Looks like you get a pass for today’s round 
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This is looking awesome man! Keep it up!
You’re making me wish I had taken more time on the setup rather than rushing so that I could cut something!
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Thank you! If it hadn’t been cheaper to buy 200mm rails than to get the R22002 I would have ended up going that route. It has been a headache and I have almost picked up the R22002 a few times during this process while I was at Home Despot getting bolts and the angle iron to get this together. I think I will be very happy that I took the time to do this so that I have consistent Z depths. I already know that I will be switching to a 12’ top beam at some point, but I will make do with this for now. I think once I get it calibrated I will drill holes through the back with a 1" spacing and 1/4" holes like a peg board for holding my work in place. Thinking I will then make a clamping mechanism that goes into two holes for support and then pushes a piece of 3/4" ply like a vice jaw, with some dowels to keep it straight. basically like the brick bars, with dowels instead of bolts, and a bolt in the middle to push the jaw. I may be able to make them go into more than two holes, the more the better. I still need to model them up so I can print the hole locations on my laser engraver and buy the parts at HD. I probably won’t get much done until Sunday, but I will try to plug away at it and keep the updates coming.
EDIT: Latest STL/SVG files for the upright and carriage if any one wants to replicate my work.
Upright.stl (56.9 KB)
SpindleCarriage.stl (95.2 KB)
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Well, I got the sled mostly together today. I need to pick up bricks tomorrow while I’m out running errands as well as a power cord. It seems very sturdy and I’m pretty confident that the router bit is close to the center of the ring. I will have to write up some more tomorrow but right now I’m tired. PICTURES!
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I used a Dasani water bottle top as a dust chute for now. It isn’t pretty but I think it will get the job done.
This is the spindle all the way at the bottom of the travel. It smashes the bottle a tiny amount but not enough to affect anything.
This is the Maslow looking as if I could cut away with it. In reality I still need to calibrate it so I will let you know how that goes!
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Nice, I like the simplicity of the water bottle. Reminds me that we don’t always need something purpose built for the dust collection.
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Withhold judgement until we have seen how it works hahahah. I think it will work fairly well, but I don’t know. I try to keep things simple because simple tends to be more reliable in my experience. I once tried to hand an Afghani my $140 pocket knife to cut a water bottle to make a funnel. He laughed at me, crimped the side of the water bottle and smashed the crimp between two rocks splitting the plastic and allowing him to tear the bottom off. He then had his funnel and my $140 knife seemed a lot less necessary than it previously had hahahah.
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@MeticulousMaynard you wouldn’t have a quick link to the “setting up a Meticulous Z type Z axis for Dummies” would you? I’m trying to calibrate my machine but when it wants to raise to a safe spot it drops all the way down and makes the belt skip.
EDIT: I got it sorted out. It was really easy. I measured how far it was going with a dial indicator, divided what I got by what I asked for and then multiplied that by the original pitch. I got something like -24.25 IIRC, I will have to verify tomorrow.
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I got it to do the calibration cut and it isn’t returning to the same zero, is that normal? Tomorrow I will be adding the lower skirt of 3/4" ply and then I will attempt to cut the Maslow symbol out as my first cut. I used MDF for the back board and then I have a sheet of paneling over that as my waste board. I didn’t try the vacuum for the calibration so I can’t confirm whether my Poor Man’s Chute (PMC) is functional or not. Not sure if I had shown how I attached the PSU and the Z-axis motor but here is a better pic of that also.
I plan to cut the Maslow symbol and then I’m not sure what I will try after that. Maybe I will go for the Meticulous Z. Thanks for keeping up with me!
if it does not return to the center, you may have had your chains skip
David Lang
I don’t have anything of that sort really set up right now. I have some documentation on assembly in the Community Garden, but I don’t think it has any troubleshooting info in there. I’ll add it to the support to-do list.
The particular issue you mention sounds like the pitch needs to be set negative, although looking at your post again, it looks like you figured that out.
That’s exactly what I did, and it did a good job of getting me dialed in really quickly. I did notice some error, but I will be re-testing it before I get everything running fully. It’s possible that I just had an issue with my test setup.
FYI, from my measurements that I took during the test, I’ve derived 7.125 as being the mm/rev for the lead screw. To get your initial setting for Ground Control, you would multiply that by your gearing ratio. Then, as you mentioned, test it with the indicator to make sure that its working as intended. Multiply the error by your current setting to get the corrected one, if needed.
I’ll probably copy that last paragraph to the Garden page to make sure that it’s there for the next person. 
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You’ll want to swap that bungee chain tensioner setup out for constant weight based chain tensioners asap, The bungees don’t really work well in my experience.
Also, that vacuum hose is going to generate a lot of static electricity, potentially disrupting your z motor control and spindle psu, so it wouldn’t be a bad idea to run some 12-16 gauge bare wire inside the hose, having it poke out on both ends and be secured so that it can’t pull out. Connect the end near the vacuum to something grounded, and it should cut the potential for static buildup tremendously.
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Yeah, I thought that may be the issue, I think I’ll run through calibration again. I was hoping that it was just because I the calibration made it more accurately positioned on the workpiece. It looks fairly centered to my naked eye. I’ll see how much lower it is than the original spot it made a mark.
Well my math method seems fairly close with my gearing of 3:1 (60T on motor, 20T on lead screw) there’s a chance that the error is in my lead screw because I got .038” for indicated movement when I asked for 1mm, and I’m not sure close I’ll get to .03937” consistently when I know the lead screw has some play in it.
I have gone through and updated several of my posts after the fact to attempt to make this more useful for the next person. It’s been a really fun learning experiment but I’m not the greatest at documenting every step because I just want to dig in and see some results. Your “Meticulous Z Axis” thread really helped me get through this smoothly!
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Thank you! I was looking at the weight idea and I just haven’t decided the best method to do that at the moment. The easiest route seems like it would be to have the chains go over the top and have the excess hang down, then I just have to figure out what I’ll use for a weight. Maybe a soda can bottom with some concrete in it.
Is there a way to discharge the static without going the full hose length? Or will that still leave issues with the UPS and Z axis motor locations? I will have to dig through my stuff and see what I can find for bare wire. I’ve cut all of the insulation off that length of wire in a previous life and it isn’t fun.
That makes sense. That backlash may actually account for some of the error I was seeing last week as well.
I’ve updated the instructions in the Garden to include calibration for the lead screw. Hopefully that gets helps people get up and running faster. I realized while I was going through it that some of the information in there is outdated, so I will have to make some time soon to make those changes too.
And regarding the slack side of the chains, while I didn’t particularly like the bungees for the chain, I ran my machine with them for 2 years and it didn’t cause me too much grief. The big thing with hanging the chains down the side of the bed is that you have to make sure that the slack side is in line with the sprocket, or you’ll have chain skips from that side. There are a multitude of chain guides on the forums and in the Garden. I am in the process of switching over to counterweights myself, because, as @Jatt mentioned, they are better than the bungees.
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weighs can be very simple, see
running the chains over the top has the problem that gravity wants to make the
chains go straight down, which makes them not aligned with the sprockets (which
are 15 degrees from vertical), so you end up with chain skip problems. This is
one of the reasons the chain under setup was created.
David Lang
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Thanks for the input! I will pick up some materials on my way home today and switch to the weights. The bungee string wasn’t really working and the bungees I’m the picture were the quick and dirty way to replace them, I haven’t actually tried them and have little confidence they’d work very well. I have to add the lower skirt when I get home and either cast weights or find some to change the bungees.
milk jugs, water jugs (things that have a loop handle) work well. 2L soda
bottles need sand, not just water to have enough weight (you want about 4
pounds, but not a lot more)
David Lang
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I checked my Z axis pitch and I came to settle on -24.906 because I was just bouncing within .005" and not really getting anywhere. I want it to be more accurate but I settled on that being as accurate as it would be given my setup. I reran the calibration and this time the machine returned to the same center so I am satisfied that all went well. I still need to get the stuff to switch to hanging weight instead of the bungees but I will get to it. Tomorrow when I get home I am going to attempt cutting out the Maslow symbol from one of my scrap pieces of 3/4" ply. More updates to come!
I also added the skirt to the lower portion instead of the 2x4s poking out. And I during the test cut process the PMC performed well. I look forward to giving it a thorough testing tomorrow with the Maslow symbol!
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