By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Forum House Ad Zone

engaging back gear om Drummond M type lathe

Bull gear

All Topics | Latest Posts

Search for:  in Thread Title in  
james short12/07/2018 10:47:26
3 forum posts

Hi I have just joined group ? and have purchased a Drummond M type lathe 1948 ,How do I engage back gear.I have read some ware that when altering the Bull gear you have to be careful not to over loosen the nut or it falls into the works ,any suggestions

not done it yet12/07/2018 12:34:03
6736 forum posts
20 photos


You will likely get your answer here, but do join the yahoo group for Drummond lathes - as much as I hate navigating any and all of the yahoo forums! Some good posters over there, other than the ones that frequent this forum as well.

NJH12/07/2018 14:12:23
2314 forum posts
139 photos

Hi James

If you have not yet done so look up - they have information about pretty nearly every lathe made. It may set you on the right course.


David George 112/07/2018 20:22:22
1808 forum posts
503 photos

Hi James I have an M Type and to change to back gear there is a slotted screw on the bull gear just loosen and rotate the bull gear with the button to the end of the slot. Then re tighten the slotted screw. You then rotate the back gear lever to engage the mesh on the gears rotate as you do to help engagement. Do the reverse to take out the back gear but after rotating the bull gear slot tighten the screw and importantly hold the chuck and by hand rotate the pulley to make sure that the spring loaded plunger has located you will hear and know when it is. If you need any further info send me a message and it is worth looking on my album's for info.


Edited By David George 1 on 12/07/2018 20:24:51

Hopper13/07/2018 09:02:39
6201 forum posts
321 photos

Welcome to the forum. There are quite a few of us M-type owners on here. Not sure which nut you are worried about falling into the works? If you mean the slot-headed screw on the front of the bull gear that you slacken to rotate the plate to engage/disengage the bull gear, it only needs to be loosened a quarter of a turn or less to allow the plate to be rotated around to the end of its slot. The screw is then retightened before starting the motor.

The main thing is to MAKE SURE the bull gear is disengaged from the pulley unit before engaging the back gear and starting the motor. When the bull gear is disengaged, but the back has not yet been disengaged, you should be able to turn the chuck or spindle by hand freely without the pulleys and belts moving. Once you can do that, engage teh back gear and start the motor.

Ady113/07/2018 09:11:34
5067 forum posts
734 photos

I use a pair of longnose pliers in my right hand to gently pull on the brass pin then my left hand thumb shoves the knurled screw clockwise while my left hand fingers hold the outer rim of the bullwheel

this pushes the inner plate forwards to wedge the pin out and disengages the bullwheel from the pulley, making the backgear system available

Reverse the procedure to go direct drive again

Edited By Ady1 on 13/07/2018 09:14:39

Adrian Harrison04/01/2019 05:37:20
38 forum posts
11 photos

so the slotted screw needs to be tighten and loosen when engaging and disengaging the bull gear?

Hopper04/01/2019 07:28:53
6201 forum posts
321 photos

Yes. Loosen the slotted screw half a turn or so then rotate the plate around so the face cam action pulls the pin outwards and disengages the bullwheel (gear) from the 3-step pulley. Then tighten the slotted screw again.

The plate you turn should have either a small knurled knob sticking out that you push on with a screwdriver to rotate the plate. Or there will just be a small hole in the plate if the knob has fallen out over the years.

You will see the plate has a slot in it that the screw sticks through. You rotate the plate so the slot moves all the way to one end or the other.

Once the plate has been rotated so the drive pin is pulled out, and slotted screw retightened, you should be able to spin the chuck or spindle without the 3-step pulley rotating if its held by hand. This means the direct drive is disconnected. Then you can swing the back gear into mesh with the two gears - the bullwheel gear and the small gear at the other end of the 3-step pulley.

Once you do that, you should be able to pull on the belts to rotate the 3-step pulley on the spindle and the spindle/chuck will rotate slowly. If it is all locked up, you have not disengaged the drive pin properly, so don't start the motor untill you can turn things over by hand first.

Nicholas Farr04/01/2019 08:06:10
3317 forum posts
1530 photos

Hi, according to the Drummond user manual, **LINK** (pages 4 & 5) there is no need to undo or retighten any screws to disengage/engage the direct drive. My Myford version will disengage/engage just as the manual describes.

Regards Nick.

Ady104/01/2019 08:54:55
5067 forum posts
734 photos

I keep them loose myself, but you've got to watch that none of them come out too far or they start to catch on the main headstock housing

A light finger tightness works for me

Adrian Harrison05/01/2019 04:06:15
38 forum posts
11 photos

ok thanks.. with mine I have never moved any screws but it does work as it should so i will make sure nothing is lose

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Latest Forum Posts
Support Our Partners
Rapid RC
Eccentric July 5 2018
Eccentric Engineering
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest