# Broke My 80 Tooth Plastic Gear



## Johnwright (May 6, 2015)

Ok, I done went and done it.  Got careless, distracted, (read stupid) and broke my Jet (BD 920 n) 9X20 plastic 80 tooth gear.  Who can tell me the best resource for such gears?  I needed a 30 tooth gear and ordered one from LMS.  It worked ok after I bored the I/D to specs and created a key way.  (A good learning experience).  I would like to just purchase a gear without the additional work, (and dealing with Jets prices) but so far no seller lists the dimensions needed to be confident in ordering.  I might also buy some other gears for threading since I don't have them.   Any help out there from satisfied buyers???
John W


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## RJSakowski (May 6, 2015)

Johnwright said:


> Ok, I done went and done it.  Got careless, distracted, (read stupid) and broke my Jet (BD 920 n) 9X20 plastic 80 tooth gear.  Who can tell me the best resource for such gears?  I needed a 30 tooth gear and ordered one from LMS.  It worked ok after I bored the I/D to specs and created a key way.  (A good learning experience).  I would like to just purchase a gear without the additional work, (and dealing with Jets prices) but so far no seller lists the dimensions needed to be confident in ordering.  I might also buy some other gears for threading since I don't have them.   Any help out there from satisfied buyers???
> John W


Is your gear a metric gear?  You will need to know the pressure angle, pitch diameter, and pitch module for a metric gear.  Module can be obtained by measuring the pitch diameter and dividing by the number of teeth.  The pitch diameter will be slightly less than the o.d. of the gear.  Pressure angle is a little harder to determine though.  Misumi and SDP have accurate 2D and  3D CAD models and you can determine the pressure angle by visual comparison.

Misumi USA sells metric gears that are highly configurable, although not cheap. http://us.misumi-ec.com/vona2/detail/110300428430/?KWSearch=spur+gear
Another source that I have used is http://www.sdp-si.com/estore/coverpg/gears.htm  They sell both inch and metric gears.


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## davidh (May 7, 2015)

do you have a JET part number ?


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## tomh (May 7, 2015)

+1 
http://www.sdp-si.com/web/html/products.htm

I bought some gears from them that fit  the G0602 lathe and was happy with quality and price.
owners  of the G0602  and ( I think the 9x19 ) buy gears from them to make the reverse tumbler for them.
As usual you will have to search for the correct gear and  price.  They should have a chart to go by to get the correct mod pitch.
hope this helps
http://www.sdp-si.com/web/html/products.htm

Tomh


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## tomh (May 7, 2015)

Go to grizzly look at the 9x19  manual on  p=48   fig =73   see if the setup it looks like yours.
It is a metal not plastic gear , but I don't know the pitch.   The 80T  plastic gear for the G0602 is 1.5 mod. 
tom


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## Johnwright (May 7, 2015)

Yes, Davidh, from what I can find, the Jet p/n for the plastic 80 tooth is #1014.  Do you know of a site where the dimensions (mod. Etc.) are listed detailing how the gear is configured?  Surely, someone out there has replaced gears on a lathe as popular as the older Jet 9X20 (Bd920n)


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## davidh (May 7, 2015)

john, here's the part.  I'm a Jet Warranty Repair place.  i have no idea how much shipping would be but i'd be happy to order it for you and ship it to you . . . .     and its plastic for a reason, like a fuse, made to break to save something else that would be much more expensive. .
https://parts.jettools.com/Detail.aspx?PartID=1014


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