[highwayman]

i just purchased a jet jdm-18 milling machine and i would like to convert it over to cnc. i know that an old bridgport would have bean cheaper better bigger bang for the buck but they apear to be for sale strictly east of the mississippi as the saying goes and im in oregon and have a hard time buying something i cant see touch look at kick shake or pry on to see if it breaks. and ive had good luck with jet stuff if i break it they fix it no matter how much ive welded on it as long as i didnt cause the problem directly. also new is nice cause bearings are in better shape(i am hoping this is an acurate thought process) and it fits in my garage a little better and is more than large enough to start my bussiness with till icome up with something larger to make.

that being said i would like to convert it over to ball screws first to get the slop out of x and y(not sure how to do it on the z axis im hoping someone here will be a little more ingenious than me on that thought) first and keep it manual for now untill i learn a little more about the conversion proccess and i dont have any cad or cnc experience so its all going to be a crash course for me.

P.S if someone could recomend a good cad and cnc related software for us ignorant typ folk it would be nice as i said before i have no experience so something easy to learn would be a good start. thank you all for yor help

[Torsten]

I am converting a Jet Jmd18 and it is a good machine.
Amazing improvement since I upgraded to Ballscrews.
If you have any questions just ask.
What are you planning on machining with yours?

Good Luck

[ViperTX]

Torsten, rolled or ground ballscrews? Sources? I'm debating CNCing my Jet JMD18....

[Torsten]

Torsten, rolled or ground ballscrews? Sources? I'm debating CNCing my Jet JMD18....

Rolled Ballscrews 5/8 nom. dia. from http://www.mcmaster.com/
about the same price as the other mfg's.
They are Thomson screws and nuts.
Made my own Preloaded Antibacklash Nut using two standard ones.
You can calibrate your controller software to account for any
posssible deviation for acuracy.
The accuracy on the parts I have done excedes my ability to
messure but I guess somewhere +-.001 inch.
The ability to climb cut is just amasing, it has exceeded my
expectations of the abilitys of this machine.
Good Luck

[highwayman]

thanks for you guys fast reply. im glad that the jmd 18 is a good machine that means i didnt screw up getting it what did your ball screw conversion cost you?

[Torsten]

I spend about $200.- on the Ballscrews and Nuts.
The Endmaching of the screws was
matched to the drive I designed for it.
It uses Angular thrust bearings for support.
There was a lot of time spend redesigning the
machine in CAD before I even started with
the drives.
This allowed me to ensure a interference fit
between all parts and a practical layout that
works well.
My retrofit maintains the manual use of the machine
on all Axes.

[jcook40]

I wish to convert my Jet JMD-18 to a simple two axis machine. I will do three axis if someone comes up with an easy modification.

Please keep us all posted on your progress and sources. I need an inexpensive conversion, like all of us do. All help is appreciated.

On machining topics I would be happy to help.

Thanks all