dkj4linux
Elite member
Looks great! I really want to try doing some of those style of cuts at some point....
I finally got my drag knife on Friday and tried to do a bit of playing with my CNC over the weekend. But mostly had frustration...then caught some kind of food poisoning or flu and spent Saturday evening and Sunday feeling miserable
Friday I designed and printed a mount for my new drag knife. Took 5 revisions to get something usable...and I'm still not very happy with it. It's similar to the design allted shared but is designed to work with the hicwic quick change mount. Problem is there's no good way to print it without support which I'm not happy about. I could make it work as a two piece print but that bugs me too. What I have now is usable but not really nice enough I'm ready to share it yet.
Before the illness hit on Saturday I finally added a few threaded inserts to my CNC table so I can bolt stuff down. My plan was to bolt down my old 2'x2' base to use as a waste board, and machine a 12"x12" pocket in it to drop a mirror tile into which I would cut vinyl on. By machining the pocket I figured it would result in a flat surface that's even with the toolhead to make up for the fact that I still haven't got around to fully final leveling all four corners.
Well, that didn't go great. Thankfully I decided to test cut in some pink foam first. First cut came out almost twice as deep as I expected. It seems something is wrong with my Z axis and I'm getting almost double the depth I'm setting. So for second test cut I just halved my z but I need to look into just what's wrong there. Could be my z steps are wrong but I'm not sure how or why since I'm using the threaded rod/stepper drivers/settings specified by allted....just need to do some digging and see what's going on.
With my depth halved in estlcam I was able to make a nice cut in the foam and my mirror tile fits perfectly. I then put my dial indicator on (I made a quick change mount for it when I first built the machine) and found that there was still way more variation in high across the glass than I expected.) It's not horrible...about 15 thousands from the lowest to highest...but still not what I had been hoping for
I tried doing a few sample cuts on some vinyl with it but the vicious1 site was down so I couldn't find the suggested settings and then I started throwing up...so no further progress
I also still think there's something off about my machine since I expanded it. The center section just doesn't "look right" like it's not square anymore. Not sure if one or more of my pieces of conduit isn't straight or what. It was all really nice and square as a 2' machine and the printed parts haven't changed so I really suspect it's the new longer conduit pieces. But if I'm going to take it apart to replace those I want to do the new plastic parts too. So need to start printing I guess
It's fine for the needle cutter where z accuracy isn't a big deal....but for all the other things I want to do with the machine....I really need to figure out what's going on.
I hope you are feeling better now, Jason. I, too, am just getting over a week of illness (stomach bug and dehydration with a lot of flu-like symptoms)... laid me low starting on Thursday, week before Thanksgiving, and had it all that weekend and into early week. Finally went to the doctor (daughter thankfully "nagged" me into it...) on Monday and had improved enough to enjoy Thanksgiving with the kids. Thankfully they all came to me so I didn't have to traval.
Amazing the parallel universes we are running in... I, too, recently ordered and received a drag knife from Ryan but haven't done anything with it yet. Made a mount similar to Ryan's and adapted it for hicwic's quick-change mount... did it in two pieces, though, after the first -- with all the support -- didn't turn out worth a flip. I also have a large Donek drag knife that I got a couple of years ago but haven't done anything with yet.
I really think leveling your machine would be preferable to milling out a parallel suface... it's really not that difficult IMHO. I hate the noise of a dremel or router and frankly I never felt the MPCNC was rigid enough in the larger size to attempt such a thing. I've leveled mine with that simple little adjustable guage and it seems close enough for everything I've ever done... haven't put a dial indicator on it yet though.
I would highly recommend getting all those upgraded plastic parts printed and installed... it feels far more sturdy and square than my old one(s). My new 2'x2' laser machine has the upgraded parts and attached wooden base and sits on a thick piece of tempered glass... I plan to start playing with the drag knife on that machine when I get the time.
I've printed yet another set of Z-axis parts... SIL want's a camera slide to play with and I think the Z-axis and lead-screw assembly can be modified to get us something to play with. Using a 36" piece of 5/16" all-thread so should see about 30"-34" of travel when all is said and done.
Hope you get your machine straightened out and running right. I know I feel "lost" when one of my machines goes on the fritz... -- David
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