# Spare 80t Gear for 9x20 Lathe



## Artie

Does anyone know what mod the 920 lathe feed gears are? I have an Enco and would like a spare plastic 80t gear. I know Grizzly has a cast replacement gear but I would much prefer the quieter plastic gear. I see Little Machine Shop has a plastic mod 1.5 80t gear intended for the mini lathe that may work if bored from 12mm to 14mm and if the 920 gears are indeed 1.5 mod. 
There is virtually no online information on this subject so any help would be much appreciated. 
Thanks, Artie.


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## dgrev

Can someone please tell me what is the mod 1 and mod 1.5? It is meaningless to me.


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## Asm109

It is a number that relates to the size of the teeth.  If you take the pitch diameter of the gear and divide by the number of teeth you get the module of the gear.  The units are mm/tooth.
That is how the metric system describes tooth size.
The English system uses the reciprocal of this number.  That is called the Diametral pitch or Dp for short.  Units are Teeth/inch(of pitch diameter)


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## Radials

I have no experience with these gears but have noticed them on ebay before.

https://www.ebay.com/itm/80T-1014-P...121887?hash=item2cd3cf091f:g:~u8AAOSwQHFZkmR4


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## dgrev

Asm109. Thanks for the explanation. From what I can see, that still leaves shaft diameter, and thickness of gear to be stated?


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## dgrev

Radials - thanks for the link. He is only listing that one gear, pity, I need a 32T gear for a Taiwanese lathe.


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## marksbug

I think there the same, possibly different bore, I have both enco 9x20 2 years old and a old(20 years) 7x14 speedway/homier the same as the rest of the generic 7x10,7x12,7x14, mini lathes. Im waiting for a gear at the little machine shop thats out of stock so i can build a reverse tumbler for my 9x20.  if you need chucks bangood has great pricing on them. I gut a 5" 4jaw and 6" 3 jaw cheep!! as always tear them apart&deburr&rebuild , lube before using.anything!!!especialy new stuff!!!   are your gears noisy?? mine were horrendous and would just about run me out of the shop...till I fixed them.


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## C-Bag

Oops, sorry, wasn't paying as close attention as I should.


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## marksbug

correct, if set up correctly there quiet. I have no issues with the plastic gear, kinda like the power feed on my mill it has a plastic gear just incase...  the runout on my extreamly noisey gears was about .014". I rebored the gear incerts(with built in key) concentric ,then  bushed them back with  phosper bronze valve guide liner.(.015" wall thickness) all is quiet on the home front now.


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## marksbug

I have also heard of guys 3d printing new gears...wish i had a printer I wood be making all kinds of stuff!!!


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## savarin

9x20's use module 1 gears.
Why not make your own?
Heres how I did mine for the tumbler reverse.
https://www.hobby-machinist.com/threads/tumbler-reverse.10122/#post-126013
I found the original idea on line somewhere but dont have access to my original bookmarks.
This gears is still in use today.


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## marksbug

yup as I read your post, I see you made new keyed bushings to fix the runnout issue,( witch is the gear noise issue on these lathes) I just bored them on center and bushed them. the one on the gear slector shaft was a booger,I didnt pull the gear pin going through the thin gear bushing as I didnt want to eff up somethingand have to waite for replacement ,or have to make one.(witch is always a possiability) so i put the shaft in my smaller lathe and broched off the high offset portion then bushed it . not hard to do.works great.  as for making a gear...good work, but eye wood rather just order a pair of plastic ones....Im in no hurry, as I have lots of weeds to pull before mowing the grass. keep up the great work!!!


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## royesses

Change 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.

Roy


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## C-Bag

savarin said:


> 9x20's use module 1 gears.
> Why not make your own?
> Heres how I did mine for the tumbler reverse.
> https://www.hobby-machinist.com/threads/tumbler-reverse.10122/#post-126013
> I found the original idea on line somewhere but dont have access to my original bookmarks.
> This gears is still in use today.



Savarin I know it's a bit off topic but there was mention of a possible auto cross feed project for the 9x20 in your thread and a search didn't come up with anything. Did you ever do one or run into a link for something like that?


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## savarin

C-Bag said:


> Savarin I know it's a bit off topic but there was mention of a possible auto cross feed project for the 9x20 in your thread and a search didn't come up with anything. Did you ever do one or run into a link for something like that?


Bill Gruby was making one for his lathe and I believe he finished it.
I didnt have that project on the horizon although I do have to make a new lead screw and nut for the cross slide with bearings and extended travel but still too much going on to start this.


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## brino

dgrev said:


> Radials - thanks for the link. He is only listing that one gear, pity, I need a 32T gear for a Taiwanese lathe.



@dgrev, check your "conversations" or "private messages".
-brino


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## LuJon

dgrev said:


> Radials - thanks for the link. He is only listing that one gear, pity, I need a 32T gear for a Taiwanese lathe.



No specs on this aside from the tooth count posted byt  erniepike on Thingiverse. I will fire one off on the printer and see what it comes out at. 

Thing 1540817 on Thingiverse looks like it might be what you are looking for.   ***I tried to post a link to the download but it got blocked by the spam filter. **


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## LuJon

Finished printing... 12.18mm Bore. 4mmx4mm keyway. 7mm thick at edge with a raised hub that is 9mm.

Look up earniepike on thingiverse to download


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## dgrev

I have found a vendor on ebay USA who was selling a bunch of gears. I got his last 32T. Pure luck that it was correct for my lathe. I will be curious to know how the plastic printed gear will stand up to the drive train forces on your lathe? I read somewhere that 3D printers used 
PVC plastic, which is not know for its strength and does break down with age and UV exposure (sunlight).


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## marksbug

I got some gears from the little machine shop for my enco. yes there the same as the small mini lathes, execpt for some of the mini gears are thinner.the ones I got were the same as my enco lathe just in plastic.    if you find somebody with a gear to scan plenty of people are 3d printing gears. or posibly online the 3d file can be found for gears. there is a few places on ebay that have the plastic and some are renforced with fiber for about $13. I ordered 2 gears when I got mine from the little shop ,just incase I needed a spar. they were on back order for a few months but I was in no hurry and there still sitting there waiting for me to build the reverse tumbler......... this is my 2nd lathe...first was a 7x14, then this 9x20....now....I wish I had 2 sizes bigger....go figer.


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## brino

dgrev said:


> I read somewhere that 3D printers used
> PVC plastic, which is not know for its strength and does break down with age and UV exposure (sunlight).



Actually the most popular plastic is PLA (Polylactic Acid: https://en.wikipedia.org/wiki/Polylactic_acid)
Also poular are HIPS (high-impact poly styrene: https://en.wikipedia.org/wiki/High-impact_polystyrene)
and ABS (acrylonitrile butadiene styrene: https://en.wikipedia.org/wiki/Acrylonitrile_butadiene_styrene)

There are even a number of plastic filaments with embedded metal powders (bronze, stainless, copper) and some with fibres making a stronger composite.

Each have their own characteristics.

-brino


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## brino

marksbug said:


> if you find somebody with a gear to scan plenty of people are 3d printing gears. or posibly online the 3d file can be found for gears.



Autodesk Fusion-360 (free for home use) has a built-in spur gear add-in that makes gear design simple.
I posted a little about it here: https://www.hobby-machinist.com/threads/has-any-body-tried-these-threading-gears.75340/post-642147

-brino


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## LuJon

Tubalcain printed some PLA gears for his atlas lathe and there were plenty of reports from others that they worked great for change gears. It took me 28 minutes to print a 32T gear. 

I need to spend some time learning how to draw the keyway in fusion so I can make any gear I want quickly. 

Sent from my SM-N950U using Tapatalk


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## marksbug

I need to talk my brother into buying a 3d printer.....I already have tomany toys..and he would think it was his idea....


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