Myford ml7 problem

[Daan SchuitemaParticipant @daanschuitema58136]

Hello,

I have an problem with my metal lathe. It makes a strange noise. Since a week ago.

See the video link for the sound.

https://youtu.be/dXAuQgSknnM

I hope anyone can help me.

Daan

[Daan SchuitemaParticipant @daanschuitema58136]

[RobboParticipant @robbo]

Daan

Sounds like loosely engaged gears to me. Have you checked the changewheels under the cover for their position and engagement. Is the tumbler reverse lever (left hand lever) in the proper position?

 

If they are OK this will at least push you up to the top of the page so some more opinions will appear.

 

 

Edited By Robbo on 27/04/2017 20:58:13

[HopperParticipant @hopper]

Check the driving dog in the back gear is correctly seated and the retaining screw is tight.

[Benny AvelinParticipant @bennyavelin86238]

I agree, it sounds like gears almost in mesh.

[RobboParticipant @robbo]

Thanks Hopper, I forget that one these days, having moved to a Super 7.

[Daan SchuitemaParticipant @daanschuitema58136]

Thanks all for the reactions. The gears are not the problem. I checked this. 

Hopper, I'll see if it's the back gear. any other suggestions? 

Daan

Edited By Daan Schuitema on 28/04/2017 21:25:56

[Daan SchuitemaParticipant @daanschuitema58136]

I have checked it and this is what I have. Is it normal? This kind of 'backlash'?
https://youtu.be/0wBpD6fzfTE

Edited By Daan Schuitema on 28/04/2017 21:41:31

[JohnFParticipant @johnf59703]

Hi, it seems excessive to me particularly with the locking mechanism, I would also point out there is a tooth missing from the Bull wheel.

What I would do is disconnect everything in the drive as far as possible so that only the motor and counter shaft is running then progressively re-connect each section until the noise is apparent again. This will show you where the problem is. Disconnect tumbler reverse, gear train from this, back gear drive, and if possible the countershaft to spindle drive, not easy but you could at least run with the belt slack. Hope this helps !

[HopperParticipant @hopper]

You might want to have a good look at that back gear locking mechanism. And have a look to see where that missing tooth off the bull gear went to. It could be sitting between the gears in the bottom and getting jammed up.

[john lavinParticipant @johnlavin61025]

hi I am doing some restoration on a ml7 , the countershaft bearings needed changing which I managed to do but the new shaft wont go through the bearings which I expected.

I am looking for some ideas on how to ease the bearings I know the correct way is reamers but I dont have any so my options are limited, the only way foward that I can see is to try to borrow an expandable reamer or some emery cloth around a bar in a battery drill. Any ideas would be gratfully recieved. John

[David George 1Participant @davidgeorge1]

Where are you based. If you are near here you could borrow one. Ng17

David

[HopperParticipant @hopper]

 

Before you remove any metal, check the shaft and run a file over each end of it. They tend to get burred up around the flats and keyway where the pulleys and retainer mount. (Or where someone hammered teh shaft to get it out.)

That done, will the shaft go through one bearing but not the other? If so, you have a bent H frame, a common occurrence due to the flimsy Mazak material and the awkward Mickey-Mouse belt adjustment screws that often result in only one getting adjusted and twisting the H frame.

My son and I straightened ours by holding it in the vice and putting a three-foot length of 3/4" bright steel bar through one bearing and bending the H into position until the bar would pass through the second bushing.

Of course, if the bushings have closed up in press fitting you will need a reamer to open them up. No way round it really. You can't (or rather, shouldn't) use a brake cylinder hone or emery tape flapper on a stick in the electric drill to open it out as the abrasive particles might get stuck in the sintered bronze, or the sintered bronze may get smeared.

If you get absolutely stuck, you could possibly take the bushings out, bore them out a couple of thou with a sharp tool, then reinstall them. This would by last ditch desperation though.

 

Edited By Hopper on 08/03/2018 02:05:20

Edited By Hopper on 08/03/2018 02:06:03

[Martin DowingParticipant @martindowing58466]

Posted by john lavin on 07/03/2018 18:45:13:

hi I am doing some restoration on a ml7 , the countershaft bearings needed changing which I managed to do but the new shaft wont go through the bearings which I expected.

I am looking for some ideas on how to ease the bearings I know the correct way is reamers but I dont have any so my options are limited, the only way foward that I can see is to try to borrow an expandable reamer or some emery cloth around a bar in a battery drill. Any ideas would be gratfully recieved. John

Long time ago, when I have bought my ML7 the same trouble cropped in.

First thing you need to do is to make sure that bearing housings are in allignement and it is not unknown for an odd monkey (eg previous owner) to overtension a belt enough to bend a casting.

If any problem here is noticed, it is not that difficult to twist casting back to allignement. Otherwise buy second hand one on ebay, but there is a good chance that you will need to do the same with it. After all there must be a reason to sell.

Once happy with it you may adress oilite bushes. I have used adjustable reamer to this end but there is a plenty of blabber on net that such treatment is detrimental to your bush (pores are clogged etc). IMO you will be fine as long as your reamer is sharp (if in doubt use new blades).

[john lavinParticipant @johnlavin61025]

thanks David George 1

I am in the north west, Merseyside a bit to far but the offer was a nice gesture I used to have a box full of reamers and drills along with a lovely long bed boxford on a industrial cabinet with all the trimmings suds pump lights ect but it all had to go quickly as we were moving house, the other people was pushing to get in.Very sorry to see it all go .

Thanks again John.

[john lavinParticipant @johnlavin61025]

thanks to Hopper and Martin for your replies I will try to get hold of a reamer plus some of your other suggestions I will post back with an update. Thanks again. John

[LynneParticipant @lynne]

John Lavin, I have sent yyou a private message. Regards Lynne

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