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Mine happens to be completely torn apart at the moment...
A. 9 3/4"
B. 4 11/16"
C. 1 5/8"
D. 27 15/16"
E. 4 3/4"
F. 3 1/8"
These are just rough numbers but should do for your planning.
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I am looing for a little help from the G0704 crowd. I have a round column mill drill (build thread) that I have convrted to 2-axis CNC so far. While out of town and working on the design for the Z-axis, I came up with an idea to convert my round column to a square column mill. My idea is to use the column and slide from a G0704 and the spindle from my round column and convert my round column into a hybrid square column. To see if it is feasible I would like to get the dimensions of the column and slide of the G0704. Could one of you guys measure your G0704 and get me the dimensions in the attached picture?
Thanks in advance.
John B.
Mine happens to be completely torn apart at the moment...
A. 9 3/4"
B. 4 11/16"
C. 1 5/8"
D. 27 15/16"
E. 4 3/4"
F. 3 1/8"
These are just rough numbers but should do for your planning.
Thanks. That's just what I need.Originally Posted by rob_b
Having had both the mills in question I can say that the 704 column is not nearly large or strong enough for the RF-31 head.
You could build a new welded column with 20mm linear rails and be OK for about the same money.
Thanks. I wasn't planning on using the whole head. Only the spindle. I don't actually think I will wind up doing it, but if I did, I would make a welded steel box for the head that mounted on the G0704 slide. The spindle would have no independent travel, the only Z axis travel would be in the slide. I would ditch the original motor, and get about a 1-1/2 to 2 hp 3 phase 3750 rpm motor with VFD running through a simple 2 pulley belt drive to the spindle.
Like I said, I probably won't do it. I have been adding it up and $300 for the G0704 parts, then add the steel, motor, and VFD and you quickly get to where it isn't practical for this cheap old machine. I think it is definitely doable, but not economical.
Linear rails was a thought too, but the same economic considerations come into play.
I think I will just go ahead and convert the current spindle travel to CNC and call it a day.
Thanks again
Agree, you can get a 6" x 5" 1/2" wall 36" long piece of square steel tubing for $165.00, then a piece of 2 1/4" x 6" x 12" piece of cast iron for $76.00 at Speedy Metals (cast iron for head mount/slide). Then a good piece of 1" plate to weld to the bottom of the column, rails and blocks and you would have a very nice Z axis.
Plus the GO704 bolts to the back of the base and you would end up with a very short Z axis compaired to doing a steel tube column.
I would either add gussets to the inside if I cut a slot in the front for Z axis ballnut to come through to head mount, or bring the screw down through the head mount and keep the column solid. You would have a very strong, plenty of travel, not to costly Z aixs if you could score some rails & blocks at a good price, plus get the normalizing and maybe even grinding done for the rail mounting flats done at fair prices. It would end up very good if so. You could mill the rail mounting flats and then hand scrape them after normalizing, or maybe even just doing a finish milling after normalizing.
Dave D. the builder of the UMC-10 uses steel tubing for his machines and they are stout. Heck if a triangle back plate was added to the column to tie in with the base it would be stronger than the factory square column ( might be anyway).
Using just the quill is not that bad though, except yuo have the older and smaller setup and I believe they are pretty sloppy in the quill. I am not sure how the inside of the head is made but I have though about boring the quill whole out and then pressing in a engine sleeve and reboring to size to tighten a quill up. The quill may need trueing up before this could even be done but a little lathe work would fix that. If yuo have a buddy in a machine shop that the work would not cost a sleeve can be had for less than a bill.
Anyway just trying to get you thinking before you jump in a buy a column. A steel tube column is what I would atempt, and all though SPeedy Metals doenst have a thinker wall tubing you might find some elsewhere ( 3/4" wall would be stout). Its a lot more work in ways but it would end up being worth it.
Jess
GOD Bless, and prayers for all.
Agreed. The G0704 parts would just be the easy way. Squar tube would be easier in some ways though
Being out of town on business, I have had time to come up with ideas, good and bad. After sleeping on it I think this one may be bad for cost and results. I think it would work with either G0704 parts or square tube, but I would still only have a machine with about 6"x 12" table travel.
Ideally, I would like to get a RF45 clone with 9" stock travel in the y axiswhich I'm guessing coul probably be increased some. Then put a VFD and 2 step pulley belt drive on it eliminating the gearbox. I'm probably better off just waiting to go this route
My father does have a large 2-axis table that he said I could have. Not sure on the travels, but it is about the size if a bridgeport table if I remember right. It is a well built one too. He bought it for a job when he had his shop and used it for the job and then put it away. I may have to get that at some time and build a Z axis for it. Maybe instead of the RF45 clone.??
That just might be a good idea If you have access to a good welder.
The head from the RF-31 is not a bad place to start. You have a good simple spindle and two good pulleys. If you make a head to hold the quill and the pulley support and skip the idler pulley you would be OK with the stock motor until you get a VFD.
When I had the Rf-31 I had a few plans on CNC it but I just got a IH mill instead.
I have two 6" x 1/4 wall x 4' that cost me around $90 each. Some day I will make a mill from scratch just for fun but it wont cost less than a import mill.
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