Myford ML7 Apron rebuild

[SeadogParticipant @seadog54734]

Hi all, I recently picked up a Myford ML7 lathe with considerable backlash on the saddle/apron traverse. I have bought all the bits I need and today pressed out the two oilite bushes for the hand traverse pinion and the rack pinion. I noticed when I did it that one of the bushes was slightly proud (one is about 1.5mm longer than the other) but then completely forgot (senior moment) which gear the longer bush is supposed to support.

I thought that it was on the rack pinion gear, but looking at YouTube videos, some have the longer bush on the hand traverse pinion (i.e. the handwheel gear) but others have it on the rack pinion gear, I can't tell from the drawings so can anyone help here please?

[SeadogParticipant @seadog54734]

[DMRParticipant @dmr]

Seadog,

Bumped you up so you may get an answer. Your wording is not too good and you don't say what your replacement parts are. Logic says the heavier load and most (sideways) wear is on the rack pinion. I am not ML7 but the manual does not show any bushes in the apron and I do recall sloppy handwheels on well-used models. There is some merit to bushing the apron for both shafts if that is the case.

Dennis

[egaParticipant @ega]

I can't answer your specific question but will mention that when I faced the same problem on my S7 I opted to make the new bushes slightly eccentric so as to get the gears to mesh nicely.

[SeadogParticipant @seadog54734]

Posted by DMR on 14/03/2023 18:02:51:

Seadog,

Bumped you up so you may get an answer. Your wording is not too good and you don't say what your replacement parts are. Logic says the heavier load and most (sideways) wear is on the rack pinion. I am not ML7 but the manual does not show any bushes in the apron and I do recall sloppy handwheels on well-used models. There is some merit to bushing the apron for both shafts if that is the case.

Dennis

DMR

The later ML7 did not have bushes but mine, being an earlier model does. See part D17 here: Myford ML7 Apron – The holes in the apron for the bushes are both the same depth, but, as mentioned, the oilite bushes (both original and new supplied) are of different lengths thus one bush will be proud at one end when pressed in to the casting – I do remember that both bushes were flush with the outside of the casting so it is inside the gearbox where the bush will be proud pressing on the washer on the back of the gear. But which one?

Hope I've made it a bit clearer, if you look at the link you should be able to see what I'm on about.

Alan

Edited By Seadog on 14/03/2023 20:21:53

[Martin KyteParticipant @martinkyte99762]

According to the parts list the bushes are the same.

Why don’t you give Myford a ring and ask them.
Regards Martin

[SeadogParticipant @seadog54734]

Posted by Martin Kyte on 14/03/2023 20:58:56:

According to the parts list the bushes are the same.

Why don’t you give Myford a ring and ask them.
Regards Martin

Martin,

The spare bushes come as a pair – only one part number, but the fact that they are of different lengths is not mentioned:Oilite bushes There is approximately 1.5mm difference in length, it's obviously done for a reason but why? If only I hadn't had a brain freeze or whatever when I took the old ones out of the apron I wouldn't have this problem.

I did give Myford a ring but the person I spoke to didn't know. I'm hoping to hear back from them but could be ages or never so I thought I'd try here as I've found this site a mine of information in the past.

Alan

[AJWParticipant @ajw]

Just popped out to take a look at my myford apron which still has original bushes. The bush above/left of the handwheel is above the front surface of the apron by about the amount you mention – but yours you say was flush with the outside?

Alan

[SeadogParticipant @seadog54734]

Posted by AJW on 14/03/2023 22:32:28:

Just popped out to take a look at my myford apron which still has original bushes. The bush above/left of the handwheel is above the front surface of the apron by about the amount you mention – but yours you say was flush with the outside?

 

Alan

Thanks for having a look, I'm as sure as I can be that they were both flush on the outside (doubting myself even more now!) and it would make sense for the two gears to align properly inside the gearbox – if one bush was proud, it would push the gear it was supporting farther into the gearbox and as such not mesh properly with the other gear. The more I think about it I wonder if mine was as yours is and a previous owner pushed the bush farther in to try and push the rack pinion gear more onto the rack to 'help' remove the backlash……if you see what I mean.

I'll have to have a look and see if I can find any pictures of other ML7 aprons. Thanks again.

EDIT: Alan, thanks very much, just had a look at a couple of aprons for sale on eBay and they are as yours, so that's sorted. Cheers!

 

Alan

Edited By Seadog on 15/03/2023 08:29:50

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