584,841 active members*
4,586 visitors online*
Register for free
Login
IndustryArena Forum > MetalWorking Machines > Benchtop Machines > RF-45 Clone Mill > RF45 (MSC branded) with Ajax retrofit
Page 1 of 4 123
Results 1 to 20 of 74
  1. #1
    Join Date
    Dec 2013
    Posts
    290

    RF45 (MSC branded) with Ajax retrofit

    I got a really good deal on this machine from work, we are getting a Hurco VMX42i for the shop. So we no longer needed this mill, I let my boss know I would like to buy the old machine for my self. Got a really good deal on it, and now its time to clean it up and fix all of the wiring in it.

    From what I can tell it is a RF45, made in Taiwan, and the Ajax kit was purchased December of 2004.

    The wiring is a complete mess. The guy who did the retrofit used extension cord cables for just about everything, including the limit switches. Every wire splice in the box is very sketchy, and I've had to fix a few of them in the past. The rest of the machine seems to have been well done.

    Here are a few pictures







    And here is the wiring nightmare inside the control box....



    The 2 white wires running into this relay are a 2 wire home extension cord, that was for the coolant pump.



    I wonder if the wires under the tape were just twisted together?



    And I guess he didn't like the length of the power strip?




    So the first thing I want to do is find a new enclosure and start over completely with the wiring. Thankfully I still have the original wiring diagrams, and the Ajax board is well labeled.

  2. #2
    Join Date
    Feb 2006
    Posts
    7063
    Should be a nice machine!

    There's absolutely nothing wrong with using extension cord wire for the servo motors, pumps, etc. I did the same thing on my knee mill, and it has worked perfectly for many years. You can buy extension cords for far less money per foot (typically half or less) than plain wire from retail sources. Shielded cables are preferred for switches and encoders, but for the motors, pumps, and other devices, extension cord wire works as good as anything.

    The wire nuts and electrical tape leave a lot to be desired....

    Regards,
    Ray L.

  3. #3
    Join Date
    May 2013
    Posts
    149
    what a dream, all the conversion sorted out and only the rats nest to clean up.
    Wisdom results from foolishness!

  4. #4
    Join Date
    Feb 2011
    Posts
    605
    What's all that stuff on the head?
    PM-45 CNC conversion built/run/sold.

  5. #5
    Join Date
    May 2008
    Posts
    1185
    Every house on earth has 50 or more wire caps in use. The don't look good but work fine if they don't get wet.

    Wire wrapping and tape was OK for the bell company's in fact they had names for many of the proper ways to make a wire wrap. The tape you guy used looks poor.

    I did see some marine shrink tubing that had hot melt on the inside that looks like a good product to keep the water and gunk out.

    Didn't Ajax CNC the quill?

  6. #6
    Join Date
    Dec 2013
    Posts
    290
    Thanks guys,

    On the use of extension cords, the use of them on the limit switches bothers me, why run such bulky wiring with a ground wire that is not needed? And the cheap power cord without a ground for the coolant pump. I would rather see a outlet on the back of the box for the coolant pump. And I can't figure out why one would need to put a splice into a power strip cord?

    As for the wing nuts and twisted wires. I've seen to many problems on equipment with these techniques when using stranded wire. Both of these methods are fine when using solid wire though. Right now I have to leave the cover of the box open, and the plc board along with the pc hanging slightly out of the box in order for the machine to work. Not sure if one of the encoder wires on the back of the pc is getting kinked with the pc pushed back, or one of the wires on the plc has a poor connection.

    And the extra stuff you see on the head are coolant rings for the spindle. Their is also a temp sensor on the lower block running to the plc board. Ajax will turn on a pump for the spindle coolant when it reaches a set temp. I need to look into how that works, and see if the sensor needs to run on type j or k thermostat wiring.

    Going to start drawing up a new box in solidworks tonight.

  7. #7
    Join Date
    Dec 2013
    Posts
    290
    Was going to make a test cut today, and the x axis acted up on me again tonight. Did some trouble shooting on the encoders, and right now it seems like the Ajax CPU board is the culprit. I hooked the y axis encoder wire up to the x axis motor and it read properly. Then swapped the encoder wires for x and y on the CPU board, using the y cable on the x motor and encoder port. And the signal was all over the place yet again. I took the pc inside and pulled the card, everything looks ok on it. Will probably try it one more time tomorrow, but its looking like I will have to contact Ajax on getting the board repaired.

  8. #8
    Join Date
    Feb 2009
    Posts
    6028
    There is a difference between a cheap extention cord and decent SO cord. I agree, the use of wire nuts in an enclosure is a big no, and electrical tape with twisted wire is super sketchy. Should be a nice little mill when your done.

    Sent from my Quantum using Tapatalk

  9. #9
    Join Date
    Jun 2004
    Posts
    6618
    I like to use these type splices when you have to make a quick splice for stranded wire.
    McMaster-Carr

    I prefer soldering and shrink wrap for permanent splices. Add a dab of silicone on the ends of the shrink tube and you have a splice that is coolant proof.

    If you have quite a few splices inside a control cabinet though, din rail mounted junctions are probably the neatest way to do it.

    It all depends on the speed of the job for me. I have been guilty of the twist tape splices in the past, but found they fail easily.
    Lee

  10. #10
    Join Date
    Nov 2009
    Posts
    4415
    Mechanical splices are much better than soldering in an environment with vibration.

  11. #11
    Join Date
    Jun 2004
    Posts
    6618
    I try not to have any splices inside a control cabinet itself. With motors on a machine, sometimes splices cannot be avoided. About the only thing I have gotten a good seal on was the soldered splices with double shrink wrap and sealed. Coolant infiltrated the other methods I tried. I thought I had a good seal on those and they were mechanical joints. The sealing was just poor.

    On a side note, they do sell the large wire nuts with silicone already inside them. I think they are designed to work in wet or underground splice situations.
    Lee

  12. #12
    Join Date
    Feb 2009
    Posts
    6028
    You can also get sealing shrink tube, it has sealant inside and once heat is applied becomes a permanent and sealed joint.

    Sent from my Quantum using Tapatalk

  13. #13
    Join Date
    Dec 2013
    Posts
    290
    I completely agree. And on the connections where I need to use ring or spade terminals I will be using bare connectors, and cover them with heat shrink after making a solid connection.

  14. #14
    Join Date
    Dec 2013
    Posts
    290
    So I finally got my board back from Ajax, and after a bit of work its up and running again. While I was waiting for the board to be repaired, I removed the driver board with the intent of drawing up most of the components for a new control box. I managed to cad out the driver board, but never got around to any of the other components. Though I did rewire the limit switches with some smaller wire, and routed a few other things on the machine. So after I got the board back, I put everything back together and found that I had broken a terminal off the 5V relay that goes to the VFD, it was a PCB style relay. So I ordered a proper panel mount relay which I got today.

    The PCB relay is what you see hot glued on top of the driver board in the center, with a red and green wire coming out the left side.


    And I squared up my new vise, its finally ready to make some chips.



    I also broke down and bought these nice ratcheting crimpers, and I now enjoy crimping insulated terminals. The quality of the crimp is amazing. I wish I had bought a set of these years ago.


  15. #15
    Join Date
    Dec 2013
    Posts
    290
    I cut a fairly simple part today, a screen cap for a old air powered parts washer pump. Someone made a crude cover plate for it at some point, a little detail that bothered me ever since I got the parts washer. I first drew this up in Solidworks shortly after getting the machine working. I printed out a 1:1 drawing before cutting it on the mill, and it looked right. One of the holes was off about 0.100", the holes are not symmetrical on the pump housing, or even centered around the shaft. It took me another week before I decided to try it again, and it was still off. I finally got it right today.

    Here is the new part next to the old plate.


    Flashing on the backside


    And here it is on the pump.


    I havent had much time to draw parts up to cut, and I have still been buying tooling and measuring tools. I need to sit down and figure how many more tool holders I need to buy, so I am not constantly having to change tool height offsets.

  16. #16
    Join Date
    Jan 2005
    Posts
    1943
    Congratulations. Nice to have it working I bet. Even though your control cabinet is kind of a mess, it works. Mine is kind of a mess too, but everything does what it is supposed to. I just wish I could even use mine right now. Making a new box and straightening out the ugly wiring is way down the to do list since starting a new house. Good luck.

  17. #17
    Join Date
    May 2013
    Posts
    149
    So jealous, got all my parts, cad drawings, ready to go, I need to get a move on.
    Wisdom results from foolishness!

  18. #18
    Join Date
    Dec 2013
    Posts
    290

    Re: RF45 (MSC branded) with Ajax retrofit

    So I have been cutting a few small parts here and there, figuring out what tooling I want/need, and learning more about whats inside this machine.

    I have 0.0028" backlash on the Y axis. I pulled the ball screw assembly out this weekend and cleaned everything up. Then I repacked the taper bearings and made sure they were set properly. The backlash seems to be coming from the ball nut. I am considering reballing the nut, I called one place that rebuilds them and was quoted $400-500. It has 38mm ball screws, fairly big screws.

    I considered going with a smaller ball screw, but the ways are very tight. I was not able to move the table at all with the ball screw removed. And from what I can tell, the only adjustment on these ways would be to shim them? I have not been able to find any information on this style of linear bearing.




  19. #19
    Join Date
    Feb 2006
    Posts
    7063

    Re: RF45 (MSC branded) with Ajax retrofit

    If you can't move the table with the ballscrew removed, THAT is your problem! ANY machine will have backlash with that much friction. With the screw detached, it should move almost effortlessly.

    Regards,
    Ray L.

  20. #20
    Join Date
    May 2008
    Posts
    1185

    Re: RF45 (MSC branded) with Ajax retrofit

    Well you should be able to move it with a good hard push. If it is that tight you will get stick slip and that is never good.

    Clean and adjust the ways. I can't see them but there must be a way to do it.

    Pull the Y motor and turn the screw by hand. If you have no resistance when you turn the screw for almost any rotation then that is the screw nut or end bearing slop or ball mount.

    You can pull the ball screw and re pack the balls for less than $50 but you need to know the exact size of the current balls. It is fairly easy to do the packing part but you really want to know that it is the nut first.

    Bal-tecâ„¢, Manufacturer of Precision Balls, Ball Bars, and Kinematic Components has all the balls and can measure what you have. You will only need to go .0003" or so larger unless it is really loose which means it might be trashed.
    youtube videos of the G0704 under the name arizonavideo99

Page 1 of 4 123

Similar Threads

  1. MY Bridgeport Boss 5 & AJAX retrofit
    By will_b in forum Centroid CNC Control Products
    Replies: 19
    Last Post: 09-10-2012, 11:40 PM
  2. 13x42 CNC Vertical Knee Mill Ajax Control Retrofit
    By nvdave in forum Vertical Mill, Lathe Project Log
    Replies: 4
    Last Post: 05-18-2011, 03:54 AM
  3. Retrofit CNC machine HBM DM45 (RF45, IH mill, Grizzly)
    By OptiBF20 in forum Benchtop Machines
    Replies: 0
    Last Post: 01-30-2009, 02:36 PM
  4. Ajax retrofit Bridgeport V2XT
    By Riverside192 in forum Centroid CNC Control Products
    Replies: 9
    Last Post: 10-25-2007, 01:21 AM
  5. Hurco Kmb-1m retrofit with Ajax system
    By cybeeria in forum Centroid CNC Control Products
    Replies: 6
    Last Post: 08-04-2006, 05:13 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
  •