# DIY Mill and Lathe



## crackerkorean (Sep 18, 2007)

I am seriously thinking about building a DIY CNC mill and lathe and just wondering what kind of HP I need out of each and RPMs

I know its not as good as even a nice old machine but I do not have the funds nor the room for such large equipment. 

I found several different plans but they all use dremel type drills. I would like to have the ability to do clamps and what not. 

I know nothing about machining metals nor anything else. If this doenst work for working metal I can still use it to cut PCBs for myself.

Thanks for any help.


----------



## Rothrandir (Sep 18, 2007)

If the plans can be posted here, doing so may allow some of us to take a better look at them and offer suggestions.

Personally, I do not see how you would be able to attain any level of precision or rigidity with a made from scratch lathe...particularly one that was made without the use of a "real" mill, lathe, or other real tools.


----------



## David_Web (Sep 19, 2007)

I suggest that you head over to CNCZone.com and READ a LOT.
You will learn about RPM, IPM, FPT and so on.
The building logs of others is a very good place to look. Even if the machine might not be what you want you will still learn a lot. What works and what don't.
And before you start you should understand this quote
"Make chips not dust"
A few threads will explain that.

I am "building" one myself in the meaning that I have gathered enough info to do so without building one from plans but as I am now reading again it is now put on hold.

I know peu made a cnc mill or router. I think he posted here with a link to his build log at cnczone.

And stay away from dremel!!! !!!!!!
they are not made for any tough work and the bearings are crap. They are hand tools that is not meant to take a lot of side force. To quote one
"smoke it not suppose to come out of the spindle"

Good luck!!!
There are many here as well that can help you.


----------



## havand (Sep 19, 2007)

Not recommended, but you could pick up one of those small bidirectional movement tables (not sure of the name) and a decently powerful drill press. Makes for a crude mill.


I looked into buying one of those tabletop all in ones. A machinist helpfully pointed out one in a magazine that as he put it 'was the minimum you can buy to get a real working machine.' With shipping it was something like $1200 + basically all tooling. 1-2hp motors, can't remember.


----------



## crackerkorean (Sep 19, 2007)

http://japoni87.spaces.live.com/
This was built by two guys one of which is a member of anohter forum that I am a member of. He has put me in contact with his partner about any questions that I have.

Granted the one I will be building will be made using alu and much smaller. I know I will not be able to get the precision of a 1000 lathe or mill, especially since I am scavenging parts. 

The particular mill/router (still confused as to the difference) was good to about .005" so about .127mm but I am going for a smaller more rigid design. 

I have signed up at CNCzone so im going to start some reading. 

Wasnt planning on a dremel just not sure what to use instead.


----------



## PEU (Sep 19, 2007)

As suggested cnczone is the place to read, A LOT!

check my router: https://www.candlepowerforums.com/threads/82909&highlight=router

A more detailed log of this build is posted there.

Good Luck!


Pablo


----------



## scott.cr (Sep 19, 2007)

I looked into this at one point, but after adding up the cost of a homebrew I could easily purchase a full compliment of the benchtop tooling from Taig or Sherline.

Machining any material (even plastic) requires tremendous rigidity, ie., a big slab of cast iron! I never fully realized that until trying to drill an axial hole in a piece of pine wood post. By hand, it took me an hour. On a metal lathe it took about five seconds.


----------



## David_Web (Sep 19, 2007)

Yep it's amazing how easy it is to learn how to make triangular holes in sheets of metal. :sigh:
It's also amazing how flexible some drills are.


----------



## crackerkorean (Sep 19, 2007)

Like it was mentioned earlier even if this doenst work for working on flashlights let alone metal or anything else itl work for making PCBs that I do and will use. Its definetly easier in the long run that using chemicals to etch traces or using UV to do it.


----------



## sysadmn (Sep 19, 2007)

Start with CNCZone - there is lots of info. First step is to define what you want to do. If all you are trying to do is mill PCB, even a Dremel can handle that. If you want to remove serious metal to thousandths, you're going to spend more. Also check out the minimill section - they're laughed at, but for <$500, you can get a good start.


----------



## crackerkorean (Sep 19, 2007)

I will be spending much time on CNCzone. A lot of good info there.

I would like to do more that just PCB some metal work but im not expecting 1/1000th of an inch precision out of what ever I build. 

I would like to remove some metal from a mag head but that would be the most of it. I am not sure what is considered serious metal.


----------



## will (Sep 19, 2007)

I took a quick look at this setup ( http://japoni87.spaces.live.com/ ). I don't know what kind of material is machined on this setup, but, I hope it is only wood. There is a tremendous difference in the strength of wood vs metal used in machine tools. I have a few tools that I have purchased over the years. I picked up a used mini-lathe on EBAY and that has served me well. I would agree with some of the suggestions - do some reading, stay away from using a dremel ( I have one and it is good for a lot of things, just not for a motor for any serious machining ) 

Whatever you do - be very careful - I know lots of people who have lost fingers, have scars, or have sustained other injuries.


----------



## David_Web (Sep 19, 2007)

I second that warning!
Steppers at slow speed can generate tremendous amounts of force. Most setups have enough force to bend the entire frame at low speed.


----------



## scott.cr (Sep 19, 2007)

crackerkorean said:


> I would like to do more that just PCB some metal work but im not expecting 1/1000th of an inch precision out of what ever I build.



1/1000th (=.001") is the basic tolerance level that most home builders go for. Centering something on a lathe to .001", and then machining a cylindrical shape so both ends are within .001" of one another is commonplace.

If you think about how a lathe cutter travels, in order to keep a cylinder "perfectly straight," the distance between the cutter and the chuck's axis has to be very precise and consistent. This is probably why South Bend charges like $9,000 to refurbish one of their own lathes!

If you really want to DIY, I say go for it and keep us updated. IMHO, a mill would probably be an easier first project, but with fewer applications for flashlight building. However, it can be used to build a lathe.

You should go on Amazon and look up books on homebrew machine tools written by David Gingery. Most of his workshop plans are for large machinery, but you could probably scale them down to something that will fit your work space.

You should definitely check out Taig and Sherline lathes; they're great learner's tools, plus you can sell them to another CPFer probably for 80% of what you paid for it.


----------



## crackerkorean (Sep 19, 2007)

I did find mention of his books other places and will look into it. 

I would love to buy a Taig or something of the sort but my wife and I are getting ready for me to quit my job and goto shchool full time hence the frugalness of the project.

I planned on making my mill first (bench top) and then build a lathe. I found out that casting metal is not too bad and relitivly cheap so between the mill and being able to cast i should be able to make a useable lathe.

I might look into a regular manual lathe and or mill and work on just converting them to CNC.


----------



## will (Sep 19, 2007)

I learned on all manual machines and I have a fairly good understanding of feeds, speeds and all that. I would suggest you learn basic machine skills manually before you get into CNC. 

Does anyone disagree? 

Also - I don't know where you are located - are there any schools that have adult education courses in machine work?


----------



## crackerkorean (Sep 19, 2007)

I do live close to a tech school but i am in school myself and work 40 hours a week as it is.

I might go ahead and build the fixture and just use it manually to start out with and play. Use something like foam.


----------



## Torque1st (Sep 20, 2007)

Don't try to use a drill press as a mill. There is no drawbar in a drill press to hold the cutter in place. Normal cutting forces will pull the chuck or tool right out of the quill which can be very hazardous.


----------



## sysadmn (Sep 20, 2007)

will said:


> I learned on all manual machines and I have a fairly good understanding of feeds, speeds and all that. I would suggest you learn basic machine skills manually before you get into CNC.
> 
> Does anyone disagree?
> 
> Also - I don't know where you are located - are there any schools that have adult education courses in machine work?



One of the local community colleges put together a coalition of local manufacturers and the machinist's union. If you took and passed the four courses required for an apprenticeship, you got to keep the student's toolkit and got half your tuition refunded - almost $500 in micrometers, calipers, cutting bits, etc, and $1200 in tuition. No strings attached - you didn't have to join the union or even apply for the apprenticeship. Unfortunately, it was two full days a week + project time, or I'd have jumped at it.


----------



## will (Sep 20, 2007)

Torque1st said:


> Don't try to use a drill press as a mill. There is no drawbar in a drill press to hold the cutter in place. Normal cutting forces will pull the chuck or tool right out of the quill which can be very hazardous.



excellent point !!!


----------



## havand (Sep 20, 2007)

Torque1st said:


> Don't try to use a drill press as a mill. There is no drawbar in a drill press to hold the cutter in place. Normal cutting forces will pull the chuck or tool right out of the quill which can be very hazardous.



I agree with you, I was just saying you CAN do it. I've seen it done for milling things like wood.


----------



## Lyndon (Sep 20, 2007)

I've been through this back and forth over the years and finally bought a mini-mill. When I need (as in: I can make money with it) a lathe, I will get one also.

Realistically, you can't build a lathe for less than it would cost to buy one unless you wanted to make a really tiny one with say, a drill chuck to hold your parts. Seig now has a tiny 40lb lathe that Harbor Freight is selling for about $299 I think. It will easily cost you that much in parts to build your own and you'll probably end up with something less accurate. 
Now that everyone is going CNC, a lot of shops are happy to get rid of their old manual machine tools. I've seen a Hardinge lathe sold at a local auction for just over $200.

I'm all in favor of DIY when you can end up with something of higher quality than commercially available, but when it comes to manual machine tools, that just won't happen.


----------



## Torque1st (Sep 20, 2007)

havand said:


> I agree with you, I was just saying you CAN do it. I've seen it done for milling things like wood.


Ummmm... Even with wood it would be hazardous. Tool forces are high even with wood. Especially since spindle speeds are so high with wood. Better to not chance it. Someone got lucky before.


----------



## Rothrandir (Sep 21, 2007)

Manual experience will give you a ground for where to start on a CNC, but I'm really not sure how much.

Prior to using real CNC equipment, All I'd used was my Harbor Freight mini-lathe. Between the crappy toolbits I was using (poorly ground HSS (grinder could barely grind the HSS it was so weak)), low power motor, lack of rigidity, and no real idea of what I was doing at the time, I would have to say that the only thing I learned from it is the proper order in which to do things. What part to turn first, where to chuck, etc. I also got a "feel" for how the metal comes off, but between all of the above mentioned factors, I can't say that it was worth much.

When I first started working at the machine shop, I started out as a button pusher.
After a while just putting in a part and hitting the green button, and watching what it does, and looking through the program, you get a good idea of what speeds and feeds to use for the various materials and sizes. After a few months, the boss thought it was time I started doing setups and programming, and between my experience on my manual lathe, and the numbers I'd been reading while watching the programs the other programmers put in, it wasn't too hard to figure out what to do. Of course, after a time of doing it by myself, I was able to figure out feeds and speeds on my own, and could adjust them accordingly based on how the chips flew, how the chips looked, how long the insert lasted, and so on.

There are always base numbers to look at for any material, you can find them in the machinist handbook. Once you have experience, you can tweak those numbers to make them cut most efficiently.

Feeds and speeds will always vary based on the rigidity of the machine, the type of tool used (carbide, hss, diamond, etc), material, coolant availability, horsepower, etc.
On a manual machine, you're more likely to take deeper cuts, with less feedrate, because you don't want to take any more passes than you need to, and you don't want a shower of hot chips embedding into your face. On your enclosed CNC lathe however, you like to hear the hard rain of chips hitting the inside of the door.
Cutting steel at .018ipr is no big deal when you have a door in between you and the material, but you don't want to do that in the open!


----------



## gadget_lover (Sep 22, 2007)

I'm always the dissenter in this discussion. 

If you really want to build one yourself, you can shortcut the process by buying some parts from commercial products as a starting point. Littlemachineshop.com will sell the spindle from a mini-mill, for instance.

It's quite possible to create your own shop machines. The Gingery books tell you how to make quite a variety of tools. If you look at the Taig lathe you will see that it's possible to make a lathe without a lot of castings.

Daniel


----------

