Build Thread- Early 1900's Rockford Horiz./Vert. Mill cncpc-retrofit

[GM1G]

Got this old mill from a guy in Pittsburgh
Decided I wanted to try retrofitting a pc to it
so here are some pictures of the crap ive done so far
not expecting it to be a super precision machine
more of a programmable power feed
neighbor gave me his old weight bench and i chopped it up
to make this ridiculous looking counterweight deal for it
also i have not drilled any additional holes in the machine
as it is in pretty good shape for being so old
i wanted it to be able to be taken back to stock configuration

Page Title

[GM1G]

i know im new here
but you guys could at least
tell me how stupid it looks

[Ark1]

The one thing with this form is that it is huge! A lot of people just look for ideas and applications. You have gone far beyond that. Worm gears in the Drive? What kind of Lash do you have? Is it less than .060"?

Although a part of history, it is machines like these that liberated manufacturing and obtain repeatable tollerances. Now not to today's standards but this machine was part of the revolution of manufacturing. Before this we had hand tools like saws and files. Don't laugh a lot of old steam engines were made from castings and fitted with files and hand reemers.

What you have embarked upon is a learning experience. That is admired. This is a starting place and see what you and the old and new can come up with.

How many axis will you be powering, I see three motors on the table. Explain the counter weight, to take load off of the table?

Ark1.

[GM1G]

Originally Posted by Ark1 The one thing with this form is that it is huge! A lot of people just look for ideas and applications. You have gone far beyond that. Worm gears in the Drive? What kind of Lash do you have? Is it less than .060"? Although a part of history, it is machines like these that liberated manufacturing and obtain repeatable tollerances. Now not to today's standards but this machine was part of the revolution of manufacturing. Before this we had hand tools like saws and files. Don't laugh a lot of old steam engines were made from castings and fitted with files and hand reemers. What you have embarked upon is a learning experience. That is admired. This is a starting place and see what you and the old and new can come up with. How many axis will you be powering, I see three motors on the table. Explain the counter weight, to take load off of the table? Ark1.

hello
and thank you for your reply
i figured noone gave a crap or everyone thought it was dumb
yes this is a learning experience - i have no formal machining experience
so im just making it up as i go along

the table and knee along with the motors and mounts are pretty heavy
and the blue slosyn is only 550 oz in so i thought it would make it easier on it
i suppose i could have used gas shocks some how and i still may
but the weight bench was free and i have a chop saw

[Ark1]

That is the correct way to go because the amount of lift provided stays constant. The gas shock has a linier but changing amount of lift. If you are direct driving the axis then you most certainly need some kind of compensation.

My table on my mill weighs 250 pounds but it has 60:1 reduction with 1100 oz servos.



Everyone has to start somewhere and it is the learning curve that I find kind of steep.

Not knowing servos from steppers or encoders, then software and then GCode.
Still learning and making mistakes.

What software are you going to use for the mill?

Ark1

[zymo]

That's not dumb, It's kick butt. I'm trying to retrofit an old machine myself, not that old, but about 20 yrs old. Any info I can get on retrofitting helps.

Thanks
z

[GM1G]

Originally Posted by Ark1 That is the correct way to go because the amount of lift provided stays constant. The gas shock has a linier but changing amount of lift. If you are direct driving the axis then you most certainly need some kind of compensation. My table on my mill weighs 250 pounds but it has 60:1 reduction with 1100 oz servos. Everyone has to start somewhere and it is the learning curve that I find kind of steep. Not knowing servos from steppers or encoders, then software and then GCode. Still learning and making mistakes. What software are you going to use for the mill? Ark1

right now i have unbuntu emc installed on one of the 15 pcs laying around
but one of the others i will put mach3 on
i want to be able to switch back and forth to play with them
not sure how thats going to work out lol
people love giving me computers so ive got a lot of them to play with

[GM1G]

got a couple slosyn 1390 oz/in nema 42 steppers off ebay for 40 bucks
used one on the rockford knee as the 550 oz/in slosyn just wasnt cutting it

hope u like it

[Ark1]

My TOS FN20 has a very heavy table. ( 250 LBS) I am using a 72 volt DC servo to move the Z. The tool does not go up and down but the whole table with the work peice. The servo has 1100 inch onces of torque and the motor turns 60 turns to the inch of travel. The acceleration is the kicker here as I have it down to about .5 inch per second. The issue right now I have with Mach and I will be correcting it shortly once I get a few things done with the mill is that if Mach3 sees more than 128 steps missed the drive goes into fault and Mach3 Zero's the axis. So imagine if your require 2" of travel on the Z and somewhere after an inch Mach3 changes the Zero and still tries to travel the full 2". Broken end mills here we come.

The other issue is load on the axis. My machine weights 2000 + pounds and my shop is kept above 35 degrees F. But at times it is a 70 degrees F. Well the gibs and ways get a bit sticky when cold and that added load makes my machine slow to respond and miss steps. Headed for the stops again. It takes a long time for that amount of metal to warm up.

Looking at what I have built, I now would have gone with a larger motor on the Z, but currently I am limited to the 77 volt DC power supply and the 80 volt Gecko 320x drive, for more power I would have to find a larger motor which may have a higher voltage that requires a different drive and power supply for the Z axis to move faster. For now I will keep my eyes open for a larger motor with 80 volts or less and just tune the parameters in mach3 down a bit so I don't miss steps.

Ark1

[GM1G]

got any pics of the machine?

postemup

[Ark1]

Sorry I never thought of including this link.

http://www.cnczone.com/forums/vertic...grade_cnc.html


Ark1.

[Ben Colby]

I'm experiencing similar z-axis problems on a Brother Drill&Tapping center I'm refitting with
Camsoft and servo motors. My Z axis motor and amp are not faulting but Camsoft sees
enough error when driving the Z axis up that it faults the motion controller and I get a free falling Z-axis (scary).

I'm looking into adding a counterweight to counter balance the Z-axis head. I like what you have done with your old iron (both of you). I'm trying to get as many ideas on counterweights as possible. Thanks for posting.

Ben
COBRO MFG.