Messages

91

General Mach Discussion / Re: Z Axis Help Appreciated!!!!!

« on: January 22, 2012, 07:12:42 PM »

Just thought I would give an update!!!  I have run the router hard this weekend non stop!!!  Both Saturday and Sunday.  I haven't had as much as a glitch.  Which leads me to believe that if I do anything is purchase a ball screw to reduce friction.  All of this really gets me motivated and thinking about the next machine!!!  I am wanting to build one with a fourth axis, just gotta keep it under the radar as my wife will probably not be real happy.  That's why as men we must keep what I call mad money hidden!!!  Just wanted to let you all know that I appreciate all of the help.  This forum rocks!!!  Anyone that can read can find an answer to just about anything DIY cnc related.  Keep posting any input that you may have, as I am always keeping check.  Soon I will be posting some of the work I am doing.  Some things I can't post as they are prototype and are currently going thru the patent process.  (Things that I am working on for other PEOPLE!!!!)  Some of the other stuff I will be glad to show.  Any ideas on where to post them?  General discussion or some other area?  Everyones help is greatly appreciated!!!!

92

General Mach Discussion / Re: Z Axis Help Appreciated!!!!!

« on: January 21, 2012, 10:24:41 PM »

Gerry,

What am I looking at cost wise in swithching to the Gecko

93

General Mach Discussion / Re: Z Axis Help Appreciated!!!!!

« on: January 21, 2012, 10:23:20 PM »

If I could get them running a 200 ipm I would be thrilled.  Dont think its an issue on x and y just maybe z.  Probably wouldn't be an issue then if I would go ahead and put a ball screw in.

94

General Mach Discussion / Re: Z Axis Help Appreciated!!!!!

« on: January 21, 2012, 05:53:42 PM »

Wow!!!

Thanks for all of the input so far!!!  I am going to try to cover all aspects and replies, so bare with me this is not my area of expertise!!!  I am running a 48v 12.5 amp power supply.  I looked up my motors, but could not find a torque curve chart.  Yes I am aware and new from the start that a ball screw would be way more efficient, but like most I am on a limited budget and was sure by now something at work would have croaked and I would have had one.  It is a five start acme screw.  Originally I tried the one to one ratio and when the machine hit rapid it made a crazy noise and slipped..  Of course all of these test were done basically cutting air.  The weight of the spindle assembly if I had to guess would be in the area of 10 to 12 pounds.  I think the amp max on my drives are 3.0.  They are KL-4030's.  Hood, I understand what your are saying so I am tweaking on that as well.  My hats off to all you guys, as you make me look like a charity case in comparison!!!LOL(That's why I'm Here!!) By the way the amp max on the drives are 3.0 amps I believe. That's what they are set at.  Everybody enlighten me here if I am wrong.  If you increase resolution you loose motor torque?  That was my thought process for going to the larger drive and motor.  This motor slippage that I have seen has been non predictable.  When I thought it would slip it hasn't.  When I thought it shouldn't it has.  Out of fifty runs its only done it maybe three times.  Am I pushing the envelope here?  Should i just deal with it when happens and go on?  I would put a torque wrench on it, but I don't have anything that small.  For the most part I have been thrilled with the machine overall, but every once in awhile it drives me bonkers.  The guy that takes care of the electrical side of things that I work with is telling quit jacking around and put servos with encoders on it.  I really don't think my machine is that bad and am just trying to fine tune it a little.  Please guys, feel free to add more input.  Don't worry about offending me as I realize that I am not an expert or I wouldn't be here.   All of your help is appreciated!!!

95

General Mach Discussion / Re: Z Axis Help Appreciated!!!!!

« on: January 21, 2012, 11:39:16 AM »

Sorry,

I'm having trouble getting the picture uploaded.

96

General Mach Discussion / Z Axis Help Appreciated!!!!!

« on: January 21, 2012, 11:34:16 AM »

Hey Guys,

I want to get your thoughts one more time if I might!!!!  Its been a little over a year since I tackled building my own cnc wood router.  For the most part have been been extremely pleased, and everything has done exceptionally well.  I did run into an issue with z axis motor slippage right out of the gate.  It didn't really supprise me at first because I had concerns that this might happen.  I build and design equipment at work and alot of my design was based around some spare parts we had from older equipment that had been decomissioned.  LM guide and things of that nature that really elevate the cost of building one of these.  As I began calculating the cost of this machine I opted to make the spindle lead screw out of a precision acme screw with an acetal anti backlash nut.  Once assembled I realized that there was a large amount of friction which in turn would lead to loss of motor torque.  I didn't really worry about it much, as I decided that eventually I would end up with an old servo that I could rob the ball screw out and retrofit into my application.  When I started running the machine I started loosing steps immediately on the z axis.  I changed my timing pulleys to give larger gear reduction and then decreased the resolution on my stepper driver.  The stepper motor is a 425 oz. in. in case any of you are wondering with a one and five twist 1/2 precision acme screw.( I believe that's correct on the acme screw, its been awhile!!!!)  Once the motor was retuned and calibrated that took care of most of my problems.  I turned down my rapid speeds in my cam program and haven't had many more issues.  I had no intentions of making what I actually have been on this machine.  Funny how things work out.  Gunstocks seem to be pretty lucrative to me and fun.  My initial thought were name plates and maybe some small relief work.  Now that I have bored you all to death I will get to the point!!!!  When finishing one of these units there is an extreme amount of time with start and stop points and moving to them.  So when you combine this with slow rapid movements that really creates a long run time.  Now to avoid alot of sanding you only finish with ball so fast, but rapid can be as fast as the machine can stand.  X and Y can rapid at 200-300 IPM with no slippage, but the best I can do on Z is about 90.  Now in my cam program I can only set the rapids overall, not by individual axis.  So in turn this slows everything down.  I have checked every possible potential failure that could cause the z to slip and cant find anything it could be except the motor and that there is just to much mass to be shifting very quickling with the additional friction of the lead screw nut.  That ball screw I was waiting for hasn't happened yet so I have decided to go with a larger stepper with its own power supply.  I thought about isolating the Z axis with its own power supply and trying that first.  I haven't put an amp clamp on it to see what its pulling or if its getting the power it needs.  I bought a four axis kit from Keling and all steppers are using the same power supply.  Y gantry are two steppers slaved together  and X is just one stepper.  I am enclosing a picture of my z axis assembly so you all can see and maybe shed some light.  I am certain I have over killed the replacement stepper motor.(1600 oz. in)  It want to increase the resolution a little more than on the previous and just want to be sure I have enough power.  Everyone's continued  help on this forum is greatly appreciated!!!!

97

General Mach Discussion / Re: Mitsubishi MR-J2S-40A and Servos!!!

« on: July 13, 2011, 09:53:37 PM »

Hood,

Thanks for the input.  We have got several mistushbishi Q racks, processors and I/O Cards chocked full in a cabinet at work and I am sure I can get one.  The only problem is I am not very familiar with that type of programming.  I do have an Allen Bradley Micro logix out in my shop right now off an old machine but it was pretty simple not for sure about the I/O count on it.  I just thought that since these units had gear heads as well thought I might be utilize them.  I do help the programmers calculate all the ratios on these units but as far as interfacing them with a plc it might be over my head.  I have never let it stop me before but I will have to ponder this one.  Just thought this may make a pretty slick machine if I could pull it off, but I don't want to put a boat load into  it just to salvage some servos.  If you don't mine me asking, what type of plc's are you using.  I am more familiar with the allen bradley but I don't have any of the software.  Any input would be appreciated.

Thanks!!!

98

General Mach Discussion / Mitsubishi MR-J2S-40A and Servos!!!

« on: July 12, 2011, 11:13:43 PM »

We are doing a retool on a machine at work and are going with the next latest greatest Mitsubishi Amps and Servos.  That being said I will be able to acquire enough of these to build another machine.  My first machine was built with stepper motors and even though I haven't had any issues, I would like to build a larger one with these servos.  The drives are Mr-J2s and I believe that the motors and gear heads are HCkfs43.  I was curious what type of Bob to incorporate  with this build.  My other  machine uses a C10 bob, and I haven't done enough research yet to see if it is feasible for this one.(Voltages, ETC.)  I typically do the mechanical design at work and the build and leave the electrical to the programmers.  I had a blast building my last machine from start to finish but did pull my hair out a few times due to ordering some components that was exactly the best for my application.  I was hoping to get a little bit better plan together for this and avoid some frustration.  Any input would be greatly appreciated.

99

General Mach Discussion / Re: G-Code Help!!!

« on: July 06, 2011, 10:10:49 PM »

Gerry,

I am enclosing the same file part post with a Mach 3 Sherline Post and a Mach 3 Post.  I believe that you are correct, in the plain Mach 3 post the L is not in the g-code.  I am going to show examples.  Thanks for the help I will try this on the machine tomorrow.  Hopefully it won't affect the 3d contouring by changing the post.

Mach 3 Sherline

N1 G00 G49 G40.1 G17 G80 G50 G90
N2 G20
N3 (Breakchip Drill )
N4 M6 T3
N5 M03 S18000
N6 G00 G43 H1 Z1
N7 G01 X1.7548 Y-2.2978 Z0.2670 F100.0
N8 M8
N9 G73 X1.7548 Y-2.2978 Z-1.0964 R0.1 L0.0 Q0.1
N10G80
N11 G01 Z0.2670 F10.0
N12 G73 X1.1053 Y-0.6981 Z-1.0964 R0.1 L0.0 Q0.1
N13G80
N14 G01 Z0.2670 F10.0
N15 G73 X4.0235 Y-0.9017 Z-1.0964 R0.1 L0.0 Q0.1
N16G80
N17 G01 Z0.2670 F10.0
N18 G00 Z1
N19 M5 M9
N20 M30

Mach 3 Post

G00 G49 G40.1 G17 G80 G50 G90
G20
(Breakchip Drill )
M6 T3
M03 S18000
M8
G01 X1.7548 Y-2.2978 Z0.2670  F100.0
X1.7548 Y-2.2978
G73 X1.7548 Y-2.2978 Z-1.0964 R0.1 Q0.1 F10.0
G80
G01 Z0.2670  F10.0
X1.1053 Y-0.6981
G73 X1.1053 Y-0.6981 Z-1.0964 R0.1 Q0.1 F10.0
G80
G01 Z0.2670  F10.0
X4.0235 Y-0.9017
G73 X4.0235 Y-0.9017 Z-1.0964 R0.1 Q0.1 F10.0
G80
G01 Z0.2670  F10.0
G00 Z1
M5 M9
M30

100

General Mach Discussion / Re: G-Code Help!!!

« on: July 06, 2011, 09:59:40 PM »

Sorry guys, the g code is somewhat over my head.  I reference it at work for x y z moves and look at the types of moves that it is calling, but I have to refer to chart to understand what they all mean.  I am going to post through some of the Mach 3 post processors I have and see if the g code files turn out any different.  I appreciate the help and would be glad to share the results if you would like.  Should have learned G code first but didn't have the opportunity.  Crash coarse here we come!!!!