I intend to begin converting my Rong Fu RF-45 dovetail column mill to a servo driven CNC system. Currently, I am trying to assess available options, possibly a complete kit like the one from Industrial Hobbies, or potentially doing a full custom conversion myself.

Ideally, I want to retain full manual handwheel control of the mill even after the CNC conversion.

Has anyone embarked on this project using this square column mill or its clones? It would be helpful to know what complete kits are available; also which parts suppliers are favorites. Also, does anyone have ideas for a custom conversion they’d like to share?

Jack

http://imageevent.com/tppjr/rf45dovetailmill
Check this out its pretty cool.I've been considering the same thing but havent bought my mill yet.But this guy did an very nice job.

Excellent input; thanks for the pointer http://imageevent.com/tppjr/rf45dovetailmill .. a nice addition to the repertoire.

I'm relatively new to CNC but my understanding is that hand-wheels on a CNC mill (with ball screws) are about as useful as tits on a bull. The pitch of the screw is so large that they are not self-holding. So to use them for positioning is OK but while machining is not a good idea. A pendant is apparently the correct solution for manual control.

Regards
Phil


........Ideally, I want to retain full manual handwheel control of the mill even after the CNC conversion.
Jack

You do have to keep a firm grip on handles.We have an old BP tracer mill that has ball screws and it has gotten away from me a time or two but it feels so smooth when your cranking those handles .So I always kept a little pressure on the gibs.But Jack once you go CNC you won't go back to hand cranking. :cheers:

Jack, I haven't gotten my RF-45 yet, but when I do I want to add 3 axis CNC and still be able to use the power feed and hand wheels as well as the 3 axis DRO. The folks at MicroKinetics.com say their system will do what I want (though I need to get longer ball screws than their standard kit)... but more checking is certainly in order... good luck..
cheers,
ronmac

I intend to begin converting my Rong Fu RF-45 dovetail column mill to a servo driven CNC system. Currently, I am trying to assess available options, possibly a complete kit like the one from Industrial Hobbies, or potentially doing a full custom conversion myself.

Ideally, I want to retain full manual handwheel control of the mill even after the CNC conversion.

Has anyone embarked on this project using this square column mill or its clones? It would be helpful to know what complete kits are available; also which parts suppliers are favorites. Also, does anyone have ideas for a custom conversion they’d like to share?

Jack
I also reached the folks at Industrial Hobbies:
here's their email response.....
-----------------------------------
I'm considering purchasing the Enco 20" square
column Mill/Drill with tilting head, power feed and DRO, model#307-3237 to get
started on prototype building, then upgrade to CNC when the orders come rolling
in...
I wonder...
1. if your 3 axis CNC conversion kit will fit this mill,

Yes it will, our kit will fit any square
column bench mill.

2. and if it's possible to add the turnwheels back so that I can work it
manually as well as CNC? (they seem to be missing in the photo on your webpage)

No, it is not possible to ad them back.

You can always use the mill “manually”
via a keyboard or joystick though. We removed them for the following reasons:

Safety, the rotating hand wheel on a CNC’ed
mill has broken MANY wrists and lower ribs.

Performance, the extra rotating mass of
the hand wheel effects the CNC system.

Usability, after a mill is CNC’ed
turning the hand wheels is pretty hard, with all the drag of the motors and
such.

Your welcome to give us a call and discuss
these options over the phone.

------------------------------------------
I didn't much like these answers... especially the safety issue since you
can easily disengage the hand-wheel with a spring and key-pin so that it isn't
whinging around when not in use...
anyway thought this might be useful info for you....
cheers, ronmac

Jack,
When I originally converted my mill/drill to cnc, I had all the concerns that you express. I wanted it all. However like many of the posts above, I was convinced that I should not worry about the hand wheels etc.
It has now been a couple of years or so since the conversion to ball screws and full cnc and I am happy to say that I don’t miss the hand wheels one bit. Matter of fact they would get in the way. When doing setup or a miscellaneous drill hole, I find jogging or MDI operations to be far better than I could ever do with the hand wheels. Fast jog is much faster than I could ever turn a hand wheel and cuts are smoother as the feed is steady compared to what I could do with a hand wheel.
You indicate you still want the existing power feed, but the cnc hardware will replace that and you still have the same functionality.

When I did mine, (a round column by the way), there was not much in the way of “kits” that I could find so I basically did a lot of reading on the web and looking at a ton of pictures to see how others did it and then sat down with cad and figured it out myself (along with asking a LOT of questions in this forum). This also gave me the satisfaction of saying “I did it”. Additionally, I learned a lot along the way on how everything is put together and how to fix it when (not if) something goes wrong. Would I do it differently today and starting over again? Sure but there isn’t that much that I would change and it was a challenge to machine the parts on the mill itself and then get it assembled, took a lot of planning to be able to machine the parts. IH puts together a good kit and I am not knocking him, but for me this is a hobby and I like to do as much of the design and work myself as I can.

Good luck on your conversion and how about a log (with lots of pictures) on your progress.

Is the Rong Fu column mill-drill the same as the one ENCO sells ?
This one: http://www.use-enco.com/CGI/INSRIT?PMAKA=325-5184

Or is it the same as the one here: http://ajaxcnc.com/DM45.htm ?

They all look so similar in design and manufacture I can't tell them apart - I have the ENCO model which has been retrofitted to a three axis cnc. I run it with the new EMC2 control. I was wondering if anyone who had done a retrofit had run into problems with gib adjustment. I can't seem to take out the slop in my Z axis - the gib tightening nut seems to bottom out before being fully adjusted - I think I am going to block up the head and remove it in order to take a better look. I may have to modify it.

http://static.flickr.com/43/84261413_c90e95624f.jpg
http://static.flickr.com/43/84260292_764048dd54.jpg

well i guess this reply is over a year old.. but i just saw it. i just finished converting a lathemaster (rf45 clone) and i found that lapping the slides makes a huge difference.. your z axis slop comes from the pin in the center.. (behind where your head mounts)if you go to the industrial hobbies site they have a way to fix it.. i did mine a little different than theirs but it's the same concept.. my z is very tight now

Hi martymoe, can you fill us in on how you did your z- different?
i'll be doing mine soon , and am interested, thanks

Den

where can you buy jog wheel like in that pendant on that blog? Thanks...

Does anyone have a service or user manual for this mill. I just ordered it and would like to pick up a few accessories before it comes but I need more technical info beyond what is published on sales sites. (like quill size, lubrication required, ...) Also does anyone have specs for the leadscrews? I see the conversion kits but I can't afford the whole kit from industrial hobbies right now.

Ideally, I want to retain full manual handwheel control of the mill even after the CNC conversion.

Jack

First comment Please remove the handles! Keep the handwheels if you must, but take off the handles. They are DANGEROUS and will damage you [bash you or break bits off you] or get caught in your clothing!

Secondly, if you are going down the ballscrew route with their much lowered friction, beware that in manual machining , there is a very great chance of backfeeding. Backfeeding is where the [I]cutting forces cause the axes to move unintentionally and unexpectedly.
Needless to say, backfeeding is unlikely to improve whatever you were machining!
You will need to clamp all non-moving axes, and remember to unclamp the axes when returning to normal CNC operations.

All in all best not to have handwheels, except for casual [non machining] machine movements.

This backfeeding doesn't / shouldn't happen during normal CNC use because the steppers should hold the axes steady. That is assuming each stepper is powerful enough for its respective axis!