Good deal on a Lathe

[Chris64]

So I've been looking for a good deal on a lathe for about a year but it really hasn't been in my budget. I've run across a lathe that seems like a good deal. Here's the deal

Clausing 4914 (49 x 14 maybe?) Some things I've seen online idicate that it's 36" x 13". Overall width 6"

I couldn't find anything real definitive online (except one picture here at cnczone).

It includes a 6" 3 jaw chuck. A steady rest. One of those plates to use instead of a chuck. It also includes a bigger 4 jaw chuck that he said fits loose but seems to work ok (yikes).

He said he'd let it go for $350...that seems like a great deal to me. Any advice? He didn't know if it could do metric threading - which is concerning because I would like to be able to do that. Is that something that could be changed?

[snowshovelbmx]

seems like a pretty good deal to me, just as long as it is in good condition. I would go and look over this lathe if possible and just check for wear on the ways, cracked castings and all the usual stuff. I found this page for you but it is of a clausing 4900 series. Maybe this is the same but I am not.

http://www.lathes.co.uk/clausing/page6.html

chris

[Chris64]

Originally Posted by snowshovelbmx seems like a pretty good deal to me, just as long as it is in good condition. I would go and look over this lathe if possible and just check for wear on the ways, cracked castings and all the usual stuff. I found this page for you but it is of a clausing 4900 series. Maybe this is the same but I am not. http://www.lathes.co.uk/clausing/page6.html chris

Thanks for the link...He emailed a pic of it and that's the exact lathe.

From the detail of the pic it doesn't appear to have Metric threading as an option (maybe not a problem in 1968).

I've never owned a lathe before...can anyone help me out on this? It has around 9x6 (54) different thread pitches. Would any of these work as Metric? Do companies make aftermarket gear conversions?

Most of the parts I want it for are for Japanese Motorcycles so Metric is important...but it seems like such a good deal.

[snowshovelbmx]

I could be wrong but I know that with my lathe it comes with an extra gear that I can switch into the gears ont he side of the lathe allowing me to cut metric threads. This may be possible to do with this lathe as well. I would just try to search on the internet as much as possible.. or that link that I gave you has an email link that says he has operation manuals for the lathe. Those might give you the awnser your looking for as well.

chris.

[DSL PWR]

Just CNC it and you can do whatever threads you want

[JROM]

Put a piece of stock in the chuck and put an indicator on it. Then push and pull on the stock and see if the indicator moves. If you can deflect the spindle bearings it's junk don't buy it unless you are willing to rebuild the spindle. Also alot of those older lathes had more then one gear set for different threads. If they don't come with the lathe they may be very hard to find. 350 bucks for a lathe that size is a scrap metal price! BEWARE

[Chris64]

Originally Posted by JROM Put a piece of stock in the chuck and put an indicator on it. Then push and pull on the stock and see if the indicator moves. If you can deflect the spindle bearings it's junk don't buy it unless you are willing to rebuild the spindle. Also alot of those older lathes had more then one gear set for different threads. If they don't come with the lathe they may be very hard to find. 350 bucks for a lathe that size is a scrap metal price! BEWARE

Thanks. I'm hoping this is just one of those great finds. I went sniffing out a lathe and a guy who responded had one he's been sitting on for 20 years...it sounds like it may have been in full production prior to him owning it though.

I contacted Clausing and they're faxing me over the parts list for a Metric conversion. They don't have most of the parts anymore, but at least then I can do some more searching. They will also send me the Blue prints of all the parts for $5 each so I could make them (or get them made).

I have to say that I'm impressed with Clausing (the company) if nothing else.

[Chris64]

Originally Posted by DSL PWR Just CNC it and you can do whatever threads you want

OK, so explain please. I've been meaning to ask how CNC lathes work for threading. For threading, do they engage the feed so that the sync is perfect? Or do they have an encoder on the spindle and somehow keep track of where to be?

I could easily see me converting this to CNC just because I'm a computer geek and I love automation. And I could build cooler stuff!

[Mcgyver]

encoder on the spindle. i don't know the angular resolution required (someone here will) but gather that that, times spindle speed can lead to some high frequency input signals. if you are electronic & computer inclined maybe you'll some great ideas on that? otherwise you need rig a new ratio between headstock and leadscrew, some multiple of 127 (25.4mm/inch *5) is common. ie 100 tooth + 127 tooth = 1.27 (change ration of spindle to leadscrew).

overall, those clausings are nice lathes and you would do well to have one ...BUT... I agree that is a scrap metal price, be very careful. If its complete junk, you'd be better off spending a grand or two and get one good shape, at this price check it carefully. It is decently tooled though (that flat thing instead of chuck is a faceplate). flip side i guess is that how far wrong can you go for $350? Blueridge or one of the tool dealers used to have an online guide to buying used machine tools.

[Chris64]

Well, I hate to say it, but I'm thinking about just picking up one of the typical HF/Grizzly 9/19 Lathes instead. There's a few too many "what ifs" and without metric threading it loses a lot of value for me.

One just popped up for sale by my house and the price is about the same. It's not as good of a deal probably - But I can get rid of it if I don't like it easier...that's for sure.

I better start searching for problems with the other lathe now.

[Mcgyver]

yeah but with the clausing, at least there's the chance its not junk (ducking for cover)

[Geof]

Originally Posted by Chris64 OK, so explain please. I've been meaning to ask how CNC lathes work for threading. For threading, do they engage the feed so that the sync is perfect? Or do they have an encoder on the spindle and somehow keep track of where to be? I could easily see me converting this to CNC just because I'm a computer geek and I love automation. And I could build cooler stuff!

Yes that is it in a nutshell with the added thing that the encoder also includes a single pulse per revolution so the controller knows the spindles angular position. The encoder is several thousand pulse per revolution.

The Z axis is positioned at the starting point and then a threading cycle is started. The controller starts the synchronization with the single pulse and electronically locks the feed motion on the Z axis to the spindle rotation. A little time and distance is often needed for acceleration before the Z is in synchrony.

When a machine has what is called Rigid Tapping the synchronization is so good that the machine can hold a tap in a rigid holder and the feed remains in synchrony throughout the decceleration and acceleration at the bottom of the tapped hole.