Newbie, back gear questions

T

Theron751

Registered
Registered
Joined
Aug 31, 2021
Messages
8
Hello all,
I purchased an atlas mill model mf at an auction about a month ago. Serial 004048.
After 3 weeks of reading this forum and downloading specs for a drawbar, back gear wrench and manual I lubed it according to the chart and turned it on. Thankfully it just hums, can barely hear it running. Of course after 34 years of construction I say the same about jet engines!
Anyway I am happy with it but have a couple questions.

The back gear pin on my machine has a set screw holding it in. After making a wrench and fiddling with it for hours I figured that out, loosened the set screw and the pin popped right out.
So questions are1) is set screw normal or PO modification?
2) Is the purpose of back gear to increase spindle speed?
3) is there any way to reverse spindle direction or is that even usefull?

If these have been asked and answered maybe you could point me in the right direction?
Thank you.
 

Attachments

  • 20210906_120024.jpg
    20210906_120024.jpg
    3 MB · Views: 19
  • 20210906_120016.jpg
    20210906_120016.jpg
    3.3 MB · Views: 19
  • 20210828_180323.jpg
    20210828_180323.jpg
    1.3 MB · Views: 19
The set screw on the direct drive pin (back gear pin) is not factory. My guess would be that a PO lost the detent pin and or spring. Removing the direct drive pin without a rag over the hole for the detent and spring to capture the detent pin when you remove the direct drive pin has a tendency for the detent pin to try for LEO,

When engaged, the back gears decrease the spindle RPM by about 6:1.

The only way to reverse the spindle would be to reverse the motor. You would have to work at it to dream up a reason for doing that.
 
Last edited:
Back gears on a machine tool do two things simultaneously: decrease speed and multiply torque
The transmission in your vehicle does the same.
Like a mechanical transformer, you gain in one parameter but lose in the other, by the same ratio
-Mark
 
Note the correction in RED to my previous post on this subject.
 
I don't know how that happened but try it now.
 
Just for clarification, LEO = low earth orbit. LEOs decay over time (due to not being completely out of atmospheric drag), so in a few years your spring will likely return to earth.
 
You must log in or register to reply here.
Back
Top