Size reduction

I had my Burley MPCNC for about a year now, and I want to improve its rigidity so I can go a little faster and cut more accurately. I’m at a working size of 35" x 25" x 2.5". I have midspan supports on the 35". I’m planning to take it down 10" to 25" x 25" x 2.5". I’m pretty sure I don’t need the size. Questions:

  1. Is it worth doing this alone or should I just rebuild a primo at this point?
  2. How much improvement am I likely to see in terms of feeds and accuracy?
  3. What is the most efficient way to do this. I’m thinking
    a. disconnect belts on axis i’m cutting down
    b. unloosen feet on side away from my drag chain
    c. undo belt on end that is moving and remove the stepper wire that is in that tube
    c. move feet to new location
    d. cut the two outer tubes with hacksaw / angle grinder (maybe hack saw to control heat better haha)
    e. cut inner tube to length
    f. reconnect everything…
    Am I missing anything? seems like I can do that without dismantling the center.

1-If it works fine then no need to redo everything, just keep everything and shorten your tubes.
2-Depends on how bad it was in the first place and what material you’re planning to cut. You probably have much more to gain improving your CAM settings than tweaking your machine to be honest. Most of the time the issue isn’t the machine but the user’s ability to find proper settings in CAM.
3-Seems all right. You also might have to tweak the firmware a bit, depending if you had some custom mods related to machine size in it.
If you already built the CNC in the first place then no need to overthink it, it’s pretty straightforward.
You can even do it the lazy way and just losen a bit the corners and rollers screws, move the feet without removing any tube, secure the feet in their new spot and then cut the excess tube and excess belt, shorten drag chains, etc…

Personally I’d loosen all four corners and slip the tubing out that you want to cut rather than try and cut it in place. You might have to cut the zip ties for the perpendicular belts to make this work. I expect the reduced frustration in getting a good cut on the tubes will more than offset the minor bit of work of threading the tubing back through the trucks.

Without proof, I believe you will see little difference in common wood cutting, but some difference in uncommon cutting that taxes the machine…things like milling aluminum or cutting traces in a circuit board might show some improvement. If you go ahead and reduce the size, I’ll bet the forum would be interested in some before and after tests that examine speed, DOC and accuracy.

The Mostly Printed CNC ( MPCNC ) is a platform to precisely control motion. This can easily be a milling machine, 3D router, 3D Printer, Laser Cutter, vinyl cutter.

Not sure of your point. He is making the distinction between the Burly version and the Primo version of the MPCNC.