I’ve been using my stock XXL for about a year and a half now to make toy vehicles out of hardwood (maple and oak). Generally everything is 1” thick.
Currently when I cut a batch I’m running at about 75 IPM feed and doing 1/32” passes with ramping (45 IPM ramping). This seems to be a good balance of surface finish and speed, however sometime going into the hardwood even with ramping I end up losing steps, and I always have to sand the contours of the toys because ridges are created from the different step layers.
My question is, would upgrading to the Z-Plus or the HDZ give me a better surface finish and protect me from a loss of steps?
Ideally I would like to get rid of all of these little ridges that are created and save myself a bunch of time on the sanding.
Also the easy tram ability on the upgraded z axis seems like it would be an awesome feature!
Also are there any other factors I should consider that might help?
lost Z steps: yes, going for the Z-plus or HDZ will help, because of the screw mechanism. You should be able to mitigate the problem with a slow(er) plunge rate when using a standard Z though.
ridges:
if they are quite visible, this is probably a sign of sub-optimal tramming. The tramming plate on the Z-plus makes left/right tramming easy, but you still have to take care of front/back tramming (same effort for standard Z, Z-plus, or HDZ on that point). Learning how to tram the spindle is time well spent anyway.
regardless of the Z axis type, one strategy to get rid of ridges is to run a single finishing pass at full depth, after your normal contouring toolpath. You can typically use a slightly larger geometry for your regular contouring pass (using a small depth per pass, down to max depth), for example using an offset toolpath shifted outward by e.g. 0.5mm. Then, you can run a finishing contour pass using the original (non-offset) shape, and using a depth per pass = total depth. This will go all the way down, and shave off the remaining 0.5mm all around the piece in a single run, which should leave a nice finish (and no ridges).
I have had issues with different Z-axis heights on 3D machining (Actually, every 3D parallel toolpath I’ve used). I know my issue is not from losing steps, because as it continues on, they go away/come back. Here is a picture, since my explanation is confusing:
If you zoom in, you can see strips in the white parts where there are raised sections that went through multiple parallel paths before correcting. Is this a similar issue to yours?
I have thought that it may be my sending program, CNCjs, or maybe my z-axis somehow. I have recently purchased a HDZ, partly in hopes that it will fix this, and partly because it’s way more rigid for when I want to machine aluminum. If you could get a picture of your issue, that would help figure out what the issue could be a little better.
If you are indeed losing steps in the Z-axis, the HDZ will help for sure since it requires a lot less torque for the motor.
I started out with the belt Z and upgraded to the 3.2 HDZ. I love the HDZ and got it on sale for $400.00. Personally I have seen far too many posts about issues with the Z Plus. As of 30 seconds ago the HDZ was listed as $440.00 to $450.00 (depending on options) and the Z Plus $250.00. So the $180.00 difference would not be a deal breaker for me but everyone has their own budget. Since I have not had a Z Plus I cannot attest to the cut quality but I can say that the upgrade to the HDZ was great. The current HDZ is version 4.0 and has changed slightly from my 3.2 version. I also have the BitZero, BitSetter and the BitRunner and they make using my Shapeoko sooooo much better than before all of the upgrades. At a minimum I would recommend the BitSetter because it simplifies workflow. I am still using my Dewalt 611 router but I bought the 80MM spindle holder when I bought the HDZ to future proof my purchase.
