Thread: Worn lathe bed ways

Hi All,

So following on from acquiring my New Visby lathe I have begun the process of cleaning and assessing its condition. As one would expect the bed ways are worn quite markedly towards the headstock. Now I don't know if the ways were hardened as part of the original manufacturing process but it is evident that this machine has had a hard life. There is significant scoring and a pronounced lip at the apex of the Vee as you can see. I haven't measured the depth of the wear as yet. It looks like the wiper covers might need to be relieved slightly to eliminate any contact with the ways.. they are brass though..

I gather that there is a huge difference between acceptable machine shop tolerances and what your average garage hack like me considers acceptable and I also assume the cost of having the ways reground is significant and unjustifiable for the average home machinist. Now I know that the saddle ways can be repaired using Turcite or other such material, but I'm wondering how worn is worn before the bed vee way is completely unserviceable?

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It comes down to can you make the parts you want to. If the condition of the bed is such that the lathe won't move smoothly or the surface finish of the parts is being undesirably influenced by the bed, then something needs to be done.

Michael

Originally Posted by Flo

Hi All,

So following on from acquiring my New Visby lathe I have begun the process of cleaning and assessing its condition. As one would expect the bed ways are worn quite markedly towards the headstock. Now I don't know if the ways were hardened as part of the original manufacturing process but it is evident that this machine has had a hard life. There is significant scoring and a pronounced lip at the apex of the Vee as you can see. I haven't measured the depth of the wear as yet. It looks like the wiper covers might need to be relieved slightly to eliminate any contact with the ways.. they are brass though..

I gather that there is a huge difference between acceptable machine shop tolerances and what your average garage hack like me considers acceptable and I also assume the cost of having the ways reground is significant and unjustifiable for the average home machinist. Now I know that the saddle ways can be repaired using Turcite or other such material, but I'm wondering how worn is worn before the bed vee way is completely unserviceable?

20190525_191232L.jpg20190525_191212L.jpg

Welcome to the entrance of the rabbit hole. Be warned now, it's very deep and seemingly has no bottom. Before you know it, if you're not careful, you'll have spent 5X the cost of the machine on metrology equipment........

Michael's answer is a good one. If the work meets your standards, it's good enough.

If the ways are soft, rescraping them is possible but very, very time consuming and you'll need a decent straight edge. Then a granite surface plate, then a Biax power scraper, then.........

PDW

It may just be your good photography but unfortunately that looks pretty bad. The hard thing about having a totally rogered lathe as your first machine it's it's harder to know if a stuffed part is operator or machine error.

Can you lever the carriage up off the ways significantly, if the carriage has dropped a long away the leadscrew and feed shaft may bind towards the headstock

Regards Ralph

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What do the wiper covers look like? On my old mid '40's Macson the way wipers are held in brass castings with brass sheet scrapers on top of those that do physically touch the ways (or were intended to as these were worn to death when I first got it).
My way wipers had been ignored for years and were as hard as a brick and imbedded with fine swarf so were effectively grinding pads - definitely pull them off and have a squiz.

Originally Posted by Michael G

It comes down to can you make the parts you want to. If the condition of the bed is such that the lathe won't move smoothly or the surface finish of the parts is being undesirably influenced by the bed, then something needs to be done.

Michael

I currently have the carriage down at the tailstock end of the bed. I am not wanting to move it any more than I absolutely have to at this point. I'm not going to be machining anything for NASA anytime soon so maybe I can cope with the wear. I am only a hobbyist after all..

Originally Posted by PDW

Welcome to the entrance of the rabbit hole. Be warned now, it's very deep and seemingly has no bottom. Before you know it, if you're not careful, you'll have spent 5X the cost of the machine on metrology equipment........

Michael's answer is a good one. If the work meets your standards, it's good enough.

If the ways are soft, rescraping them is possible but very, very time consuming and you'll need a decent straight edge. Then a granite surface plate, then a Biax power scraper, then.........

PDW

Yeah I'm kind of wary of the rabbit hole thing..

I think rescraping these ways is akin to trying to extinguish a bushfire with a water pistol! I''m not discouraged though.. yet..

Originally Posted by caskwarrior

It may just be your good photography but unfortunately that looks pretty bad. The hard thing about having a totally rogered lathe as your first machine it's it's harder to know if a stuffed part is operator or machine error.

Can you lever the carriage up off the ways significantly, if the carriage has dropped a long away the leadscrew and feed shaft may bind towards the headstock

Regards Ralph

Yeah it is pretty bad but I'm not throwing in the towel just yet.. I'm hopeful that there is some more life left in the old girl.. I think any machining error will be operator induced..

I have the carriage stowed up at the tailstock end and I am gun shy about moving it too much and doing further damage.. But maybe I need to in order to assess it .. I can't run the machine yet as I don't have 3 phase power or a VFD big enough to power it.. I have a 3hp VFD and my initial research led me to thinking that the lathe has a 2hp motor, but turns out it has a 10hp motor!

Wow, you need to downsize that motor 10hp is wayyyy big, what swing is that lathe?

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I'd say just clean it up, use it and see how it goes - don't invest a huge amount of time into stripping it down and repainting/restoring when you know its got significant wear.
If it does what you want to do then great, if not then look at your options.

I managed with a very worn 9" Hercus for about 30 years as it did what I needed to do, and I found with patience I could work around most of its issues and get an acceptable result for the parts I was working on.

Steve

Just run a oilstone over the ways to knock any burrs or high spots off, give the ways a good clean and oil, and give the machine a go. Lathe ways will take a fair bit of punishment before they start making really bad parts.

Originally Posted by Ray-s

What do the wiper covers look like? On my old mid '40's Macson the way wipers are held in brass castings with brass sheet scrapers on top of those that do physically touch the ways (or were intended to as these were worn to death when I first got it).
My way wipers had been ignored for years and were as hard as a brick and imbedded with fine swarf so were effectively grinding pads - definitely pull them off and have a squiz.

The wiper covers are cast brass but they don't have any rubber or sheet stock to back up the felt. The felt is in dire need of replacement.

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I can probably help there. Shoot me a PM with your address and I'll send you a piece of felt.

Michael

Originally Posted by caskwarrior

Wow, you need to downsize that motor 10hp is wayyyy big, what swing is that lathe?

Yeah it surprised me too! The motor is about the size of a 9kg LPG bottle.

I think the lathe is classified as 8.5" (216mm) but as this has a gap in the bed it's about 315mm from the chuck centre to the bed. The current 3 jaw chuck that's installed is 315mm diameter.. With a faceplate installed I could potentially turn a piece roughly 600mm in diameter..

Originally Posted by OxxAndBert

I'd say just clean it up, use it and see how it goes - don't invest a huge amount of time into stripping it down and repainting/restoring when you know its got significant wear.
If it does what you want to do then great, if not then look at your options.

I managed with a very worn 9" Hercus for about 30 years as it did what I needed to do, and I found with patience I could work around most of its issues and get an acceptable result for the parts I was working on.

Steve

Wise words Steve.. There's the pragmatic part of me that agrees 100% with what you suggested and there's the other more inquisitive engineer part of me that wants to tear this thing down completely and do the full refurb.. The struggle is real..

I think I'd like to address some obvious issues with it such as the stiff compound slide. I'll start a new thread for that one as I'll need some advice.. It also has an oil leak which I'd like to address..