Building simple affordable DIY lathe questions

[pecamuzicar]

Hi all machinists!

I am musician, not machinist, but I am occupied with electronics and specially with speakers for so long time. So, after some research on the net I got strong decision to build for my speaker shop, smaller (rather shorter than smaller) lathe about 1200mm long I need for machining at least for the beginning some simple tools for soft speaker parts, iron magnet pole pieces ...

Of course I found Gingery lathe project, but his machines looking to me too weak for my purpose. Still there are so many nice ideas to build machine parts almost from nothing that is very appropriate to me because now I am not able to spend hundereds or thousands euros for this.

Also I found some Open source lathe projects with concrete bed constructions. They seems to me are not serious so much, because mainly there are not very clear explanations about building, technical specifications and good examples of their machines, and after some time they found themselves they are wrong ...

Main part about I am worried is lathe bed. For Gingery lathe bed building style I am not sure how I will make bigger and stronger lathe bed with aluminum casting.

If I will build concrete bed I got some ideas, but I am not sure what exactly structure of concrete and dimensions there are need for real affordable lathe bed and his length I mentioned.

Also I found something about using resins like Epoxy Granite, but I dont know even where I can to find it.

On the end I got idea to make lathe bed from some heavy steel profile like "I" or "U". With "I" profile about the size of 100x120mm cross section, I would weld inside of it profile left and right reinforcements about 5-6 times by length, than machining edges of top plate of this profile to get straight and use them like ways.

About how to get strong and affordable lathe bed I thinking also to use combinations of methods I mentioned, but here I need help with experienced machine builders, so all good advices will be appreciated.

Please only write with simple words and without abbreviations because I am newbie in this field.

Best regards

Peter

[RCaffin]

Making a good lathe is much harder than making a mill. MUCH harder.
Possible, but a lot of engineering knowledge and engineering skill are required.

Cheers

[pecamuzicar]

Making a good lathe is much harder than making a mill. MUCH harder.
Possible, but a lot of engineering knowledge and engineering skill are required.

Cheers

Sorry, but such answers I heard already unnumbered times from many machinists through my life. Otherwise I would not put this thread here, and I don't want to fight and involve in such discussions at all - it is possible, or not -. I will do such lathe slowly step by step, better ever than never, so if you have something useful and concrete to say, please do that.

Regards

[Norvil l]

Sorry, but such answers I heard already unnumbered times from many machinists through my life. Otherwise I would not put this thread here, and I don't want to fight and involve in such discussions at all - it is possible, or not -. I will do such lathe slowly step by step, better ever than never, so if you have something useful and concrete to say, please do that.

Regards

You have a choice to make, either follow your own instincts and build it your way, or listen to those machinists.
Posting here will just get you an endless variety of opinions on how a lathe should be built, and all will be different.

[pecamuzicar]

You have a choice to make, either follow your own instincts and build it your way, or listen to those machinists.
Posting here will just get you an endless variety of opinions on how a lathe should be built, and all will be different.

It means building such a simple basic machine can be speech skill, philosophy, or better poetry :-))). When show will begin, I would to play on my guitar something also :-))))))))

I am joking , but really I am ready to listen to all of you.

With respect

[RCaffin]

Sorry, but such answers I heard already unnumbered times from many machinists through my life. Otherwise I would not put this thread here, and I don't want to fight and involve in such discussions at all - it is possible, or not -. I will do such lathe slowly step by step, better ever than never, so if you have something useful and concrete to say, please do that.

Well, let us know how you do it and how well it goes.

Making a straight bed with hardened ways is very hard at home, but you can try using commercial linear bearings - heavy ones, mounted on a heavy steel base. That is similar to making a mill.

Making the headstock requires two sets of good well-aligned bearings. That's not too hard in principle.

But then you have to connect the headstock to the bed and get the axis of the headstock aligned with the bed. That is more difficult, but it can be done. Self-aligning bearings in pillow blocks might allow this.

You will need a lathe to make the main headstock shaft and to mount the chuck onto it. No choice there.

The tailstock can be drilled by the headstock. Not easy, but possible.

The saddle is easier.

Cheers and good luck.

[pecamuzicar]

Thanks very much RCaffin,

Your methods looking to me very elegant, like in some modern CNC style in contrast to mine. My ideas was mainly like in Gingery style lathe, just bigger. I will consider all something and will be here soon.

Cheers

[wizard]

In fact Gingery alluded to the idea that as one builds the tools in the Gingery series he can go back and build a better lathe. It is really a process of starting with nothing and eventually getting to the point of having a machine shop. It. Isn't about putting a fully functional shop together quickly.

All of that being said one could follow the process to build a better lathe right off the bat. The problem is you would have to scale everything up and choose more modern hardware arrangements.

For your interest though I see zero advantage in going this route over simply buying a small Chinese lathe. They are dirt cheap considering what you get and with a bit of tinkering can be turned into surprisingly capable machines. Such a lathe would allow you to rapidly turn out the other special machines you will need.

I suspect that you will find out relatively rapidly that you will need many more tools.

[RCaffin]

For your interest though I see zero advantage in going this route over simply buying a small Chinese lathe. They are dirt cheap considering what you get and with a bit of tinkering can be turned into surprisingly capable machines.

And MUCH stronger than cast aluminium. But perhaps 'making' is part of the fun?

I suspect that you will find out relatively rapidly that you will need many more tools.

Sigh :-) How veeerrryyy true!

Merry Xmas

[wizard]

And MUCH stronger than cast aluminium. But perhaps 'making' is part of the fun?

You will get no argument there, making is where all the fun is. I was under the impression that was why most of us are on this forum, that is because we find it fun to make things.

As to strength I think you statement about Aluminum is misleading. It isn't perfect and it is soft but it is also similarly strong to cast iron. Cast iron though has many qualities beyond strength that make it ideal for machine tool making.

In this guys case though if he pursues making a lathe I might suggest neither and the use of steel instead. You would still have to follow the gingery methodology to get a reasonable accurate lathe but you would have the potential for a much quicker build, and potentially a stronger lathe. It would be an ugly lathe if done all by hand but functional none the less.

Sigh :-) How veeerrryyy true!

Yeah, tools are a never ending process of saving, searching and buying. My capacity to buy has significantly limited my ability to expand my shop. That is one reason why I don't have objections to somebody building their own tools. Sometimes it is the economical approach, especially if it is an auxiliary tool.

Still in this case I'd expect that buying something would be the wiser move. Even a used machine, that requires extensive repairs, would be a better move than building your own lathe in this situation. Mainly because as mentioned he will quickly find the need for far more tools. A lathe in this case would jump start his ability to start building those speakers.

Merry Xmas

Yes and a happy new years!

[RCaffin]

As to strength I think you statement about Aluminum is misleading. It isn't perfect and it is soft but it is also similarly strong to cast iron. Cast iron though has many qualities beyond strength that make it ideal for machine tool making.

It's not so much the strength per se but the 'wearing' qualities. As aluminium wears it scuffs and sticks and galls and ... not good. As steel or cast iron wear they liberate graphite powder, which makes for a very good long-wearing surface.

Could one cast aluminium and then add hardened steel ways? Very possible, I would have thought. Ah, but how do you bed the ways into the casting ...? Trying to repeat the Industrial Revolution in 6 months is not easy!

Cheers

[metalworkz]

Hello Peter,
I think all of the responses are relevant to your want to build a lathe. I have made the Gignery metal working machines and am fully aware of their capabilities and shortcomings. Casting aluminum and machining it is within the DIY realm and can be done with hand tools and some small power tools. The Gingery bed is a bit thin in thickness and many people have modified the bed by making it a thicker casting and or alloying it with zinc for example. Many have replaced the aluminum bed casting with steel tube, cast iron I beams and more. As long as you can finish the bed surface flat to accept the CRS flat bar or other rail material and it is built sturdy you should have few problems. You can build the aluminum bed in segments and mount them together to form the longer bed. The original bed casting is fairly long and requires a large flask with a lot of molding sand, so it may be easier to reduce the length and make several pieces that can be bolted together. Then use a piece of CRS for the ways in the full length. If you make it with the Gingery book you will be able to modify the aspects you want (like the length) and still have an excellent guide to follow to continue on with the build to the finish. You may want to substitute different things for some areas of the build, but his plans will take you through all the steps otherwise.
I would be glad to help in any way if I can.