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Home made Lathe project


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I was thinking perhaps all smart folks on here could help me out with something and I'll get to that in a minute.  But what I've been building lately is a little home made lathe roughly based on
Dave Gingerly's lathe book except I'm not using aluminum castings but rather I decided to make it out of steel.. A couple of mistakes I've made was one I went cheap and instead of using cold rolled steel I used what I had available which was hot rolled stuff and I've had heck getting everything flat.. But I've overcame this problem with a good amount of valve grinding compound and lots of sweat and I've hand lap the bed down to .002   and not in these pictures which are a couple of days old but I've just about finished making both the cross slide and compound slide of the carriage and I'm getting ready to tackle the head stock. Which brings up my question. In Dave's book he uses a piece of cold rolled 5/8's round stock and bores out the bearings and uses bronze bearing inserts and yada yada ect.  On my lathe I doubled the face plate from 1/4 to half inch and that's attached to a 2' long piece of 1/4 x 2x2 tubing to make it very rigid

 

But I'm seriously thinking pillow block bearings mounted on the very thick plate blocks of steel and maybe going up to 3/4 cold rolled round stock and this shaft will be powered by a v cone step pulley riding on it as well. But better than that perhaps I should look around and find a shaft with a Morse tapper insert that way I could use collets I was thinking, And I'm having heck trying to find what I need on ebay or anywhere else for that matter What do you guys think? Any help would be appreciated.... Why make a cheap lathe? Why not better than having absolutely nothing! But yeah it's been a really fun challenging project so far

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9 minutes ago, Michael Cochran said:

What exactly is you're question/problem? I got lost and even after reading it again I still don't know.

It's awfully rambly to make sense from Michael but it's about as organized as the "lathe?" No mention of what kind of lathe it is, what 3/4" shafting is for, etc. If I had to offer an opinion I'd have to point out it's not rigid enough for anything but a bare bones wood lathe and a nice 4" x 12" timber would be a better choice. Bed and no ways and no pic of what needed hand lapping to a .002?

I may be ramblier but I usually make sense.

Sorry Fred: I grew up around several different kinds of lathes and have the Gingery plans. I'm thinking you don't understand what a lathe really needs to be functional. I admit I may not understand what kind of lathe you want to build. If you have some specific questions I'll do my level best to answer them.

Frosty The Lucky.

 

 

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I'm bad about rambling too and I'm usually good at keeping up with others but I didn't manage this time.

I've thought about building a basic lathe myself but haven't gotten around to trying. Maybe one day when I finally have all the part laying there cut drilled labeled etc I might get around to doing it. Truth is it would probably be one of those tool so i rarely ever use.

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The pillow blocks should be fine, but make sure they have a little wiggle room because you will need to indicate everything in as you final assemble it, and you probably know that.  You should be able to get the bearings from any of the big industrial parts houses, or bearing people, like Timken. I would stick to a 4 jaw (6 if you can find one) manual chuck, You could buy the collet spindle sleeve and a draw bar for a small south bend or atlas, or even a entire headstock, but for that price you could almost buy a used south bend.

 

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After reading a couple of times I think I've got it, You are wanting input on the build of the headstock and spindle. For a small lathe such as this plain bearings will sufice if oiled via a capiliary hole. As regards the spindle, what are your intentions re a chuck/faceplate etc? If you fit a simple hand crank to the spindle end you can cut your own MT1 morse taper easily enough.

I would also suggest taking a good long peruse of the lathes.co.uk page, Absolutely packed with good info on all sorts of lathes and see how they were and still are built, including many one off home builds of various quality.

Keep us updated.....i'm looking forward to see how things progress.

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Sorry didn't mean to ramble but I believe this is going to be much more rigid than the original gingerly lathe. His was a single piece of 3"x 1/4 flat stock bolted to an aluminum casting for starters. But this is a piece of 2"x2"x1/4 thick steel tubing instead of the aluminum casting with a 1/2"thick plate welded plated welded and bolted down for the bed. Naturally when you weld something it's gonna gonna warp and distort. So I spent a very long time handlapping the top surface plate flat. Using the granite block and lapping compound to the point where i can no longer slide a .002 feeler gauge in between the bed and the granite and just in case the granite isn't truly flat I've also been using a long level and several pieces of plate glass as a reference as well...and I'll then lay the those on top of the bed and try to squeeze the feeler gauge in between those and the bed and I finally got it pretty good I feel. Took me about a week!

Yes my main question is what should I do about the spindle for this thing.. I thought about using pillow blocks but I don't think they will be very accurate and now I'm thinking about  using tappered thrust bearings instead and mounting those into a solid block of steel probably about 4"inches thick with the V cone step pulley on the rear end of the shaft

I've not decided on the shaft size yet why I was asking you folks.. Gingerly used 5/8th cold rolled round stock but I'm leaning towards going bigger like 3/4 round stock.. I've been looking at mini lathe spindles that already have like a M2 taper cut into them but their shafts are not very long and they attach to a complicated gear drive as well..

As far as only a wood lathe goes. Nope this is going to be a small home made metal lathe with about a 6 inch swing.I guess you could do wood on it.Again sorry  I should of been clear about that I just assumed you would know what I was shooting for by looking at the pictures.Gingerly says his machine can achieve tolerances up to .001  But what mine will do remains to be seen.  But it's mostly for rough shaping stuff anyways things like handles I won't be making gears I don't think lol but I can see making a milling attachment and a steady rest easy enough later on. Maybe even making the Gingerly back gears for it was well later down the line.  As far as chucks goes I think I want to be able to attach 3 jaw chucks or a face plate or a regular jacobs drill chuck on it.  Just trying to research what my options are before I buy anything. Here's a picture of what I have so far

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It depends on the pillow blocks, some are very precise. Thrust bearings are good too, more durable for multi axis pressure. Have you considered a hollow spindle?

Pipe is stronger than solid rod of the same diameter. DOM mechanical tubing is much more accurate and being seamless stronger than structural pipe. A hollow spindle will allow you to turn shafts that are smaller than the spindle ID. You can buy bearings, pullys, sprockets, gears, etc. to fit most any shaft size. While it'd work I wouldn't go with babbit bearings, too much hassle.

There's no rule saying you can only use 2 pillow blocks, 4 will be more than 2x as solid and accurate, you can average out the fudge. There's always a little fudge, call it +- tolerance. I'd certainly go with a larger shaft 3/4" is mighty small but there's going to be a practical upper limit to what you can work to make the thing. Were I doing this I'd be leaning toward 1" ID DOM mechanical tubing. It's ground to dimension seamless tubing built to close tolerances, strong and rigid over a short length, VERY strong and rigid. The bearings, pully's or sprockets are more expensive but stronger and more accurate.

Frosty The Lucky.

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For the spindle, look up "ER collet chuck" on some discount metalworking sites.  They're a bit expensive (especially on the larger sites) but for about $ 120 you get a ground shaft/system to fit collets up to 3/8" dia holding capacity...plus an externally threaded end which could be used for another chuck of some sort.  Enco has em for about $ 120 US (1" dia which is the cheapest version but 3/4 is also available) which is far higher than I remember..but maybe some other source will have a better discounted version.  It'd save some effort in "rolling your own" and might be worth the cost involved to get the collet chuck you need and a precision spindle basically done.  The spindle might be the one part that's worth throwing a bit of money at, even if you'd rather do the tinkering yourself.

They do make larger ER chucks also but I picked the example as the cheapest I could find in a quick search.

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I like the ideal of 1" ID DOM mechanical tubing,Frosty, But this is still just a little lathe and I think I would have problems boring out a hole that big to fit the bearings , And the budget is really tight right now as well. I thought about saving up and buying a headstock from a micro lathe but again I think I can get away with the multiple bearing ideal. For no bigger than what it is I'm leaning to just buying a spindle that has like a M3 taper on it that way I can buy chucks/face plates for it off the shelf. It's just those shafts are not very long and fitting a pulley rather than the drive gears on it might be a little funky lol

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  • 3 weeks later...

Little update,I took Frosty's advice well almost. I went with the DOM tubing and I would of liked to of got something a little bigger than what I got....I started to get it from some metal website but the shipping was ridiculous! So I wound up getting a foot long piece of 1 1/16th DOM pipe with a 1/2 hole 1/4 wall and I had to take it to a friend who has a mini Lathe and we turned it back down to 1" in diameter.. Some used flange bearings was all I could afford  everything from ebay,. But I'm building the head stock....

Now you may wonder why didn't I go with a bigger diameter piece,Well.... The biggest hole in a step pulley that I could find was only 1" inch and that was almost 40 bucks! I also ordered a die to thread the spindle and it's like 1" 8tpi course right hand thread. I saw I can buy blank backing plates that already have this thread and I can screw that on then bolt my chuck to that. But yeah I'll upload current pics later on today..

 

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I was able to take a few photos then my camera messed up today.. So this may be the last update for a while..  On the main drive shaft that goes into the head stock I used a cape chisel to cut a groove for a half moon key that the step pulley rides on. And it was a real pain but I was able to cut threads on this shaft as well......

Nobody offered up any suggestion on the tread size I should cut, so I went with what I had which was NC 8tpi and I should be able to find a backing plate that will thread onto the shaft and the lathe chuck will bolt to it... Not pictured but I've taken a fan motor and have it mounted and I'll probably use a rheostat to control the speed and I'll start working on the lead screw and split nut here before too long.

While I don't expect this thing to hold tight tolerances or anything like that, it's still better than having no lathe at all to turn wood and metal on.......... to be able to take an oversize shaft and turn it down to fit into a bearing like I had to do with the main shaft here would be very useful I feel anyways.

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