504,056 active members
4,461 visitors online
Register for free
Login
Page 1 of 2 12
Results 1 to 12 of 20
  1. #1
    Registered
    Join Date
    Jul 2016
    Posts
    39

    Yet Another RF45 Build

    I have an Industrial Hobbies mill I inherited which has seen next to no use. So after mulling over the the addition of ball screws and doing something bout the spindle bearings (felt rather gritty when turning the spindle by hand - that can't be good) I think I'll replace the lower bearings with angular contacts, and the upper with pair of deep groove bearings. So for replacing the lower bearings I'm looking at sending the spindle assembly out to a machinery repair place and have them do it. Then I'll look into getting the ball screws. I've been looking at HIWIN 2005 C7 ballscrews.

    I figure that I will go the route (hopefully) of:
    DMM Dyn4 750W servos for X, Y, and Z; and a 1.8 kW Dyn4 servo for the spindle. But I'm beginning to think that lesser may be entirely adequate for X and Y, like 400W servos
    I've decided on the Centroid Acorn board. I wanted the Oak but that will absolutely kill the budgeted amount available for the build. So that uses up the available spaces for the axes as far as the Acorn is concerned. I really wanted, down the road, an axis for a vert mounted rotab which could come in pretty damn handy but 4 is all I'm gonna get out of the Acorn. Ah, so be it.

    I have to work out a gas strut doohickey counterbalance for the head. I've taken out all the gears and stuff,l so at least there will be a little weight taken off the head.. That was the noisiest sonuvabetchin mill I ever heard when I turned it on! I can't hardly stand it! My wife asked "What is wrong with that thing??" Lol!

    So I have the one-shot oiler about half way done. Still need to install the fittings. Have milled all the oil grooves in the ways and on the non-gib angled surfaces as well. Putting in HJA-1 metering units for the X, Y, & Z axes with 5/32" tube. And size 0 for each of the ball nuts. I'm thinking about putting an oil passage hole through each gib that will allow oil to pass through to a groove in the gib to lubricate the mating angled face.

    Ridiculously, the chinese only provided one little tiny oil port on each way! You know da kine, has a little ball in the tiny fitting (meager to say the least). And obviously nary an oil groove.
    And incidentally I noticed they never provide a lead-in for tapped holes nor do they deburr or chamfer anything. Well it's all I've got. And getting a Bridgeport into my basement (let alone with 7 ft. basement ceiling!) assuming I could afford one would be a serious problem. The stairs are very steep and make a 90*° turn at the next to last step!

  2. #2
    Junior Member
    Join Date
    Feb 2012
    Posts
    37

    Re: Yet Another RF45 Build

    We want pictures . Keep us informed. My project is on standby. Lack of funds.

    Sent from my SM-N960U using Tapatalk

  3. #3
    Registered
    Join Date
    Jul 2016
    Posts
    39

    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

  4. #4
    Junior Member
    Join Date
    Feb 2012
    Posts
    37

    Re: Yet Another RF45 Build

    750 watts for z axis should do just fine.

    Sent from my SM-N960U using Tapatalk

  5. #5
    Registered
    Join Date
    Jul 2016
    Posts
    39

    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):

    Attached Thumbnails Attached Thumbnails Milling Dovetail Grooves2.jpg  

  6. #6
    Registered
    Join Date
    Jul 2016
    Posts
    39

    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.

  7. #7
    Registered
    Join Date
    May 2008
    Posts
    1159

    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.
    youtube videos of the G0704 under the name arizonavideo99

  8. #8
    Registered
    Join Date
    Jul 2016
    Posts
    39

    Re: Yet Another RF45 Build

    Quote Originally Posted by arizonavideo View Post
    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?
    Attached Thumbnails Attached Thumbnails Milling Saddle.jpg  

  9. #9
    Registered
    Join Date
    Jul 2016
    Posts
    39

    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)




    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!)
    Attached Thumbnails Attached Thumbnails table clamped to mill.jpg  

  10. #10
    Registered
    Join Date
    Jul 2016
    Posts
    39

    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!

  11. #11
    Registered
    Join Date
    Jul 2016
    Posts
    39

    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):



    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.
    Attached Thumbnails Attached Thumbnails 400W Motor Mount.jpg  

  12. #12
    Junior Member
    Join Date
    Sep 2017
    Posts
    80
    Any updates on your build? Did you go with cyp or BMI bearings? A lot of folks have used the cheaper bearings with success and .0002 runout. Curious to know and see final build.

    Quote Originally Posted by Cabbagestack View Post
    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):



    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.

Page 1 of 2 12

Similar Threads

  1. PM45m(rf45 clone) cnc build log with factory 3hp variable speed
    By gt40 in forum Vertical Mill, Lathe Project Log
    Replies: 99
    Last Post: 06-01-2015, 12:43 AM
  2. An Aussie IH Clone Build (Long Travel RF45)
    By Wallerawang in forum Benchtop Machines
    Replies: 91
    Last Post: 08-28-2014, 10:22 AM
  3. CNC Control & VFD for RF45 build questions
    By bigspike in forum Benchtop Machines
    Replies: 13
    Last Post: 06-19-2010, 08:48 AM
  4. DM45 RF45 Build Thread - it begins
    By mattbesquare in forum Benchtop Machines
    Replies: 72
    Last Post: 06-11-2010, 05:26 AM
  5. My New CNC RF45...
    By GMitchell in forum Australia, New Zealand Club House
    Replies: 7
    Last Post: 09-08-2009, 05:02 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •