Here's my latest project that I'm having problems with. I'm trying to engrave the backrest of a park bench. The boards are of course longer than the reach of my CNC. So I'm trying to mark where the reach ends, move that to my start mark and continue from there. (sounded good in my head) but it doesn't come out right. Any thoughts? Thanks.
If it’s any help, this 2mtr piece of teak was V-Carved in 3 sections. The layout was done in CAD / CAM then the toolpath was split into 3 sections each with it’s own origin (on the centreline) and each a known distance apart. The timber was pencil marked with each origin and the job completed as 3 separate parts. Obviously you have to take great care in re-positioning the timber straight against the fixed side stops but it all joined up perfectly. Tweakie.
No, but when I do the next one I will make a video of the setting up but I have no idea when that will be. Tweakie.
Thanks. I hope this helps other beginners as well. I've been playing around with the idea all morning. I found if the text fits between the reach of my gantry, I need to center the text not the board. (DUH) If the text doesn't fit then I'm stuck again. But sooner or later I'll figure it out. Keep the ideas coming.
One way that I have machined long parts is: 1: Make sure that the part you have to machine has a qualified straight edge on the long dimension. (Cut this!! ie. wood on table saw. IT MUST BE AS STRAIGHT AS POSSIBLE!!) 2: Make another part the same thickness as the one that you need to machine with a straight edge (see #1). This part is just for alignment and doesn't need to be anything special except for the straight edge. Clamp or screw this to your table and align it with the axis movement with a dial indicator (attached to the spindle) or put a drill or end mill in the spindle and use that to align at both ends of the alignment board. 3: Put the straight edges together on the table and clamp down your work part. 4: Before you machine your part program it to put a witness mark (a small scribed line) or ideally a hole that you have a pin the will fit at the joint between the two parts (half on each part). put this mark at your X zero Y zero location (this is the easiest can be most anywhere). Put another hole or mark past the area that you are machining, same as the first. 5: Do your machining. 6: Move your work part along the alignment part until the marks or holes line up. (a pin makes alignment more accurate) 7: Machine your second section. Leave your XY zero at the same location for both sections and use the second mark location in your software as the zero location for your second location. You can keep going forever this way. The longest I did was 24' part on a 3' table Bridgeport. If this isn't clear let me know and I will put make up a drawing showing what I mean. Dave
@GrandpawB It may be some time before I get around to making a video but here is an explanation of my earlier posting in picture form. Hope this helps. Tweakie.
After you cut the first work area just unclamp the part you are working on and slide it until the witness mark on the next work areas are aligned and reclamp.
This is going to be really unhelpful, because I have seen a Video on YouTube doing just this thing! No, I can't remember where! Sorry Gray
See! I knew I'd seen it somewhere. I just didn't know it was called that. I knew there had to be a name for that sort of thing. At least I can stop looking now, I was running out of titles to look for! Cheers Rick Gray
Thanks everyone for all your help. I found this on You Tube thanks to RICK2.0. Machining parts longer than your machine CNCnutz (Peter Passuello)
