1 Attachment(s)
Upgraded my z axis from plastic to solid steel. Screwed myself? Help!
Hey all, I have a zenbot 4896 router that is basically entirely plastic. And I want to start upgrading pieces to increase its rigidity. I do a fair bit of aluminum and even on some wood I get horrible chatter and machine vibrations pretty regularly.
I am running a 2.2kw water cooled spindle which is significantly heavier then the router it was designed for.
I am a welder fabricator by trade but I admit , I know very little about this.
The machine is all belt driven and the flex from the plastic , and the belts is quite a lot. I can push my spindle with my pinky while it’s cutting and it’ll cut a chunk out of the wall.
I upgraded to a ball screw 1605 I believe and the machine used Nema 23 steppers.
I can’t tell you what it weighs exactly but it’s 12”x6”x.5” steel flat bar x2.
My fit wasn’t done with a dial indicator or anything super precise. Just squares and stuff. When my plate is mounted to the slide blocks it moves fairy freely up and down the guide rails. And when attached to the ball screw it’s quite easily turned by drill.
However when I attach my Nema 23 425oz motor. It doesn’t go all the way up and down. It’ll go a little bit then whine heavily. The shaft is not spinning in the coupling I checked.
Could the motor just not have enough torque? Could It likely be my fitment? The plate moved freely up and down by hand.
In all honesty I lost quite a bit of ball bearings when I was making the piece. But it was just a cheap 300mm kit on amazon and I could buy new slide blocks to replace those if need be. Anyways. I know I’m all over the place here. But just wondering what direction I should go. Am I wasting my tome with a Nema 23?
Could I put a Nema 34 on my z axis and leave the other Nema 23’s? I’m using a gecko g540 with an ess
Re: Upgraded my z axis from plastic to solid steel. Screwed myself? Help!
Quote:
Originally Posted by
brianhatley
Hey all, I have a zenbot 4896 router that is basically entirely plastic. And I want to start upgrading pieces to increase its rigidity. I do a fair bit of aluminum and even on some wood I get horrible chatter and machine vibrations pretty regularly.
I am running a 2.2kw water cooled spindle which is significantly heavier then the router it was designed for.
I am a welder fabricator by trade but I admit , I know very little about this.
The machine is all belt driven and the flex from the plastic , and the belts is quite a lot. I can push my spindle with my pinky while it’s cutting and it’ll cut a chunk out of the wall.
I upgraded to a ball screw 1605 I believe and the machine used Nema 23 steppers.
I can’t tell you what it weighs exactly but it’s 12”x6”x.5” steel flat bar x2.
My fit wasn’t done with a dial indicator or anything super precise. Just squares and stuff. When my plate is mounted to the slide blocks it moves fairy freely up and down the guide rails. And when attached to the ball screw it’s quite easily turned by drill.
However when I attach my Nema 23 425oz motor. It doesn’t go all the way up and down. It’ll go a little bit then whine heavily. The shaft is not spinning in the coupling I checked.
Could the motor just not have enough torque? Could It likely be my fitment? The plate moved freely up and down by hand.
In all honesty I lost quite a bit of ball bearings when I was making the piece. But it was just a cheap 300mm kit on amazon and I could buy new slide blocks to replace those if need be. Anyways. I know I’m all over the place here. But just wondering what direction I should go. Am I wasting my tome with a Nema 23?
Could I put a Nema 34 on my z axis and leave the other Nema 23’s? I’m using a gecko g540 with an ess
You welded the linear rail that was not good, these have to be parallel and mounted on a flat machined surface or they will bind , you will have to use a indicator .0005" is what you need to set them up you don't have much to play with as far as alignment goes
Re: Upgraded my z axis from plastic to solid steel. Screwed myself? Help!
Drills can be pretty torquey (is that a word ?)
My Z axis with 5mm pitch ball screw can be moved up/down fairly easily by hand when the stepper motors are not powered. If you can not do this there is likely an alignment problem.
The alignment of rails to each other and/or rails to ball screw.
Re: Upgraded my z axis from plastic to solid steel. Screwed myself? Help!
Okay, so update. I’ve worked on it a little bit tonight shimming things up to where everything is flush ( the trucks and ball screw mount to spindle plate )
I took 1 set of trucks out so there’s only 2 total 1 on each side and it goes up and down under 100ipm, anything over there and it seems to bind and stall.
Still may be an alignment issue. I’m really against going back to the plastic belt driven z axis. I think I will save up and get premade z axis. I’m just not a machinist, nor do I have the right tools.
In the mean time I’m going to mess with it. What is the limitation of a 5mm ball screw in ipm? Am I overshooting my feed rate?
Just for curiosity, can I mix match motors? Nema 23 on my x,a, and y and 34 on my z?
Re: Upgraded my z axis from plastic to solid steel. Screwed myself? Help!
Is the ballscrew axis parallel to both rails?
Re: Upgraded my z axis from plastic to solid steel. Screwed myself? Help!
Quote:
Originally Posted by
brianhatley
Okay, so update. I’ve worked on it a little bit tonight shimming things up to where everything is flush ( the trucks and ball screw mount to spindle plate )
I took 1 set of trucks out so there’s only 2 total 1 on each side and it goes up and down under 100ipm, anything over there and it seems to bind and stall.
Still may be an alignment issue. I’m really against going back to the plastic belt driven z axis. I think I will save up and get premade z axis. I’m just not a machinist, nor do I have the right tools.
In the mean time I’m going to mess with it. What is the limitation of a 5mm ball screw in ipm? Am I overshooting my feed rate?
Just for curiosity, can I mix match motors? Nema 23 on my x,a, and y and 34 on my z?
You can do what ever you need to do with your motors mix and match anything you like, as long as the drive is suitable for the bigger motor you want have any problems
What you already made you could of had it machined on the mounting faces so there is nothing stopping you from making your own parts and having them machined where needed
Re: Upgraded my z axis from plastic to solid steel. Screwed myself? Help!
A screw that length doesn't need 2 bearing blocks on the screw. Try removing the lower block.
If perfectly aligned having 2 blocks on the screw should work but allowing one end to run free may give an idea of what's happening.
The BK bearing block is mounted 180 degrees to the usual arrangement but I don't think it is the source of the binding. It does make me wonder if the block is assembled properly. The other block is probably BF, it's hard to tell from the picture.
Why is there a plate between the bearing block and the coupler ?
Re: Upgraded my z axis from plastic to solid steel. Screwed myself? Help!
Quote:
Originally Posted by
cyclestart
A screw that length doesn't need 2 bearing blocks on the screw. Try removing the lower block.
If perfectly aligned having 2 blocks on the screw should work but allowing one end to run free may give an idea of what's happening.
The BK bearing block is mounted 180 degrees to the usual arrangement but I don't think it is the source of the binding. It does make me wonder if the block is assembled properly. The other block is probably BF, it's hard to tell from the picture.
Why is there a plate between the bearing block and the coupler ?
The bearing Blocks are correctly installed
Re: Upgraded my z axis from plastic to solid steel. Screwed myself? Help!
Update, I took the lower block off . Made it a lot better, when I took the bolts out, the block sprung up about .125. My plate must be pretty uneven ????
However it seems to work alright now. I still can’t get anything higher then 200ipm but I can live with what I have for now. Maybe I’ll just machine a new one out of aluminum.
Re: Upgraded my z axis from plastic to solid steel. Screwed myself? Help!
Quote:
Originally Posted by
brianhatley
Update, I took the lower block off . Made it a lot better, when I took the bolts out, the block sprung up about .125. My plate must be pretty uneven ????
However it seems to work alright now. I still can’t get anything higher then 200ipm but I can live with what I have for now. Maybe I’ll just machine a new one out of aluminum.
Machine the one you have, taking the Bearing off tells you how bad the alignment is bolting a rails and Ballscrew mounts like this to Hot rolled steel is a no, you could make an aluminum mount but steel is better if weight is not a problem
Re: Upgraded my z axis from plastic to solid steel. Screwed myself? Help!
Quote:
and I lost a bunch of bearings in the top slide blocks
Don't let the ball nut spin off the ball screw, the balls are tiny and you'll never find them all.
Don't ask how I know this.
Re: Upgraded my z axis from plastic to solid steel. Screwed myself? Help!
Quote:
Originally Posted by
brianhatley
I don’t have the machine capability to machine steel, I don’t think?
What would I use for a Cnc router to machine the surface on hot rolled steel? 1/2” end mill is the biggest I have. I have a mist coolant setup, my spindle is a 2.2kw water cooled minimum rpm is 7200 but I’ve been told the torque is pretty low at that rpm.
You would get a machine shop to machine it where needed, and no you could not machine with what you have
Re: Upgraded my z axis from plastic to solid steel. Screwed myself? Help!
Quote:
Originally Posted by
brianhatley
I don’t have the machine capability to machine steel, I don’t think?
What would I use for a Cnc router to machine the surface on hot rolled steel? 1/2” end mill is the biggest I have. I have a mist coolant setup, my spindle is a 2.2kw water cooled minimum rpm is 7200 but I’ve been told the torque is pretty low at that rpm.
Definately dont try to machine steel you will smoke your spindle, and it wont end well for you. Will make all kind of awesome noises with a good amount of chatter on the side. You can machine a piece of alloy though just practice first before you dig into that piece you will have bought. Im on version 5 of my machine. Used the first timber one to make the second, then so on. Those are some mighty big tack welds on those rails me old mate and that would have pulled them over somewhat as well. Bolts are good because you can take things off again without a grinder. But once you get things running better you can make yourself a nicer Z axis, with holes all aligned etc. The Nema 23s are good little steppers. And some people run them on 80vdc to get the most out of them. Like the other guys say, its all about alignment when things bind.
Re: Upgraded my z axis from plastic to solid steel. Screwed myself? Help!
i just realized im only running a 24v power source in my control box , the one that came with the router. Im wondering if that would explain the loss of torque in my motor?
Also as a side note, since the new z axis has increased substantially in weight, when my machine changes directions the whole z axis wobbles because of how much flex there is on the belts.
It has however definitely made a very large difference in the deflection right at the spindle, so that i'm really happy with.
