Thanks: 0
Likes: 0
Needs Pictures: 0
Picture(s) thanks: 0
Results 1 to 7 of 7
Thread: HAFCO HM-45 CNC Mill Conversion
-
21st Aug 2013, 02:41 PM #1New Member
- Join Date
- Aug 2012
- Location
- Perth
- Posts
- 2
HAFCO HM-45 CNC Mill Conversion
Hi Guys,
For anyone that is interested I am 2/3 of the way through a CNC conversion of a HAFCO HM-45 Mill
Have not done the Z Axis yet, but have automated the quill just to get it to work until I do the Z Axis.
The quill automation still has a bit of backlash but am trying to compensate inside MACH 3. Did not find any guides on how to convert this machine so thought I would put this up here to show its doable. I had to mill about 5mm off the bottom of the bed to allow the ballscrew to fit in and move freely.
Used BK17/BF17 bearing blocks, 25mm ballscrews C7, some aluminium 100mmx100mmx3mm box section, 800 oz/in X and Y, 1200 oz/in for Z axis
More photo's of the actual conversion available on request.
DSCN0406.jpgIMG_3787.jpgIMG_3788.jpgIMG_3789.jpgIMG_3790.jpgIMG_3791.jpg
Video of it working
and
-
22nd Aug 2013, 12:46 AM #2Golden Member
- Join Date
- Aug 2012
- Location
- Australia
- Posts
- 645
Nice work. I am part the way through a conversion of an SM-MD46 (the same machine as yours except for a larger table and slightly more travel). It is quite a lot if work to convert these machines. I have been working on my mounts in CAD. Still a few weeks away from fitting the X axis. I also went for the C7 ball screws but went for the BF and BK20 mounts for my X and Y and 25 for my Z. My mounting is quite different to yours as I have a confined space. I am mountaing the Servos back along the front (X) and side (Y) of the table. I will also hang my Z off the top side of the column.
There are a lot of people that have done conversions if these machines. All the RF45/PM45/Zay7045/MD46 are the same mill with minor variations. Cnczone (forum) has a lot of threads on conversions of these machines including some great ideas on the "other items" such as one shot oiling the dovetails, enclosures, belt drive retrofits and automatic tool changers. One specky conversion is of a PM45 titled cM5k. There are quite a few YouTube videos on it..
-
23rd Aug 2013, 07:48 AM #3
Hi
I have completed a conversion on my hm45 and will be interested in following your conversions.
My is a little different in that I used servo motors and linear scales.
I found that the z axis need a air spring to help with the weight of the head that weighs in at 100kg. Some people use gas shocks if you can find the right ones.
variant22 do you have a thread with your conversion ?
Russellvapourforge.com
-
23rd Aug 2013, 09:40 AM #4Golden Member
- Join Date
- Aug 2012
- Location
- Australia
- Posts
- 645
Russell, I do not have a thread up on the conversion. I will likely post one when I cut the mounts. I tend to post these things after the fact. I have my DRO install here: http://www.woodworkforums.com/f65/md...uested-169053/
I am interested to know how you are using linear scales? Do you mean linear encoders on the servos or linear scales on the table? (I have a set of encoders for my Keeling servos). One of the more interesting issues is how best to pre-load the ball nuts. I am still not 100% on that part. The Z is currently my last priority. I drew my ball screws in such a way that I could mount a set of hand wheels, so when all is mounted I can still manually machine. I also did some crazy stuff with the Z screw so I could manually operate the Z..
I would be interested to hear more about your conversion Russell. Do you have a thread?
PS: Apologies to all reading my last response. The post was littered with typos and I can't seem to edit it. I need to stop posting here from my phone..
-
23rd Aug 2013, 01:08 PM #5
Hi variant22
No did not have a thread but should have thought.
"Do you mean linear encoders on the servos or linear scales on the table?".....I used the linear scales on the table...you know where it is at all times, not guess with encoders or steps on the motor.
"One of the more interesting issues is how best to pre-load the ball nuts"..... I did this by using belleville washers and two stranded ballnuts. Can post some pic if you wish.
"I drew my ball screws in such a way that I could mount a set of hand wheels".....don't bother you will never use them after you have jog around once or twice it just easier.
One thing I made a point of was to keep the maximum travel distance through the conversion. This lead to some unusual shaped bearing housing. Remember the mill is alway just a bit too small for that next job.........
Re the z drive, all the servo motor are direct drive no backlash, so the head had to be near to zero weight for it so work so I used the air spring over the gas struts.
I run linux emc2 on my mill it is free and work very well.
Russell
PS did not see any mistake in you post..... well that says a lot for me..... maybe you should have kept quiet.vapourforge.com
-
25th Aug 2013, 08:50 PM #6Golden Member
- Join Date
- Aug 2012
- Location
- Australia
- Posts
- 645
I have glass scales and thought about this approach. I read that people had trouble stopping the table from "hunting". Apparently bridgeport tried to use linear scales a while back and had a bunch of issues. I would like to give it a try and if you have had success I would like to know if you ran into any problems with the setup?
I am interested to see this as well. I have a general idea on it, but would be good to see what is working for you.
Agreed. I think I will have full and possibly a bit more travel than I currently have. I am going to cut the casting on the Y axis as I am running double ball nuts. The X should not be a problem as it looks like there is no way it will touch the mounts at full travel. I engineered the Z so that it will have the same travel as currently.
-
26th Aug 2013, 09:47 AM #7
The main thing with using scales is there can be no backlash. If you want you can put a encoder on the motor as well to close the loop this make it 100% controlled.
I have put photos of the double ballnuts and belleville washer arrangement for the x and y mount. Do not look at the ball nut where I cut of part off part of the flange, this was me going down the wrong track.
I made my own bearing housings so the I maintained the travels on both x and y. The motor coupling is a solid custom made part. I used 500w scooter motors that cost about $20-30 each ,Had to modify the drive board a bit to get the full power range but the motors barely get above ambient temperature even after hour of running.
Hope these help give you some ideas with your build.vapourforge.com
Similar Threads
-
SOLD: Hafco Mill (X3 Sieg)
By dmgrai in forum METALWORK - Machinery, Equipment, MARKETReplies: 3Last Post: 30th Jul 2013, 02:14 PM -
VFD and 3 phase conversion of my 45 size gear head mill
By simonl in forum METALWORK GENERALReplies: 64Last Post: 22nd Dec 2012, 10:03 AM -
Mill to Drill Conversion - Would you bother?
By Anorak Bob in forum METALWORK GENERALReplies: 3Last Post: 7th Jul 2012, 01:50 AM -
Belt drive conversion for mini mill
By Tiger in forum METALWORK GENERALReplies: 9Last Post: 27th Aug 2009, 09:10 AM