears? You could probably get away with making the gears out of Derlin or aluminum. All this typing, you would have been done already and Happy New Year!


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## Billh50 (Dec 26, 2017)

I would need to make a tool rest first...LOL


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## RandyWilson (Dec 26, 2017)

What tooth counts are you after?


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## Billh50 (Dec 26, 2017)

I am going to make a 100 tooth gear.


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## rgray (Dec 26, 2017)

I believe the rule is all module gears are 20 deg. I'm sure there could be exceptions.
I have a few of the chineese gear cutters and they cut just fine.
Worst thing is the marking/labeling on them. Almost not there on the ones I have so keeping them identified is a problem.
Hang all the module ones on one hook, but then you need to know what # each is.
BTW a 100 tooth would take a #7 cutter.


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## RandyWilson (Dec 26, 2017)

Ah. 20:1 rather than the stock 16:1. Something that lathe can certainly use from a surface finish point of view. Have you measured to see if the banjo has enough travel? I'm sure the cover won't clear.


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## Billh50 (Dec 26, 2017)

I can make everything work. Even if I need to make a new cover.


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## RandyWilson (Dec 26, 2017)

Oh, I'm sure you will make it all work. I was just thinking that it is such an obvious untapped market, why doesn't one exist? They make odd tooth counts, and aluminum replacements, so why not a 100 tooth?  Clearance is my guess.


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## Billh50 (Dec 26, 2017)

Maybe...who knows. Was something I wanted for a finer feed. Plus I can use it to index the lathe 100 0r 200 times to scribe dials.


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## Billh50 (Dec 27, 2017)

I will be ordering the chinese cutters after January 3rd when my SS comes in. They won't be in til end of month or begining of Feb but that's ok as I need the weather to warm up a bit anyway.


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## Silverbullet (Dec 27, 2017)

Some of the China ones on. EBay are cheaper on the bang goods or the other one. Like $60 a set .


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## Billh50 (Dec 27, 2017)

Just ordered a set for $55 with shipping from china. Got a $50 bill in a late Christmas card.


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