11.5 TPI

Just for fun

Just for fun

Tim Young
H-M Lifetime Diamond Member
Joined
Oct 7, 2020
Messages
2,115
I had the desire to cut a 11.5 TPI thread the other day. Found out my 1236T does not cut 11.5 TPI.

I have read through quite a few threads on the subject and have concluded that I either need a 23T or a 46T change gear before my lathe will cut that thread. I have reached out to PM and neither one is available.

I have a friend that has a 3D printer, I haven't asked him yet but I'm thinking if I had a drawing, he could make me one.

So, my question is does anyone have a drawing and/or the file needed for him to make me a gear? Or another solution so I can cut 11.5 TPI.

Tim
 
I had to check, my lathe has the 11.5 setting. Never had a need, yet.

Smart people will be along to help you....
 
Just for fun said:
I have a friend that has a 3D printer, I haven't asked him yet but I'm thinking if I had a drawing, he could make me one.
Click to expand...

Do you have any change gears at all for the machine? If so, measure the outside diameter of one you have (preferably one with an even number of teeth) and report that number and the number of teeth. That will allow us to identify the specification of the gear. You can then download GearDXF and produce an outline of the 23t or 46t gear for 3DP. You will have to measure and draw the centre detail of the gear yourself, but if it is complicated, you can bolt or pin the new gear concentrically to one of your existing gears as long as the one you use is smaller and does not get in the way.
 
Looking at the PM manual and supplemental Thread chart (PM 1236T And 1340GT Thread Chart) it appears your lathe has the same quick change gear box ratios as my Jet 1024. I'm attaching an excel spreadsheet I made, based on the 30t, 32t, 40t and 46t gears I had, that calculates additional pitch combinations that weren't included on my threading placard. What Change Gears do you have? My table also shows you can also achieve 11.5tpi with a 32t/40t combo or 40t/46t combo.

A couple of options:

My change gears have an ID of 0.710 or ~18mm. If your machine uses the same ID, Grizzly has the 32t and 46t in stock (Items# 1117, 1118) for $25.58 & $39.60 respectively. https://www.grizzly.com/products/g9249/parts If the DP is the same you could try and order them from Grizzly.

IMG_7506.JPG
IMG_7508.JPG
IMG_7507.JPG


Then there's Rush Gears: https://www.rushgears.com/tech-tools/part-search/build-custom-gears

You can input your gear requirements and it will output a DXF file that you can use to 3D print your gear.

Hope this helps.
 

Attachments

  • Jet Lathe Threading Table - HM.xlsx
    69.4 KB · Views: 70
The 1236T/1340GT do not cut an 11.5 pitch which is a standard pitch for hoses. Some people have had decent success with 3D printed gears if for occasional use, but there are a number of companies that will make them as a single item.
Two other links for custom gears.

Gear Making | American Machine & Gear Works

www.thegearmaker.com www.thegearmaker.com
 
Funbact said:
The ID of a gear tells you nothing about the spec. of the gear.
Click to expand...

The reference to the ID was so that "Just for Fun" could see if the Grizzly Gears might fit the shaft of his Lathe. No need to even consider ordering the gears if the ID is different. A call to Grizzly could then help determine the DP of the Gears.


As mentioned........
DAT510 said:
If the DP is the same you could try and order them from Grizzly.
Click to expand...
 
I have heard if you single point a 12 TPI thread on the sloppy side, it will fit garden hoses fine since garden hose ends don't have a really long thread. I have no idea if that's true though, haven't needed to try myself yet.
 
Maedler Gears makes metric gears and might have something suitable. You might need to modify it, but since you have a lathe, that won’t be a problem.

maedlernorthamerica.com

Drive-train specialist - Large metric inventory - Maedler North America

Maedler North America offers an extensive range of industrial transmission components for sale. Huge inventory / online store!
maedlernorthamerica.com maedlernorthamerica.com
 
You must log in or register to reply here.
Back
Top