EDIT: Picasa Web Album with all the Pictures!
Hello Everyone,
I have had this project in the back of my mind for a few years now. Ive been collecting parts and planing my moves. I think it is finally time to get this project rolling so here I am to document it and hopefully get some advice along the way.
My plan is to build a machine that has a +36" X, +24" Y and ~36" Z. This will be a big machine! I want to be able to do high speed machining on aluminum and reasonable machining on steels and iron.
Now, For the pieces I have acquired.
A few years ago, I met a guy that lives about an hour and a half from me that owns a PCB assembly shop. He was scrapping some machines and that's where I started to get my parts. To make a long store short, I was able to get a full XY gantry out of one machine! It uses 48" THK slides for both axis's and precision ground ball screws! The X slides are LWHS 20 series and the Y is LWHS 15's. This was the heart of the component placement machine and was accurate to +/-0.0002" with repeatablity of +/-0.0001". It is super accurate!! It already had servos with all drives and was ready to go!! So I thought.... more on that later...
Anyways, at least the gantry is solid! Now the base and column was the concern. On the back of this same machine was a fabricated I beam that is the back bone of the machine. It was yelling at me that it was perfect for a column for the Z. Cut it in half, and put the 2 half's together and have a hollow column where the Z screw could fit down inside, protected from everything. As an additional bonus, the rail has some of the biggest THK slides I've ever seen on it! LWHD 35's! each slide block is almost as big as my hand and weighs about 5lbs each! When I looked at the spec sheet for these, they have a dynamic rating of 10Klbs each! Well that will take care of the Z.
The base was the last part in question. I had my eye on another machine he was scrapping and was able to get my hands on the lower half. The base of this machine was built to be strong. All box steel constructional with 6mm wall thickness, with pieces of box for angled cross bracing galore! The icing on the cake is the top of the frame. 1.125" of solid steel with a machine flat finish! The whole thing is about 5' square and 24" tall. The entire unit would sit on 8 leveling fit, which I replaced with 8 leveling casters so I could roll it around.
A few months went by while I was looking for more parts and designing the machine. I was able to pick up a freshly rebuild spindle on Ebay for a Miyano MSV-21. It will take a BT-30 tool holder and came with 2 draw bars and pull stud grippers. One looks a little worn, but the second looks great! I checked it out when I got it, took measurements and created a 3D model then oiled it down and triple wrapped it up in trash bags to keep it safe.
So that brings me to the controls. For 2 years now I have been trying to figure out what to do with the controls. Everything in the machine was working great. It is all Yaskawa CACR-PR 3 phase AC servo packs. The issue, is this stuff is OLD. It can ONLY be powered by 3 phase power, and only clean power. They are not switching supply side like vfd's and newer servo stuff, but instead SCR based rectifier with phase angle monitoring to control bus voltage. This means that without 3 phase power, they do nothing.
I have been looking around for the 2 years for a suitable replacement control system that I can easily power from single phase.
Well, the other day I came across industrial size stepper motors at an affordable price! There is 3 different models, all 4 wire 1.8* per step motors. They are 107, 185 and 247 oz-LB. yes inch pound. The big one is almost 4000 oz-in! At $90, $100, and $120 respectively, they are very affordable. The smallest one is 100V while the other 2 are 130V My plan now is to sell off the rest of my AC servos and controllers to get some cash for the new controls.
What I am planing to use is the Keling KL-11080 which is a 8A adjustable multi-step drive that accepts 110-220 VAC. No power supply required!
I plan to use one of each size stepper on the machine. The small one for the Y, the medium one for the X and the big one for the Z. I will run the drivers with a PMDX-126 Breakout with Smooth Stepper for pulse generation.
The only things left in question would be the spindle motor and control, but I will figure that out later as I go on. If need be, I have a 3.25HP Porter cable router that the base was damaged on, but the rest is fully functional and almost brand new.
Well I think that is enough talking for now. Here are some pictures!
-Adam
Machine Base:
Gantry On Base:
Spindle with Drawbars:
Cutting the Fabricated I-Beam: