I have a project involving 3/4-1” maple with loads of rounded cuts (think big jigsaw piece) and I need to put a 1/8 roundover on all edges. I have not attempted this on the maslow - seems like it would be pretty straightforward - I plan on fixing the piece to a backing plate so its stays in place after initial cut but wondering if there are tricks or challenges that might arise that some of you may have experienced. Id have to change router bit during process and not sure how to best handle this - I have limited experience with my maslow - mostly have used it to for straight cuts on ply
1 Like
I think I would make 3 gcode files, 1st would cut 1/2 way through in the “jigsaw” pattern, then change the bit to the rounding bit, and round off, then go back to your cutting bit and do a final cut leaving tabs where appropriate. Of course you would have to adjust depth each time.
You could also do it with only 2 files. 1st to cut with tabs, 2nd with rounding bit.
1 Like
Ian Abbott wrote:
I think I would make 3 gcode files, 1st would cut 1/2 way through in the
“jigsaw” pattern, then change the bit to the rounding bit, and round off, then
go back to your cutting bit and do a final cut leaving tabs where appropriate.
Of course you would have to adjust depth each time.
the roundover path will probably also need to be offset from the edge of the
cut.
David Lang
3 Likes
why is that? assuming the bits are the same diameter at bottom wouldnt it align?
I have not done multiple files in same piece - how dies it know to start in exact same place? id imagine I have to loosen things to change the bits though I havent tried to do it when its all under tension
Yoshi wrote:
why is that? assuming the bits are the same diameter at bottom wouldnt it align?
roundover bits commonly aren’t the same diameter. But your CAM program should
handle this.
David Lang
1 Like
Yoshi wrote:
I have not done multiple files in same piece - how dies it know to start in
exact same place? id imagine I have to loosen things to change the bits though
I havent tried to do it when its all under tension
the maslow is very repeatable, you should be able to cut, release tension, apply
tension, and cut again with good alignment between the cuts.
David Lang
2 Likes
I have been thinking about doing a roundover run on the cnc, because it should work just fine. It would be a seperate g-code file, because it is going to be a different bit, and you’ll want to offset that job to be the edge of the bit, not the center. Outside cut, plus probably 2mm is my guess. The reason for having to offset the bit is because a roundover is 1/8" from the center of the bit, but it is significantly wider than 1/8". Even using a roundover bit on a router by hand, you want to set the bit to just skim the outside of the workpiece and not deeper than the blade width, unless you do a couple passes. I haven’t tried it yet, because I can just do it on the router table in a few minutes, or do it by hand with a cordless. It’s much quicker, lol.
I have a couple of suggestions for you that works for me. My machine is an M2, so I have chains instead of belts. It’s a bit different, but the same principles apply.
I mount my workpiece to the spoilboard using painters tape and glue. I put tape on the spoilboard, and tape on the backside of the workpiece, and then glue the back of the workpiece. I skirt around my workpiece with equal width boards (I have a collection of boards that are just dedicated to the M2. Anyway, it works great, and holds a piece with excellent strength. I typically have to pry it up with a scraper tool, but once it is off, you just peel the tape off and you’re done.
I can change bits at any time without having to retract belts, so I may be wrong in what I say here, but my machine will keep it’s settings. My XY zero will not change. It is accurate and repeatable. On a gantry style machine, or quite possibly also with the M4, I suggest changing the bit, then Homing the machine, and then move your spindle around the workpiece to see if it lines up. Don’t forget to reset your Z-zero after changing bits.
One other trick I have used is to cut a wee hole at work zero. No matter what happens, I can always line the machine back up with that hole and reset the job, and it will work.
2 Likes
ok thats one part I forgot to mention - I need to round over both side of the piece so I will have to pry off, use a reversed gcode then put the piece back exactly in correct place. I have not done anything with taking a piece off and putting it back much less in reverse - it would be nice if there was some kind of concept in maslow to tell it where the point A and point B on a gcode for ex might be on the work space - I dont recall seeing something like this but ive been a bit absent from updates for a year.
Yoshi wrote:
ok thats one part I forgot to mention - I need to round over both side of the
piece so I will have to pry off, use a reversed gcode then put the piece back
exactly in correct place. I have not done anything with taking a piece off and
putting it back much less in reverse - it would be nice if there was some kind
of concept in maslow to tell it where the point A and point B on a gcode for
ex might be on the work space - I dont recall seeing something like this but
ive been a bit absent from updates for a year.
the normal CNC way to do this is to drill a couple holes and put pins in place,
then you flip it and know exactly where it is.
This is something to do in CAM, not in the maslow.
David Lang
1 Like
Another trick to deal with flipping your piece over is to set your job to work from center, instead of bottom left.
Jordan wrote:
Another trick to deal with flipping your piece over is to set your job to work
from center, instead of bottom left.
This requires that your workpiece be exactly centered so that when you flip it
you are still in the center. if your material is slightly wider/narrower than
you think, you won’t be centered.
David Lang
I haven’t done it on my M2, so I could be wrong. It’s one thing to have a reasonable theory, and quite another to have experienced it and can confirm whether it will work or not. I have done it on a gantry machine, and I can say that it does work on that platform.
Odd shapes add complexity, but a simple rectangle, draw a line from corner to corner on all four corners, and X marks the spot of center.
On these machines, it’s not necessarily about getting the workpiece back into the exact spot, but changing your work zero to the X and working from center. I am pretty confident that it would work.
Thanks that gives ideas to work with.