Re: [CAD_CAM_EDM_DRO] Quandry

Hugh



For the $6000.00 that they charge for the MI4848 I think you could do better
by building your own. See http://www.campbelldesigns.com/ for an idea of what
can be done with 80/20, or some other brand, extruded aluminum. While the router
in the photo is smaller, scaling it up would not be a problem. Order the pieces of
aluminum you need as well as the brackets, bolts etc. and it will show up on your
door in a few days all cut to the exact size, threaded where you need it, and with
all parts to simply bolt the frame together. Add either round shaft or THK type
linear guides and you're almost done. Stepper or servo drives from Gecko and some
motors and screws and you are done. I built one like that, although much smaller
because I got a good deal on THK linear rails and blocks. (I made my router to
fit my linear rails). Very little needs to be done at a machine shop, maybe some
leadscrew support brackets although even they could be bought new.

I think that with all new parts you could build a router of the same size and
quality as the Liberty for less than 1/2 the price. If you scrounge ebay and
other places on the web for the expensive stuff like the linear rails or lead screws
you can save even more. The only problem with that approach is you need
to do as I did and build the router to fit your parts.

I have only seen the Liberty router from the one picture on the website so I
can't judge the quality, but the 80/20 3" X 3" extrusion looks to be as heavy
duty as what they used. I plan on filling the extrusions on mine with some
type of concrete/morter to increase the density of it even more.

If the software is step and direction, then yes, it will work with
standard hardware.

The best part of all is that it's as much fun to build it as it is to use it. Plus
you will know more about that router than a store bought one, and will
know how to make it better when and if you need to.

Bill

Hugh Mahlendorf wrote:

> Group:
> This morning I got some bad news and it has put me in a bit of a
> quandary. As I mentioned in a post to Ballendo, I had ordered a MI4848 CNC
> router from Liberty Enterprises last June. I was promised 8 to 10 weeks
> delivery. After a few delays I was told a tornado ripped through town in
> the last week in June but the shop was spared. A number of trees in the
> area were damaged, however and this included one just outside the Liberty
> shop. The city hired a private contractor to remove the damaged trees and
> -- you guessed it! He dropped the tree on the shop and damaged some of the
> parts for my machine. Specifically, the hardened shafts for the gantry.
> The Owner, Charles told me he was going to redesign the machine for 2001
> anyway and that he would provide me with the newly restyled gantry using
> aluminum extrusions instead of shafts and bearings and that I should expect
> my machine by the first or second week in Sept.
> Rains, I was told, prevented the trucking company from picking up the
> machine until earlier this month but it (and a couple of others) were all
> shipped last week. Hooray! (I thought)
> This morning I called and asked if everything was OK and Charles told me
> he was going to call me. He had just returned from Louisville, KY where he
> was attempting to inspect the remains of all of the machines he had
> shipped. Seems the semi rolled over and the insurance co. won't let him or
> anyone else near them until the finish with their investigation - maybe
> Wednesday.
> I guess this means another 12 to 15 weeks since mine wasn't the only
> machine he was building.
> Now my quandary: Do I wait and hope to see my machine this year? Or do
> I try to find another? Or do I try to build my own from scratch? I have
> done some machine assembly in the past, but I do not have anything but
> woodworking machinery. I can't find another one as inexpensive with the
> same size and features as the Liberty and I am very satisfied with the
> software albeit not having had it tied into a machine. I am perfectly
> satisfied to pay him for the software and hope it is compatible with a
> future purchase of another mfgr.
> I did intend to build my own but NOT YET! But maybe providence is
> forcing my hand.
> So I turn to you, who have already built CNC Machines for guidance. I
> guess what scares me the most is reading all of your posts on the problems
> you have had or are having. Am I ready to take the plunge?
> Sorry for using up so much bandwidth. I guess I needed a place to vent
> my frustration and disappointment but I really do need advise.
>
> Hugh
>
>