Help...lathe auto feed stopped working.

Suzuki4evr

Suzuki4evr

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Hallo guys.

My big Mashstroy (Bulgarian make) 1.5m lathe decided today that today is a good day to stop its power feed from working. It starts feeding,stop,go a bit and so it goes on and on and it does this with the carrige forwards and backwards and the same with the cross slide. Now I have never stripped a saddle before so I am a little out of my depth here. From what I have gathered so far is that the problem seems to be where the hex shaft in the middle below the leadscrew goes through a bushing that I think is an engagement bush of some kind? When I run the machine it sounds a bit rattly in that aria and when I stop the spindle,it feels a bit loose in the bushing. Can someone advise me if I am on the right track if I say thay I think that the bush mentioned,has a hexagonal ID and that it is starting to strip or has already. My fear is,and I think there is no way around this, that I have to strip the carriage and repair what ever is wrong. I must mention that this is a big lathe and this carriage is going to be heavy even when the cross slide,compound and top slide has been removed. Guys.....any any any advise will be welcome. I know most probably nobody here will have this model lathe,but I thik the basics is the same,so if someone has done this before, please advise me on tackling this job.

Thanks everybody.
Michael
 
Papa Charlie said:
Not sure about this lathe, but it could be a key or pin that has sheared and you are seeing it catch and then slip which would account for the start and stop action you are describing.
Click to expand...
Will check that first before stripping. Thanks.
 
A picture of the apron and shafts entering it would be helpful. Most larger lathes have shear taper pins at the gearbox exit and or keys in the carriage/cross feed driveshaft inside the apron.
 
jcp said:
A picture of the apron and shafts entering it would be helpful. Most larger lathes have shear taper pins at the gearbox exit and or keys in the carriage/cross feed driveshaft inside the apron.
Click to expand...
I will take pics tomorrow morning best I can. I would have liked to rather post a video,but I don't think I can.
 
Pretty easy to check really. The carriage/cross feed drive shaft will start and stop rotating randomly if it's a key or a shear pin in the gearbox. If it's a key in the apron the driveshaft will continue to rotate as the apron or cross feed starts and stops randomly.
 
Realize this is not your lathe but maybe it will help illustrate. Item 18 is a roll pin in this case. It is covered by item 17. I found an image here on the forum of your lathe. The pin shown below that we are talking about may be under the collar I have circled in the second image.

Lead Screw.JPG
Lead Screw.JPG
 
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If it's the driveshaft pin it's #18 on shaft 7. Don't think it's the lead screw pin. Papa, is there an exploded view of the apron available?
 
My old Logan had a clutch that got loose one time and behaved that way. It was a simple adjustment.
 
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