Plasma cutter advice please!

tommy, you are a fountain of genius.  period.  i have always seen your threads on retrofits and rebuilds, but i never really paid much attention to the plasma sided of it because i didnt have a plasma.  the closest i ever came was with @pinder 's monokrom gui and trying to figure out how to use it for a router.  those machines are freakin amazing.  like seriously.  i dont know how you havent given corps like avid and laguna a serious run for the money!

tommylight wrote:

Don't get me wrong, it will probably work without issues, but the safety margin is non existent, and i insist on safety always.

done.  just thought a premade solution would be simpler.  my electronics ability is limited to just enough to get me in trouble, so i defer to the experts for that.  altho, i do find it ironic that a dude that gantry surfs and uses a plasma table as mobile lift lectures people on safety 

you've sold me on keeping the belts.  that is going to save me so much coin.  so i see that you use supported round rail instead of square rail.  is it a cost or performance issue?  what size of belts are you using on those machines?  mine is going to be exactly half of one of yours - 1015. also curious if you are reducing because of the weight of the gantry rather than driving it directly.  i had also toyed around with the idea of using everman belts, but it would really depend on where my belts actually lie.  ill be using hgr20 rail mounted vertically on the sides of al extrusions (everything from the bed up will be aluminum)  this gives me around 30-35mm of space between the rails and gantry plate that i would have to figure out a way to keep the belts from floating.  i also could mount the motors vertically and run the belts just under the rails.... hmmm.  ill have to think on that, i prefer simpler solutions, but i tend towards overthinking 

tommylight wrote:

I am a dumb f@k!

funny, thats what i tell people about myself.  my garage looks like a nasa at home kit, yet im still broke and go to a crappy job every day!  but i seen your machines, and dude they are slick.  ive seen some peoples home built machines and they look cobbled together.  but yours could be mistaken easily for something like a shopsabre or laguna!

im using 15mm 3m belts, and i think ill stick with them.  i already have a pile of belts and pulleys.  ill keep it the same for all axes.  im not a fan of mixing and matching parts, i find its easier to buy in bulk and use the same parts on all axes.  plus it makes calibration easier.  

ill give the reduction a thought.  on the 5x9 i am building, i am reducing 1:4, but it is holy hell to find the right pulleys and belts.  its either the id bore, width, or tooth count, but can never find what i need.  have a set of pinion gears that took forever to find, but i need a keyway in them and the local shop wants 300 to put 3  3mm keyways in 3 gears.  thats ridiculous 

and yes i have a printer, a very nice one that i built.  what parts to do you print?  and they are stout enough?

thats pretty ingenius using 3d printers for the caps and covers.  i have created a bunch of t emplates for cutting caps out of 3mm aluminum for all my covers.  so this is the machine that i am replacing: 

 



its one of my first big designs and was before i really thought on a bigger scale.  it is good for what it is, but im going to basically hawk all of the parts from it to make this plasma cutter.

 
  

and this is the machine that i will be cutting all of the parts with. it will also be the starting point for my design as well, minus the ballscrews now.  and of course a steel base.  i am really proud of this machine and it works amazing and has a decent cut area for its size too.

 

and this is the printer that i will be using to as well.  core xy and prints super fast and reliable.  cant ask for better!

so today i ordered my rails and some 10mm aluminum plate to get started on the gantry.  after reading through your posts, i am envious of your ability to get aluminum so cheap there.  its easily 2-3x more expensive here.  now i just need to find myself a good pulley reduction set that wont break the bank.  

For 2.5m travel on plasma x axis can use 30mm wide htd5m belt
or must go with rack - pinion?
What about high lead ballscrew (32mm pitch)?
I will use aluminum profile shown in image.

Rapids 30m/min are ok or can i go upto 60m/min ?
I will use servo motors with reduction and because i need good acceleration
that translates to a lot of torque so i think more stiff belt htd5m 30mm wide is better.
The motor with the pulley will be at the side of profile(not moving with torch) and belt will do loop inside the profile
and outside where the ballscrew is now in the photo so belt will be 5m total length.

@tommylight if you you want this profile check it
vallder.com/product/cnc-x-axis-alu-profile-200x96/
also has a china torch yk that cuts very good.