[millbert]

I had every intention of buying an X3 or G0704 or other somesuch square column mill/drill and following someone's recipie (probably Hoss' as his stuff seems to be uber complete and well written). My problem was and still is budget. Like everything else in my life, the minute I plan something out and execute it, fifteen other things that suck away every available cent pop up.

I happened across a deal, my boss had a buddy who passed and left a shop full of tools rusting away in the Florida humidity. Two of these were mill/drills. I ended up with a Jet JMD15 and a Jet JMD16 both for $600. I know the purists here will cringe at the round columns, but for what I need, these will fit the bill just fine.

The previous owner had braced the columns so that they would not turn and wired forward/reverse switches into the power supplies. As I clean them up, I am discovering all sorts of mods that serve some purpose or another. My plan is to convert the 15 to cnc with the primary purpose of engraving and small parts manufacture. I'll leave the 16 manual for now, probably using it to make parts for the 16 as well as parts I have been hogging out for years manually.

I ordered a kit from Automation Technology with motors, drivers, BOB, power supply as well as a box to house it in. A computer buddy hooked me up with a desktop with a Pentium D, WinXP, gaming Nvidia graphics card, and stripped the software package to the basics. He installed Mach3, Lazy Cam and Mill Wizard.

Once I put the box together next week and hopefully make motors spin, then I will start making brackets and sourcing pulleys and belts.

Wish me luck!

[arizonavideo]

One of the guys had a good idea for the round column mills. It was to get a stubby drill bit set for the larger drills. Many holes are not that deep and you wont have to raise the head and loose you location.

Sounds like a good place to spend a few bucks.

I liked my round column for what it was. Save the stock parts and if you have room they make a good manual mill/ drill press. The swing head is sometimes the only way to drill in longer stock easily.

[awerby]

The problem with round-column mills is that they lose position whenever you raise or lower the head. A good trick I've heard of to combat this is to mount a laser pointer on the head, and draw a line on the wall opposite to align to whenever you've changed its position.

[wizard]

Good deal. Honestly you should be able to sell one for a good price to help build out your shop.

As for CNC'ing as long as the parts are small the machines won't do too bad. Sometimes you can plan around the registration problem. If the registration problem becomes an issue I'd suggest selling the other mill also and getting a square column machine. If your CNC work ends up outside the scope of spindle quill travel it just isn't worth the hassle. However a little thought and the use of tool holders that normalize cutter length can go a long ways to making the machine usable.

You don't say what you make regularly, but you might consider making a router / bridge mill if the quill travel on this mill is enough.

[millbert]

Here's a few pics of where I'm at right now...I am still cleaning up the machines, so I absolutely know they are disgusting right now.

The JMD15 and the computer setup that will run Mach3


This JMD16 will stay as is, I still like turning wheels!


Here's the stuff from Automated Technology. I got some figurin' to do!

[millbert]

The problem with round-column mills is that they lose position whenever you raise or lower the head. A good trick I've heard of to combat this is to mount a laser pointer on the head, and draw a line on the wall opposite to align to whenever you've changed its position.

The guy who set these machines up did some sort of track on the side that prevents the head from turning. There is an adjustment on it as well, but I had already planned on a laser. I may also try a DRO on the brace or column that would allow me to raise and lower the head and return to my mean work height. He had used these machines for over 20 years for prototyping work and loved them, so they might work for my needs for now.

[millbert]

Good deal. Honestly you should be able to sell one for a good price to help build out your shop.

As for CNC'ing as long as the parts are small the machines won't do too bad. Sometimes you can plan around the registration problem. If the registration problem becomes an issue I'd suggest selling the other mill also and getting a square column machine. If your CNC work ends up outside the scope of spindle quill travel it just isn't worth the hassle. However a little thought and the use of tool holders that normalize cutter length can go a long ways to making the machine usable.

You don't say what you make regularly, but you might consider making a router / bridge mill if the quill travel on this mill is enough.

The main use for the 15 will be twofold, I want to do some engraving with it on round stock (hence the 4th axis) and small part machining, maybe a little spring turning. The other main use for the 15 will be as a learning curve. I want to know how cnc works from the ground up before I move to my next shop and have to hire a machinist and buy a milling center. I don't want to rely on someone else to do all of it for me. I'm not looking for this to make me an "expert" but I really want to know how it works from ground up before dropping mad cash into something which I am completely ignorant.

I can turn wheels with the best of you guys, but I am not a "machinist." I am a gunsmith that knows how to use a mill and a lathe proficiently for what I do. I am comfortable within my knowledge base, but cnc will be stepping WAY out of my comfy zone. Hopefully I can rely on you folks for a bit of guidance (without being told that the only thing round columns are good for is opening soup cans).

[arizonavideo]

On the quill do you plan on adding a ball screw or power the fine feed screw?

[millbert]

On the quill do you plan on adding a ball screw or power the fine feed screw?

I plan on ball screws for x y &z, but just to get the machine up and running I will use the fine down feed. It is the more simple solution for now, and if I can get the backlash manageable by Mach3, then I may save the money to put ball screws on a square column later. I won't really know where I'm at until I pull the table. I do know that there is a power feed on x and I have the original x screw in a box of miscellaneous parts. Not sure what is in there now. We'll see this weekend when I yank it apart.

That being said, for the quill travel, engraving will likely be +/- 1.5mm deep and parts I'll be making (hammers, spurs, sears, disconnectors, triggers, etc.) will likely be 12mm or under in thickness from flat stock. Most of it I make by hand or manually milled is made from 3/8" thick flat stock now, the thicker items I will most likely turn wheels on as needed.