Re: Yet Another RF45 Build
We want pictures . Keep us informed. My project is on standby. Lack of funds.
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Re: Yet Another RF45 Build
Well it's nearly time to send out the spindle quill assembly to the machinery rebuild service. I'm going to need bearings such as Nachi 7207CYP4 Abec-7.
Then I'll need to start working on the the gas cylinder doohickey, which I don't know exactly how it's configured -- n I know I'll need a 5 gal airtank and the gas cylinder. Need more research. Have to weigh head - I already know the 1.8kW spindle servo weighs about 32 lbs and aluminum mounting brackets, pulleys & so forth for it are about 15, but will weigh the spindle quill assembly soon before I send it to the rebuilder. Then it's time to take down the head from the column at which time I will weigh it. Much work to do on head;
So I'm trying to get a handle on what size servo l need for the Z axis? I can pretty well guess it need not be larger than 1 kW
Re: Yet Another RF45 Build
750 watts for z axis should do just fine.
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Re: Yet Another RF45 Build
Thanks for the reply. Actually I'm going to try to press out the spindle bearings myself, at least. So I'm off to Horror Freight to get a hydraulic press.
In other news we are going to drill & ream the end brackets for the table for 1/4 dowel pins. Going to swing the Bridgeport head round and stand the table upright on the floor I think. Never did anything like that before so in a few days I'll post pictures of that operation. Unusual setup to say the least. Then later will drill and ream for dowel pins in the base for the Y axis as well, which will also be an unusual setup on the Bridgeport. As you all know the asians used taper pins (and some weren't even perpendicular !!) so the idea is to get rid of them and replace with proper dowel pins. I may or may not do that on the top of the head ... don't know yet.
*side note: well my local Harbor Freight couldn't accept any credit cards; their machine was broken so I couldn't buy the 20 Ton Press. Didn't have my 20% Off coupon with me anyway so... so-much-the-better.
well here's a photo milling the grooves in the non-gib angled faces of the dovetails (the oil circuit of the adjacent flat supplies the angled face as well):
https://www.cnczone.com/forums/attac...d=406032&stc=1
Re: Yet Another RF45 Build
So the next problem will be how to accurately locate the X & Y brackets for the ball nuts. I imagine I can install the supports and ball screws and then take measurements from the ball screw to the flat of the dovetail. But that only gives me Z. Looking at the photo above in post #5, getting the Y dimension on the saddle is the problem. How do you accurately locate the ball nut bracket in Y and Z directions?
Then you have the same problem for the other axis on the underside of the saddle in the picture above, for an X dimension, and again Z direction.
Re: Yet Another RF45 Build
To remove the lower spindle bearing race there is two small holes drill in the quill. A small driver will work to push out the race.
On the Y slide if you enlarge the little cutaways they cast in for the X end plates you can get a extra inch of travel.
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Re: Yet Another RF45 Build
Quote:
Originally Posted by
arizonavideo
To remove the lower spindle bearing race there is two small holes drill in the quill. A small driver will work to push out the race.
On the Y slide if you enlarge the little cutaways they cast in for the X end plates you can get a extra inch of travel.
Thanks for that tip on the bearing race!
>> "On the Y slide if you enlarge the little cutaways they cast in for the X end plates you can get a extra inch of travel"
You mean these at each end?
https://www.cnczone.com/forums/attac...d=406414&stc=1
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Re: Yet Another RF45 Build
OK -- so day before Thanksgiving, we have the table now affixed to the Bridgeport table ready to locate the hole features, bolt hole features and capture and record these dimensions as well as the location of acme screw relative to the front side dovetail: (notice we have head swung round and we are indicating it in for three planes)
(note: the table is not touching the 2-4-6 blocks or the dolly - they are there for safety in case there is any slippage while we get the setup done)
https://www.cnczone.com/forums/attac...d=406418&stc=1
So the plan is, like I said, to capture the dimensions of the features relative to front dovetail, go back then and drill & ream for 5/16" standard dowel pins and abandon the taperpin ones. Just going to keep the old bolt holes, they're fine. Then I will carry over the captured acme screw dimension/location and the newly added dowel pin locations to the other end of the table, referencing the same front dovetail. That way when I make up the new end plates that should locate the ball screw parallel to the front dove tail in X,Y and Z. Then it remains to find out how to locate the ball nut bracket on the saddle w/ respect to the ball screw.
Does this sound like a good plan?
(hope all of you had a Happy Thanksgiving!)
Re: Yet Another RF45 Build
Almost forgot to add that I have to mill about 1/4" off the "arches" on the ends of the table as the ball nut will not pass under it when it comes time for assembly and or disassembly -- Like a highway tunnel that's too low for a truck! I'm talking about the "roof" of the table that extends in the first 4" from each end of the table. (hope that make sense)
Secondly this is bit more disjointed then I would like i.e. I would have rather documented the work I did on the saddle first, one shot oiler, oil line fittings metering valves etc. And then moving onto each axis. In a progressive logical manner, like reading a book. But the table and the base (Y axis) has to interject and take precedence & be done rather quickly while I have access to a few strong arm friends and their Jet mills - what with the Holiday, then Christmas too. MUST STRIKE WHILE THE IRON IS HOT !! The work in post #9 will resume on Monday. So it's turning into rather a hodgepodge documenting here on CNCZone. Oh well, at least I'm moving forward !!
--- and thank you ALL for all you input, observations and feedback!
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Re: Yet Another RF45 Build
Thinking more on the X axis brackets, apparently Bridgeport used roll pins, aka spring pins instead of dowel pins. Taiwanese imports apparently use no pins at all, just 4 bolts, such as Jet (see picture above in post #9). So I got to thinking that I will just use four bolts on each end. (see the bracket in the attachment below shown in red )
I found that the servo motor mount assembly with the angular contact bearing supports sold by Automation 4 Less just don't work well for a milling machine application. I was looking for a plug n' play arrangement but I can't find any.
<Sigh> So I will have to make the servo motor mounts myself. (shown in yellow):
https://www.cnczone.com/forums/attac...d=406490&stc=1
Basically just a 3" section of 3x3 A500 square tube with a 3/8" thick cap welded on one end and a 1/2" cap welded on the other suitably bored out and drilled on either end. So I have to make two, one for X, one for Y; and a similar but larger one for Z. These motor mount assemblies will then mount to the X and Y brackets shown in red (Y will be a bit different in outer shape naturally, as will Z). I'm trying to get as compact a direct-drive design as I can, so I think this will work out fairly well.