# My First Cnc Job



## rpmMan (Sep 22, 2015)

Been lurking on here for a while.. earlier this year I bought an acer knee mill that the owner had been converting from an anilam control to mach 3.
I have spent a few months cleaning, totally rewiring and troubleshooting.. getting up to speed on gcode, gecko drives, warp9 smothstepper, cnc4pc bob etc etc...

Anyways I finally have the machine more or less functioning the way I believe it should.. This weekend my son in law is going to do the iron man race in Chattanooga so I thought it would be a good stress test of the machine to make an ironman medallion out of a hunk of steel..

Thanks to steve on here with his tips on ez machine shop and d2nc I finally got a finished product...


----------



## JimDawson (Sep 22, 2015)

Welcome to the world of CNC!  Happy to hear it's running.  Good luck to your son in law.


----------



## rpmMan (Sep 22, 2015)

thanks jim.. it has been a bit of a struggle and I was starting to doubt whether it could be done..currently have all three axis's working ..

the piece looks much nicer than the pics.. a 5.75 x 5.5 x .25 hunk of hrs... with my attempt at mimicking the iron man logo.. it is close but not perfect by any means..
I was able to really stress the system as the m pocket is 5 passes at .02 per pass as is the circle.. using a 1/4 in carbide end mill .. the m cut took approx. 50 minutes..
I now have a bit more confidence in how things are set up and am somewhat impressed at how well it is working..

The lettering on the back side was done with an old carbide 1/8 inch stenciling machine cutter (looks like a d drill)  that I had saved from years ago..

At some point I will post some details of my setup and configuration .


----------



## Wreck™Wreck (Sep 22, 2015)

Looks nice, is the Z axis under control? The only CNC knee mills that I have ever used are Bridgeport EZ Trak's, the Z axis was manual and not controlled.


----------



## rpmMan (Sep 22, 2015)

yes the z is controlled and is repeatable to 1 - 1.5 thou according to my dro mag scale.. this machine has a 50 in table with 16 in travel in the y and z and 34 or so in x..
currently running the x and y at 30 ipm and the z at 3 .. working fine so far.. originally it had a 1/2 in timing belt with 1 to 1 pulleys and a ball bearing tensioner .. was no where near stout enough I changed it out for the #35 chain drive with a 2 to 1 ratio .. so far so good.. and it is very sweet to type in g00 z 10 , get some coffee, etc..

rich


----------



## countryguy (Sep 22, 2015)

Really good work Sir Welcome.  It is a great comfort when you refurb/repair and then know the machine inside amd out!    Glad it is up and running!    So how much space is left in the garage?  And what is next on the list to fill it up.  Lol.


----------



## countryguy (Sep 22, 2015)

Ps.  Yikes 16" on Z.    I am jealous.   I rebuilt a ymc-30 taper with the Ajax-centroid setup.   you now get to have a lot of fun as winter approaches.    Keep the postings going here!  Love to hear and see the stuff from everyone.


----------



## JimDawson (Sep 22, 2015)

An interesting Z setup.  I have heard of it being done that way, but yours is the first example I've seen.  Your mill looks much like mine and looks to be the same size, looks like the main difference is the V ways on the Y axis, mine are boxed ways.

Do you still have manual capability?


----------



## rpmMan (Sep 23, 2015)

tks all... jim no manual control (crank) for the z ,x or y ..  the only option for the z at this time is the motor and or a pair of vice grips..
the person I bought it from had just got started trying to get it working from where it was left off by the person he bought it from..  it had very little documentation except for some hand notes detailing the x, y motor amphenol connector pinouts etc.
it still had 2 large (30x30 or so anilam control cabs mounted on each side).. the wiring was a butt splice disaster..the person who started the mods I believe did the z mod.. using a timing belt.. it took so much pressure to keep the belt from climbing out of the sprocket teeth they had slightly bent the shaft a bit.. anyways I removed the shaft and trued it up enough to mount the chain pulley.. the original anilam x and y stuff was done very nicely.. 1 in ball screws , and beefy 4 brush servos with tachs, and 1000 count quad encoders.. of course the gecko drives only handle the a,b encoder outputs..

The z drive is kl34-180-90 motor with an unmarked gearbox ..

my next project is to redo the z drive mounting and get it enclosed to eliminate the pinch points.. not sure if I will be able to rig up some sort of crank or not..

rich


----------



## Wreck™Wreck (Sep 23, 2015)

Not to knock your setup here but that roller chain drive will have a lot of  lash when changing directions in Z.


----------



## rpmMan (Sep 23, 2015)

wreck.. I hear ya.. actually it is worse than just that.. the shaft drives a bevel gear which turns the knee acme screw .. when I put it together after removing the shaft there was a noticeable back and forth slop in the bevel gear engagement.. not much and I did not try and measure it.. but noticeable.. im guessing that is my limiting factor.. I did think about putting some sort of spring loaded idler on the chain though I guess it would need two , to handle the 2 directions.. so far im pretty happy with how repeatable it seems.. I did measure my cuts , the program did 100 thou in 5 steps for both cuts returning to safe z of .1 between each step and returning home between the 2 cuts.. I measure a depth of .108- .109 for both cuts.. and this is on a piece of hrs that barely fit in my 6 vice and I intentionally did not face it as I wanted the raw iron look.. and did not take real care in setting the z zero .. so that could easily be off a thou.. the piece most likely was bowed a bit from vice pressure.. anyways when I redo the mounting I may add some tensioners as the chain will certainly stretch over time..

rich


----------

