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Maslow Mark II - 3D

Need help!
I am making rudder for my sailing boat. In Fusion360 I’ve design NACA hydrofoil profile, cut in half (like two half’s of wing) and generated nc file consisting of four operations:
bore
face
adaptive clearing
parallel finishing
Bore and plane went quite well - Maslow behaved normal but when I loaded Adaptive (a lot of long cuts on different depth) and Parallel (finishing passes along profile) everything almost stoped. GroundControl reacted on clicks within several seconds. Sending commands does nothing.
My question is:
Is there limit in number of gcode lines which Maslow can process?
Is there some exotic Gcode commands which can make GC to halt?
Should I chop code into separate pieces and execute one after another?
System do not crush - seems like it slowed down to almost halt making cutting impossible.
here is my G code:
Any suggestions?pletwa1.nc (411.7 KB)

Just to illustrate what I am trying to do


Picture taken during “face” operation - to level stock.

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If this is the issue, my guess is that your gcode is made up of too many small segments and the limiting factor is the time it takes to send each segment over the serial connection to the machine.

Turning on buffering of gcode in the settings may help speed things up.

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Thank you @bar - I will try it tomorrow

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Thank yoou @bar very much - I have firmware and GC version 1.13. Cannot find in settings option for buffering. Where should I look for it?

Totally! This is the one you are looking for:

It’s the very last option.

Darn! My version 1.13 do not have this option! I double checked it. The last position is “Z-axis safe travel”
Should I upgrade to newest versions of firmware and GC? Will I loose calibration settings?

Thank you bar - I really apreciate your help

T

Ahhh gotcha! Yeah it was a later addition to solve exactly this problem.

You can update safely without loosing calibration. If you are worried about it make a backup copy of the .ini file where the calibration is stored.

Here’s where that file is for all the different OS:

Hi Tom, could you resend the technical drawings for the frame? I also want to use this setup for my Maslow.

Best regards!

Hi Max,
All drawings are here - look for files with table* in names

Cheers

https://github.com/MaslowCommunityGarden/Maslow-Mark-II-3D

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Gentleman,
Finally I’ve fixed problem with firmware and Ground Control versions, simplified design and separated all operations into different g-code files. Levelling my stock, cutting out contour and sculpting my NACA 63-012 profil are three distinct files. I used 8mm, flat end router bit and set around 13000rpms on my AEG router. The stock was 10mm and 4mm marine plywood laminated together to make 14mm block. Stock was fixed to workspace using wooden pegs. G-code was generated using Fusion360 under Manufacture -> 3D -> Parallel
This was my answer to coronavirus blues ;-))

It took about 3hrs to cut one half of the profile

I laminated two half’s and aluminum plate in between (for stiffness).

And here it is - primed and ready to be painted

Lesson learn:

  1. After gluing two half’s and aluminium plate the result thickness of profile is 1mm thiner than design. I did not recalibrate Z0 between runs and this is probably the reason to be off. CALIBRATE after every operation as Z-axis always have backlash - specially my adaptation for AEG router Z-Axis mod with AEG/Ridgid router . I was off by 0.5mm on both half’s and result was 1mm.
  2. My initial problem with Ground Control was with Fusion360 generating huge files. This was a result of my profile design. I tried to be sophisticated and included many complicated 3D transitions from one surface to another - like on the tip of my foil. Because I have flat end router bit, the software calculated very fine tool path - like many small spirals along surface edges. Sometimes the spiral had radius smaller than trackin capabilities of firmware. G-code had 800kB! No wonder that Ground Control did not cope with such code. I changed 3D design, direction of tool passes and my g-code dropped to 13kB!
    KISS theory (keep it simple… stupid)
  3. Maslow is slow but surprising precise! My rudder is 900mm long. Difference in hight in NACA 63-012 profile is as little as 0.1mm in some places. Take a close look - cuts are very precise, but you have to make sure that router bit approach each layer in consistent way. I force tool to retract to top and go down to new level before starting to travel and cut across stock. My z-axis is agonising slow so 3h cutting was mostly spend on z going up and down on both ends of my profile for every pass.
    Current design of Z axis is excellent for 2D job but we should rethink z-axis.
    I think that with current Z design I will not venture to projects like carved door panel or sculptures. For smooth profiles (like hydrofoils/aerofoils) Maslow is excellent!
    Keep yourself safe and healthy
    Cheers
    TomD
6 Likes

Beautiful work! Thanks for the update, this has been a really fun one to follow along with :grinning:

Hello Tom, first of all I would like to congratulate you for the fantastic machine you have built. Secondly I would like to ask you whether using a large lazy Susan for the sled ring would make things a little more smoother for you? I have seen this done by someone on you tube and the contraption seems to turn really easily. It runs on ball bearings ofcourse, I suppose that is much better then the existing pullies which I’m assuming movement can be a little ‘bumpy’ at times? Once again, well done and keep up the good work. Thank you

Thank you for your kind words.
Current ring design works fine and is very simple. I am not very comfortable with additional complications - I do not see how “lazy suzan” arrangement could improve accuracy or precision.

the lazy susan rings are not designed for radial loads.

David Lang

Thank you for your replies, both Ton and dlang. I have a few more questions for tom plse. I’m assuming that the carraige slides above the work piece but it does not brush against it like the original Maslow. That means that you have a gap between the bottom of the carriage and the work piece. How big is this gap? and can you control this depth or is it fixed? Sheet boards come in different thicknesses, if I’m not mistaken, 40mm is the thickest they come by. So have you set your machine to cater for the maximum thickness of sheet board? I think I read somewhere in this thread that you use 38mmm long cutters, however if you had to cut the maximum thickness of boards, you have 40mmm for the board, about 10mm gab between the sheet board and the carriage and the thicknes of the carriage. I assume that you would need to have quite a long cutter. Forgive me but I’m very new to this sort of thing and usually shy away from anything hi-tech but I have to admit that this is highly intriguing and I would love to copy your idea. One last question please; if for argument’s sake you replace the plywood board of the carriage with a metal one of similar thickness, then I suppose you won’t be needing the weight cans at the bottom of the carriage, no? In that free space I was thinking of using it for the z axis contraption, Maker Made are selling. What do you think? Thanks and well done. I just can’t find words good enough to congratulate you on the fantastic machine you’ve built.

Yes - you are right: the gap between workpiece and bottom of the carriage is 40mm. It is compromise between practicality, typical material and available router bits. There is a room to move work piece (sacrificial board) down by about additional 50mm (see design), but increasing working depth will create several problems:

  • cant use off the shelf router as Z movement on AEG/Bosh routers is about 40mm;
  • need 100mm long router bit;
  • during XY movement of carriage when cutting, the 100mm long router bit will generate almost 3 time larger side moment applied to carriage (opposite to direction of move). It will lift and twist carriage when cutting. To compensate it you will need much higher weight of carriage. It doesn’t make sense.
    Every machine has its own envelope of operation - do not go beyond it. Maslow is very happy compromise of many contradicting requirements and let’s keep it this way.

Hi Tom,

I have looked at your designs a few times now and am seriously thinking of copying what you have done. Pardon my ignorance but would it be a possibility to replace the carriage board with a piece of 10mm mild steel? It would weigh about 14 kgs and if I dispense with the lead weights I’d be getting close (but still a bit heavier) to the original. There are heaps of things I have no idea about going on here with the fantastic Maslow and just thought I’d ask.

Matt

Hi Matt,
Welcome in our community - congratulation for your decision to start this trip. It will be a lot of fun.
Your idea of heavy carriage looks promising… on the surface. By using symmetrical, heavy plate you are aligning centre of gravity with router bit, because you are getting rid of “bricks/lead cans”. It looks like desirable change but… When you are cutting material and carriage moves vertically upwards (I mean toward top bar), the rotating moment is applied to carriage. With the arm of router bit length and rotating axis along top wheels, the cutting force lifts lower carriage wheels. Positioning “bricks/cans” below router (shifting centre of gravity closer to lower wheels) helps to compensate this effect. It looks that with Maslow cutting speed and moderate depth (I never cutting more than 3 - 4mm of plywood in one pass) everything works fine. It is probably rough optimum - vacuum hose at the bottom also helps. (Keep in mind that chain is always attached below top wheels - rotating axis - and cutting in downward direction generates much smaller moment lifting top wheels. Try to draw force distribution and you will find why :wink:
My whole assembly weights around 12kg with router (for those stubborn Americans, British and Canadians who refuse to use civilised units it is 26 lbs and 7oz ha ha ha :wink: Bar suggest that sled should be around 30 lbs so your 15 kg (33 lbs) of plate plus router, plus ring quickly takes you on the heavy side. The small motors with gear may not last very long with such heavy load. Think about it.
I personally prefer plywood and if possible I will use minimum 15 to 20 mm (1/2" to 3/4") for stiffness.
Matt, never shy from asking - if you have idea the best method of verifying if you are right is first ask what other are thinking. Usually you will get answer: "Nooo you cannot do it, it will not work, stupid questions… " and so on. If you do not agree with answers - do it. Try and error is the most efficient method of discovery.
Good luck and keep in touch
Tom

Tom,

thanks for the detailed response and the encouragement. It gives me more to think about thanks. I think 'll stick with a proven way forward until i have significantly more experience using the unit. Thanks for the tips and the updates you keep posting on your journey, it has helped me a lot with understanding. Keep up the good work

Matt