I have not yet, I forgot about it actually. I should be able to get those numbers this weekend.
One quick question. Is this thread the most up-to-date and consolidated information regarding how to calibrate the Maslow?
Thanks,
There is definitely a mixture of threads that all contain calibration, accuracy, tolerances etc… I would say Ground Control’s calibration process is best information on how to actually calibrate the Maslow.
If you are looking to improve accuracy I would bounce in and out of
*Edit: I think the reason different threads on similar issues are created is because a thread is usually created to fix a certain persons issue. So others create their own thread to not detract from solving the OP’s original issue. Maybe a general How To dial in your Maslow wiki or thread should be started. IDK?
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Thanks for the info. I am a little intimidated by the distributed nature of the information. The fact that GC, its self, is the best source for information, is helpful. Probably the best bet is to update GC and start there. I have been a little hesitant to start calibration for many reasons, but the under-development nature of calibration is one.
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Yes, I was confused at first too. Start the Calibration in Ground Control and you will see what I mean. It walks you step by step through the calibration process. I’m not sure that it tells you that anywhere…?
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I have been trying to gather information about issues with the way the Maslow is cutting on the Troubleshooting Guide of the Maslow Wiki. If you spot holes, let me know.
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Hi All,
I’ve just gotten my machine built up and running. I’ve run into a similar issue as @Dustcloud, more error in vertical dimensions than horizontal so I’ve been reading through this thread and the others linked above. I see there was a lot of action on this a few months ago but it seems to have gone quiet since May.
Any new revelations since then? It sounds like trying to minimize error in ring/linkage mounting and checking chain tolerance are the two main things to investigate, right?
I haven’t done much troubleshooting yet, just the automated cal routine in ground control, but I thought I would check with you all before I dive in deeper.
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if you find your issue, let me know, i’ve got this issue as well… circles are wider than they are tall.
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I don’t have a running Maslow right now and can not help.
What I did when we still had fixed chain mounts, was to change setting numbers by +25% and -25% and see the difference. It does not only show in what direction to tweek, also giving an estimate on how much. If I was able to do testcuts for tweaking I would target:
- motor distance
- rotation radius
- height of motors over the sheet
19th April 2017
No guaranties that this is going to help. Just what I will do once my Maslow is back up.
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I am working on my machine right now, widening the top beam from 10’ to 12’. One of the problems I had with my previous build was that the left and right chains were not the same length, and although @bar worked on a routine that he hoped would create a software correction to compensate for this problem, the results were not successful. I decided to purchase one length of chain (50’ was what I found online) from which I could cut my sections, hoping that they will match in length since they came from the same batch. Since I am switching the chain, and longer chain is needed for the 12’ beam, this seemed like the time to do that mod as well.
I will report on my results, but it will probably be a couple of weeks, as End of Summer activities are encroaching.
Keep at it!
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OK, I have spent the last day resetting my machine with the new 12’ top beam (Finally)… Also did the following:
- Replaced the stock chains with 156" versions, cut from a single longer chain to minimize length variences.
- Replaced the 1/4" double flute router bit
- Cleaned and lubed all things related to the Z axis
- Upgraded to v 1.18 of firm and software, and wiped the EPPROM
- Raised the ring on the sled to match the motor deflection, 5.25"
- Added weigth (a piece of solid plastic lumber, total now 23.2 lbs) to the sled to adjust the “hang” angle to match the 15 degree workpiece slant.
- rebuilt the slack chain management due to the new top-beam
Went throught the cal routine… here are the basic values:
Motor Spacing: 3593.57 (Machine Measured)
Rotation Radius: 139.5
Chain Sag Correx 22.935121
Ran the Benchmark Test, and ended up with the following:
Then redid the Triangular Test Shape, getting the folowing:
Motor Spacing: 3593.57 (Machine Measured)
Rotation Radius: 140.5
Chain Sag Correx 29.363136
With the new Benchmark test:
Not exactly going in the right direction… any suggestions, team?
Thanks!!!
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There is a printout for that? I did all I could to measure from the ring to the base of the router which flexes! Basically it was an eyeball as well!
I don’t know what is happening behind the scenes when running the triangular calibration but, every time I ran it more than once without resetting the .ini, my accuracy was worse.
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Hey @ScrumdyBum! I did the 2nd pass based on your posts… how do you reset the .ini file?
Regarding my results, with my earlier frame and uneven chains, I was getting shorter verticals. Now they are longer. Am I correct that the machine thinks the chain is shorter than it really is? Being one prone to avoiding unnecessary activity, I did not physically measure the new chain, relying on the machine’s routine. So now, I am thinking I need to do a physical measurement of the chain to compare to the Maslow result, then do a correction in “settings” for the link size, and try get the machine measurement to match reality. Is this the path to follow, or is there a better (easier) way to solve the issue.
Thanks!
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I use the Windows Snippit tool to do a screen grab of the chart from the spreadsheet. Most of the data on that spreadsheet is Greek to me.
This chart is the printable centering tool?
I believe @madgrizzle posted that he had success doing that.
@bar was able to use the chain tolerance values to get the machine measurement to match tape measurement but I dont think that helped his accuracy.
The only way I have had success with accuracy was to use the sled with the center jig and to go through the calibration as is. I’m still off .05 in the Y.
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@Dustcloud I think you might be referring to this post
This was just an example. Not the actual process I used. I just added an edit to the post to explain. Sorry if that threw you off and caused more work.
I usually just delete the ini. When you launch ground control it will create another one. I always wipe the eeprom too. Not sure if that is necessary though. You can make a copy of the .ini if you want to revert back to it later.
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@Dustcloud I’ve spent 4 days trying to calibrate with a wider (11 1/2 foot) and have similar observations with the machine measured numbers. Can you please give me the difference between machine measurement and hand measurement for
- motor distance
- motor hight to sheet
- rotation radius?
I had no joy trying to override the wrong numbers during the calibration. I would like to compare your results with mine to see if there’s a tendancy.
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@Gero, here are the numbers you have requested after the above tests (yesterday)…
Maslow Motor Distance: 3593.57
My measurement this AM 3606.72
Motor Hight to sheet, measured 571.5
Rotation Radius, 140.5 Reported after 2nd triangular test shape
Regarding the rotational radius, My hand-built sled measures 119 from the spindle center to the outside of the ring. I do not know how it is calculated from there, but adding the space between the outside of the ring and the end of the chain the pin goes through, I get 14.287. Adding to the 119 = 133.287
Today I have done the following:
- Used the Maslow to measure both chains
Left, 3594.01 Right, 3594.63 (close enough to the same for me). I did this because my stock set did not match. - Since the Maslow thinks the chain is shorter than reality, an adjustment was made to the chain pitch in Advanced Settings. Real Measurement 3606.72 - Maslow Measurement 3594.01 = 12.71 / 3606.72 = .003524. 1.003524 x default chain pitch 6.35 = 6.37
Remeasured the Left Chain on the Maslow with this correction, and got 3605.92. Big improvement!
Using V 1.18 firm and software, performed calibration using the following:
Motor spacing distance: 3605.92
Motor to Workpiece offset: 571.5
Rotational Radius, maslow (default) 140
Chain Sag (default) 29.363136
Triangular configuration, Bottom Feed
After the Triangular Test, Maslow reported the following:
Motor spacing distance: 3605.92
Motor to Workpiece offset: 578.6
Rotational Radius, maslow 136
Chain Sag 42.649137
Running the Benchmark Calibration, here are my latest results:
Not too much to worry about on the horizontals, but the verticals could use a little help. What can I tweak to add a couple of mm to those long height measurements?
Thanks!
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