CNC daydreaming

[rabler]

I'm daydreaming of building a small CNC mill some day. And probably a plasma cutter too, although I could see myself buying one of those, possibly even used. But the CNC mill is likely first.

This would be at least a year down the road before actually doing. I've got a new shop that's schedule to get framed up in January, and it'll keep me busy for quite a few months (and keep my budget slim) as I'll need to finish it out with insulation, electric, etc. So in part I'm just killing time daydreaming until they start building the shop.

I'm inclined toward starting with something like a PM-940V (that's my current thought), hardened ways, get the Arizona Video ball screws and servo motors, then build it up myself from there. I've read a few threads discussing that. I'm fairly comfortable with messing with electronics. I will probably go with linuxcnc. I'm an old Unix/linux hack going back to the early 80's. I have looked at Centroid Acorn too. I'm still kicking around options so none of this is set in stone. I've looked at Tormach, and while the DIY aproach isn't all that much cheaper, I'm just more inclined to do it myself.

I don't currently use any CAD environment for my hobby work. There was a time in my professional career many years ago where I was heavy into AutoCad, hell I've even done a bit of VLSI layout. But the pendulum swing on retirement was to get away from working in front of a monitor.

Right now one of my biggest challenges is internet bandwidth. I'm using HughesNet satellite service. This means YouTube, while a good resource, is pretty much out of the questions (except if I have insomnia, 2am - 8am doesn't count against the usual quota). It also hampers using any internet CAD tools, like Fusion360. I have a deposit in with Starlink, so hopefully that situation improves some in the very near future.

So what are some good learning resources for doing a CNC mill conversion? What advice do those of you with hands on experience doing this wish you would have heard before starting?

 

[Ulma Doctor]

i too, am seriously considering the jump to CNC- or at least jumping into the unknown as far as learning about programming.
i have seen a few videos and i have a basic grasp of what is happening while the program is carried out
3D printing has already happened on my end,
i imagine reductive g-code may be generated by similar programs to the additive slicer g-code

i'm looking at GRBL control cnc mini routers as a starting point , but i'm not sure if the really cheap ones are a waste of time or to get a more advanced starting unit

 

[Karl_T]

I have refit a half dozen mills and lathes over the years...

IF you have the room, by far the best deal is a dead CNC mill. The iron is nearly always just fine or only needing minor work. Should be able to find one for far less than you would spend any other way. For example, my son has a beautiful Tree knee mill with servos - $2K. You need to kick the weeds but several of these dead CNC mills are around.

 

[ArmyDoc]

Wow. The similarities between you and me are scarily similar. Are you sure your not me from some kind of alternate universe?

Good luck with the shop. I started my shop last year. It can be a slow process and life frequently gets in the way, but it's very exciting. What size shop are you building?

What machines do you have now? My understanding is sometimes even if you go with a kit, the parts can nee refinement.

What size machine do you want/need? Travels, particularly z axis can be limiting on smaller machines.

For CAD, I had been using fusion 360, but they've limited it unless you shell out for the whole price.. I'm looking at solid works for maker's ($100) or free advertising now.

Have you looked into starling? Put my $100 deposit down, but God knows when they'll actually deliver... they say it's going out of beta this month.

Good luck and keep us posted!

 

[ArmyDoc]

For CAD, I had been using fusion 360, but they've limited it unless you shell out for the whole price.. I'm looking at solid works for maker's ($100) or free advertising now.

Your post prompted me to quit thinking about it and do something. So, thanks!

I just ordered (well, started the process anyhow) solidworks student edition, which is available to military veterans for $20/year. It's available on a DVD rather than download which is critical for me because of internet access issues. Uploaded my DD214 and they should get back to me in the next two days with a link to place the order/make mayment.

 

[matthewsx]

We've seen your lathe....

I can't imagine anything less than a full size VMC would be suitable in the new shop you're building. Haas, Fadal, Mazak, etc.

I have a small CNC mill/drill project and I suspect that once you buy a new PM machine and get all the pieces to convert it you will be very close to, or exceeding the price of a full blown VMC. Decent used one can be had which need updated controllers. knee (Bridgeport) type often go for even less $$.

@JimDawson has been an awesome resource for folks on here doing retrofits.

Just make sure when you order power for the new shop you get a lot....

John

 

[rabler]

Wow. The similarities between you and me are scarily similar. Are you sure your not me from some kind of alternate universe?

Good luck with the shop. I started my shop last year. It can be a slow process and life frequently gets in the way, but it's very exciting. What size shop are you building?

What machines do you have now? My understanding is sometimes even if you go with a kit, the parts can nee refinement.

What size machine do you want/need? Travels, particularly z axis can be limiting on smaller machines.

For CAD, I had been using fusion 360, but they've limited it unless you shell out for the whole price.. I'm looking at solid works for maker's ($100) or free advertising now.

Have you looked into starling? Put my $100 deposit down, but God knows when they'll actually deliver... they say it's going out of beta this month.

Good luck and keep us posted!

Well, I did live in Georgia for quite a few years.
40x56x12 shop for the machining and fab/welding. The woodworking stuff (quite a bit) will stay in the current 30x30 shop, along with my electrical stuff and my wife's refinishing bench. All the machines I have now are full manual, a 26x50 Monarch lathe, a K&T 3K vertical mill are the big 3phase machines currently over at the garage by the barns, a Grizzly G757Z mill and Monarch CK (12x30) lathe are single phase currently in the woodshop. I have two surface grinders, both of which need to be rebuilt before use.

I think I can still get an academic license to solidworks. If that's the case I will jump on that.

Starling? Do you mean SpaceX's starlink? If so, yes I'm on the waitinglist.

I have a small CNC mill/drill project and I suspect that once you buy a new PM machine and get all the pieces to convert it you will be very close to, or exceeding the price of a full blown VMC. Decent used one can be had which need updated controllers. knee (Bridgeport) type often go for even less $$.

@JimDawson has been an awesome resource for folks on here doing retrofits.

Just make sure when you order power for the new shop you get a lot....

I hadn't thought of the updating approach. A retrofit would be something I could certianly do.

As far as power, the house currently has a 200A feed which includes the woodshop. There is a separate 200A feed for the barns which is a major reason the RPC, K&T & big Monarch are over there. The new shop will initially be a 200A feed off the house service disconnet, but I'm setting it up so that it would be relatively easy to put in a 400A service split to 200A for the house and woodshop, and another 200A feed to the metalshop.

 

[rabler]

Here is my thread on building a new shop.

 

[matthewsx]

It has been said on here before, "you can't add iron"

Given the space, and your background I think you'll be well served looking for a used but decent condition industrial machine. I think what happens is a shop will put something into production only to have technology or demand change on them and they'll end up with an "orphan" machine. When you're busy making money it doesn't make sense to retrofit old stuff, just get something else and keep the parts rolling out.

Since you have time on your side do some research, figure out power requirements and what machines are good candidates for a retrofit, and start your search.

For inspiration:

Beauty in The Beast: Webb 5BVK Barn Find/Conversion

New to forum & machining generally. Working on two stroke motors drove my initial interest to learn. Started searching for a Bridgeport... Next thing I knew - I was standing outside a barn, 2 hours from my house, looking at a 4K lb non working CNC Webb knee mill. More about how I got there and...

www.hobby-machinist.com

John

 

[JimDawson]

So what are some good learning resources for doing a CNC mill conversion? What advice do those of you with hands on experience doing this wish you would have heard before starting?

There are some good threads on Hobby Machinist and CNC Zone of machine conversions. Mostly small equipment.

But I'm another vote for starting with a commercial built CNC machine. All of the expensive and hard mechanical work is already done and all you have to do is hang the new controller/motors of your choice on the machine and press go to make parts.

Personally if I only had one mill in the shop it would be a BP or clone knee mill with both manual and CNC capability. These machines pop up on eBay and Craigslist occasionally, normally around mid-80's vintage. Nothing wrong with getting a 35 year old machine if it is in reasonably good mechanical shape. For more serious production work, you need a VMC with auto tool changer. These can be found, with dead controllers, for scrap price or less. I saw one for free the other day. Normally if the old machines are lubricated properly through their life, they just don't wear out. My 35 year old Hardinge CNC lathe runs every day and will hold +/- 0.0002'' all day long.