Jump to content

Entry for June 2018's Guitar Of The Month contest is open!
ENTER HERE!

MiKro

cnc rebuild

Recommended Posts

1 hour ago, ScottR said:

It still impresses the hell out of me that you built this from scratch.

SR

Thanks Scott,

I remember when I started it years ago  (2005). George a friend of mine showed me a picture of one a friend of his was building.. I used that picture as my guide. his was much lighter weight :)

I went through 3 iterations of  mine,.first one used 1/4-20 all thread for the screws. That sucked, then went to acme screws, that sucked finally with the ball screws. The basic frame was the same as it is now. The 1/4-20 gave me max IPM @ 15  the acmes IPM @ 37, then the ball screws were IPM @ 250, many other hurdles with harmonic resonance problems. but I managed my way through. The learning curve was very steep and no help from any locals other than my machinist friend who taught me many lessons. Lot's of broken end mills, parts and cussing. LMAO!! I also started out with a porter cable finish router. Now I use a 690R with a PID control so I have variable speed from 5000 -30000 RPM all computer controlled.

It was and has been worth it though.

Mike 

I have done many things on this machine over the years. here is one I did for my mother. about 7 years ago

lastsupper.jpg

  • Like 2

Share this post


Link to post
Share on other sites

Here it is with the original finish router I used. I was making a 4-12 cabinet. :) God that thing was loud running at 27K plus. Now I barely run at 10K to 15K on everything. Speaking of routers I need to go get a set of new bearings for mine. I have the upper, just need a lower..

mk

oldcnc.jpg

Share this post


Link to post
Share on other sites

So I am removing the extensions on the gantry. which will yield a reduction of approx 5lbs.. Which using a fulcrum formula. with a ratio 5.5 to 1 that should reduce the flexing weight  at the rails by approx 27lbs. That should help on flex when direction changes in X axis as well as not as much load on the stepper.motor. :) Not.  as much as I would have liked but it is better..

mk

exten.jpg

Share this post


Link to post
Share on other sites

Well it is alive again. :)  Some small things to do before starting adjustments.. That will wait until Friday. It's scotch time. Been a long Hot day.

edited to add:

Been air cycling the CNC. while enjoying my scotch.

In 2d it's running at 200ipm no problem. Maxed out out 300ipm for rapids  every now and then a stall will back that off to 250IPM. I could change the resolution and most likely get 400IPM. no need as I have lots of time.

Doing a 2.5d  test now. running at 180IPM  so far after 30mins no problem. I'm happy. This means that most stuff cut at 100 to 130 IPM will be no problem. :)

MK

  • Like 1

Share this post


Link to post
Share on other sites

going to get a machinist surface plate tomorrow. Need to have something super flat to do the setup. I have tried plate glass 3/8" it is not flat by any means.

On a good note I rerouted all of the cables today,. very happy with those results. Now they are out of the way and should not be a problem and allow full movement without any binding..

 

Edited to add:: Picked up a machinist plate. Man that helps. Took awhile to level it to the X axis and Y axis. Trying to tram this thing has been a bitch. Got it in at 0.003 on Y and 0.004 on X..in 6 inches. That works out to about 0.001 in 1/2" so should be good enough for a few days That is workable for this week. I have some things I have to get done for someone by Tuesday so I will make do and then revisit the adjustments. ...

mk

Share this post


Link to post
Share on other sites

So parts done. now back to adjustments.. Checking for backlash I have found that my X axis ball screw is off by 0.010" my Y axis is off by 0.006" This appears to be wear on the ball screw/ball nut assemblies. When New they were within 0.002".. So I have ordered new ball nuts for both axis. My plan is to use these in conjunction with the old ones and have them work as anti backlash nuts. Ball screws normally do not have this. Usually only acme lead screws have anti backlash nuts with the ability to adjust out the back lash. This in theory for me should result in as close to zero backlash as possible.

I'm now waiting on parts. will also be using a 12" DRO to measure spindle travel lengths to set steps.. The one I will be using is 12" with a 0.0005" resolution and accuracy within  0.0003" Using this should also help with the accuracy as it is more than enough resolution for wood working.. Basically this should get me in the 0.xxxxxxx  range of steps based on my settings for step resolution. As .my step resolution is 3 decimal points from my measuring resolution.

mk.

 

Share this post


Link to post
Share on other sites

Almost time to make some sawdust! And it sounds like each grain of sawdust will be uniformly sized and shaped to within 0.001" of each other.:)

SR

 

  • Like 2

Share this post


Link to post
Share on other sites

Yep in the process,of getting ready to make micron sawdust

Also I have rebranded my guitars. from now on they will be Forge guitars

 I own the website, and  now. in process of llc. I have 5 orders for the TZ   as it will be known, Yep the BoDiddly style. I made.. I have already sent off the forms for the copyrite on the logo  I plan on offering with 24.5 to 25.5 scale in 0.25 increment conversion necks..as an option since they will be bolt on. necks.

MK

 

 

FORGE2A.jpg

 

Share this post


Link to post
Share on other sites
47 minutes ago, ScottR said:

Damn. You're going to have to teach me how to sell.

Love the logo!

SR

Hell I don't know how to sell. My workhorse guy does!!! He is a working musician. Also has been in retail for over 30years.

mk.

Share this post


Link to post
Share on other sites

So my new ball nuts came in today. Changed out the old ones to the new ones before I start with making anti-backlash nuts from the old units with wear, I tested the new ones. Low and behold I now am back to 0.001" backlash on X and Y at the ballnut,  Z is still fine.. :) I will. wait on doing the anti-backlash nuts for the time being. Now back to squaring and tramming adjustments.

MK

  • Like 1

Share this post


Link to post
Share on other sites

So I just finished squaring. It now cuts 4" squares with a diagonal corner to corner of "0.006. Damn better than I hoped :) Tramming is still off some, X is within 0.002" in 5 inches and Y is within 0.003" in 5 inches.. Have some very faint witness lines when surfacing. with a 2 inch surface tool. Can feel a few spots but mostly not at all. These appear to be more from machine flex than anything. I could most likely get it a little better but I am thinking it is time to not worry about this anymore and start doing things. Give it some wear time and revisit the setup again in a few weeks..

MK

 

bed.jpg

Share this post


Link to post
Share on other sites
1 minute ago, MiKro said:

I am thinking it is time to not worry about this anymore and start doing things. Give it some wear time and revisit the setup again in a few weeks..

MK

Yep. It sounds like you are literally splitting hairs at this point.:)

SR

  • Like 1

Share this post


Link to post
Share on other sites
3 minutes ago, ScottR said:

Yep. It sounds like you are literally splitting hairs at this point.:)

SR

Yep I agree it is a CNC router not a  CNC Metal milling machine. :)

Share this post


Link to post
Share on other sites

"Oh, this must be one of those CNCs where you can throw wood into it and a finished guitar falls out of the other side with no work involved!"

Said nobody who has experience with CNC.

  • Like 1

Share this post


Link to post
Share on other sites
10 hours ago, MiKro said:

Yep I agree it is a CNC router not a  CNC Metal milling machine. :)

 

Easier to split a thick Mediterranean one.

  • Like 1

Share this post


Link to post
Share on other sites
9 hours ago, Prostheta said:

"Oh, this must be one of those CNCs where you can throw wood into it and a finished guitar falls out of the other side with no work involved!"

Said nobody who has experience with CNC.

Damn Skippy!!

Mine is now voice activated as well. I can tell it to make a tele with 25in scale, 1 single coil , 1 humbucker a preamp, active pickups and various other things or any other shape I desire and a few hours later Presto All i have to do is spray some finish on it and go, since no sanding is required. I just install the hardware after the finish is dry.  Man it sucks to have to work at this. LMAO!!!!

MK

  • Like 1

Share this post


Link to post
Share on other sites

Well here I am again after some use it is definitely showing problems again.. So starting over and many upgrades coming. Will be using some of the original frame, electronics and the ball screws.

So after more time still chasing demons in the cnc after it is being used, I am tearing it down again completely. The hell with these damn old linear motion bearing carriages I made 10 years ago. I have ordered me some new THK slides and blocks for X and Y axis. Also will be making a new Z axis as well with 20mm Linear Rods and bearings.. Updating it with full tramming adjustment. Making some changes to my Ball screws so I have better control of thrust bearing adjustment as well.  I recently repacked the ball nuts again and they came out at 0.0005 backlash.

Then If all goes accordingly I will most likely update to a VFD and Water cooled spindle.

Woohoo !! Another 2 months of rebuild.

Mike.

Share this post


Link to post
Share on other sites
On 6/30/2017 at 9:04 AM, ScottR said:

You just can't stand not having a project going on, huh.....I know the feeling.:)

SR

Damn Skippy!! Really though I have enough to do and need this damn thing working consistently. Which it is not. If this doesn't fix it then I will make a new frame. Basically a new machine. Part of this upgrade is to the frame though so hopefully All will be within my expectations. ???? We will see.

MK

 

just some of the new parts I need to machine.

 

bearing_block2a.jpg

 

.

Share this post


Link to post
Share on other sites

So it is now nothing but parts again. Totally taken apart. Soon the Rise of the Phoenix. LOL!!!

 

cncapart1a.jpg

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×