Lathe Ways and Carriage

[Antman]

To my not so experienced eye it seems that the majority of manual lathes have a similar arrangement for the lathe bed. I think this is called a double prismatic bed where the carriage rides on a prism and a flat surface and the tailstock fits on a second prism and flat surface. What goes on under the bed? Am I right that there are 2 flat surfaces under the bed where the carriage also rides and these ways prevent the carriage from lifting? It seems there is an adjustment to tighten the carriage down onto the bed on the lower ways? How do the lower ways get oil?
Now a big problem: Seems that I have a small piece of swarf under the carriage, so far only a tiny scratch on the upper flat way, but I want to cure this before any more damage. Is there a way of flushing it out without a complete dissassembly of the carriage? It looks like quite a big job to remove the carriage that will involve a lot of taking things apart and reassembling. Should stripping the carriage be a regularly scheduled part of lathe maintainance? I'm quite worried about the situation and feel I must rectify this before I use the lathe again.
Many thanks,
Ant

 

[JaamieG]

As a premise I must say I am a newbee and it really depends on the type and size of lathe you have. I have stripped down my Myford Super7 including the carriage. The Myford has flat bed surfaces which I found very good to use as a reference surface to set tools height, etc.
the carriage rides and is hold also under the bed surfaces.
I found the dismantling and reassembly quite simple and rewarding. It is always interesting to know intimately your lathe so if a problem like yours arise you will know the entity of the problem and how to solve it.

My two pence ;-)
Cheers,
Giacomo

 

[goldstar31]

Basicly, the answer is that there is no 100% method of removing an embedded piece of swarf from a mating surface. If you look at it logically, that is why 'wipers' were fitted to moving parts in the first instance.
When you proceed further, you will find that there are various grades of things that you will encounter. If you have a Tool and Cutter grinder, you find that it will accrue grinding dust and probably a mixture of grease, oil or water- and if left unattended, you will end up with something akin to valve grinding paste- or worse. If you have a piece of swarf( and how do you know that it IS a bit of swarf and not a £5 note or your pet elephant) you should have the lot removed, pick the offending piece out and oil up the whole lot again- using the oilers and adding oil where it misses.

So adopt a regime of regular maintenance

 

[lensman57]

Hi,

I have a Myford Ml7, a Sieg C1, Taig and a Sherline. The Myford as described by the other gentleman is a one piece structure where the ways are integral with the footing. All the others are based a dovetail system for the ways with varying dovetail angles, 55.5 for Sherline, 45 for the Taig and maybe 60 for the Sieg but I am not really sure about the last one. The ways for the Sherline and the Sieg are then screwed to a base wher this serves as foot- support structure, the Taig uses what is known as a floating design where its ways are only bolted to a slab of Aluminium at the head stock and free floating at the tail stock.

Regards,

A.G

 

[rkepler]

In general any way on a machine tool should be protected by some sort of wiper. Usually, if you pull the wipers and the gib(s) for the opposite way you should be able to lift things up and pull out anything that came in sideways - a feeler gage, welding tip cleaner, etc. might be used to try and dislodge it. If it's really in there you might have to pull the part retaining it completely - in the case of a saddle it's usually a fairly simple of removing the compound, disconnecting the taper attachment (if any) and apron and finally removing anything keeping it on the lathe bed. I'd point out that having everything off would be a great time to fit new wipers and discourage new contamination.

 

[Antman]

My pet elephant is in Cy's veggie patch. Looks like I'll be tearing down the carriage. There's only a feedscrew going through the apron. I guess I should be taking pics, the easier to ask for help if I get stuck.
Thanx guys,
Ant

 

[Antman]

Well I took the carriage off without taking the apron apart, just blocked the apron with wood and wedges to keep it in place. Gave everything a good cleaning. And now I get a chance to use a big word. Cut new felt way wipers from felt I got from the local haberdasher. The old ones were not too bad.
Thanx guys,
Ant

 

[rkepler]

Sounds like you went about it right taking the saddle off while supporting the apron. Replacing the wipers at this point is simple preventative maintenance and your lathe will thank you for it with more years of unworn service.

 

[goldstar31]

Probably the only way to determine 100% success is to remove ALL the oil from the bed and saddle and then degrease it and then blue it. You 'll soon know.

Is this heresy or something new? Not a bit of it. That is precisely what is done in all decent machine tool reconditioning.

Of course, you did something similar when you found a tramline of wear---- and started this thread in the first instance.

Whether you wish to adopt or deviate is unknown. That is what I did and did on many occasions.