Maslow Mark II - 3D

Well done. This is the eloquent manifestation of what I was trying to convey with my “Nick Offerman” post.

So excited to see this!

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Fantastic! You mentioned boats, will you be making foil shaped rudders etc?

Would love to see a video and some more close-up pictures, great work!

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Thank you @USA1181 - yes my old sailing boat waiting for restoration, my daughter needs SUP and I will build second rowing boat for myself. I need time! So many projects…
…look at this Why I need Maslow - skiff and SUP
Cheers
Tomasz

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Thank you guys for kind words…
Watching cnc video is boring like watching paint to dry … ha ha ha … but if you insist ;-))
Sorry for raw video but I am not cameraman and I do not know how to edit clips ;-((



New challenge emerged: classical Maslow is forgiving for uneven worktop surface - sled just follow “peaks and valleys” and cut is relative to local depth. In my design Z distance is relative to gantry and flat worktop and parallel to gantry is a must - and that is the challenge ;-((
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Hi @TomD, do u have plans and material list for building it, I’m really interested in building one

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Hi Allan,
I do but not in the presentable form - a lot of hand drawings and notes; a lot of changes and experiments as usual with prototype. I have to reverse document “as build” without all “bugs”.

I do have gantry and carriage brackets models in Fusion360 f3d and stl format which I can share with you. I am in Poland so everything is design in metric. You should find steel profiles 40mmx40mmx2mm and 40x40x3 in your local steel stockist. If not then you have to redesign brackets and beams to inches and feet.

If I found time and generate plans I will post it in Community Garden - two pieces you already have Ring alignment and z-axis.

Ring and bit alignmentSimple pattern to align ring and router bit and reinforce ring mount

z-axis for AEG routerModification of AEG router

You can also find pictures of my old Maslow build to illustrate why I decided to build a metal frame - I need accuracy and precision and ease of material handling.

https://forums.maslowcnc.com/t/why-i-need-maslow-skiff-and-sup/6260/11?u=tomd

Cheers

Tomasz

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How well does it operate at the sides? It looks real smooth operating in the middle… :+1:

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No difference - when I cut test file (depth ~2mm) squares cutting goes as smooth as what you have on video.
There are no rotation of the sled and very little friction on bearings. My carriage/sled is quite heavy 5kg of lead and 3kg of router and ring so I have good tension on the chain. Everything is inclined 15deg so only fraction of weight pushes against rails (perpendicular to work space component) - rest hangs on chains and unfortunately - SPROCKETS. This is the weakest link - how long it will last.
With carriage/sled in the upper part of work space we have weight of carriage times tangent of angle between chains!!! Thats a big force for small bearings at the motors. It worries me.
The horizontal beams on which gantry hangs, takes only weights of the gantry; gantry is pushed towards workspace by perpendicular component of router/lead/ring weight and parallel component hangs on chain. We need that component to be reasonable strong to minimise chain sag, but we are paying prize by overloading sprockets bearings ;-((
The results of such force distribution is frictionless (well almost) X-Y movement but overload of motors.

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Wonder if you can make a sprocket block to spread the force on the bearings.
?

I know this might be a known concept.
Seeing that your frame creates a gantry of sorts,
Can that gantry have mounted the Maslow motor system and occupy that gantry area only to mill that area or sector?
Either manually or some simple force for a given time of operation have that gantry occupy an overlapping section to stitch the project over the 8 foot length?
Like a panorama photo stitch.
Wondered if this would improve the accuracy .

Thanks for the info I’ll try to build it

Allan
This may help - dimensions of the frame.
table Drawing iso v2.pdf (78.3 KB)
table Drawing top v3.pdf (96.8 KB)
table Drawing side v1.pdf (103.7 KB)
And additional more detailed pictures;
Start with even and level surface; clamp before drill ;-))


Adjustments of beam linearity; my local friendly mechanic welded nuts to the beams;

Lower carrying gantry beam can be adjust to be parallel to top beam

Adjustment of the frame so workspace is not warped (wheel at the bottom is just temporary help to lift frame by one person - not very good idea - discarded later). Later on I replaced 2x4 support with 40x40x2 steel profile.


2 x 4 (as a matter of fact 34mm x 70mm) adding stiffness to workspace

New and improved, high tech flatness measurements ;-))

Details of carriage

…and gantry.
The sequence of steps in construction is very important:

  1. set top beam level
  2. make bottom beam parallel
  3. Adjust hight of gantry to resulted distance between top and bottom beam
  4. Construct carriage and adjust width of gantry to result distance: use shims to minimize tolerance. I was able to be close to zero with negligible loose. If satisfied tight all screws.

    You should end up with ~40mm hight

    Have fun!
    Cheers
    Tomasz
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This is great. Love the effort to reach that hallowed precision. Good luck!

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Love your design. I literally just posted asking if a similar design that allows the sled to ride above the work surface would be feesable. From your video it looks like it is.

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I’ve just posted basic documentation Maslow-Mark-II-3D/ README.md
with upcoming updates.
Stay tuned
Tomasz

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This is looking awesome! I would say for people without a welder/friend with a welder I love insert nuts. It’s a pretty cheap option too!

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how wide is your top beam?

The areas I would be concerned about are the top and bottom, where force on the sled would tend to make the gantry rack.

in the bottom corners where force is the lowest, how well does it move to the outside edge compared to the sled riding on the surface? (more mass to move, but possibly less friction).

It would be wonderful if you could space out stock to the right thickness and run tests of the gantry vs a normal sled (all else being equal). How much of your accuracy is in the rigid frame, proper alignment of ring/chain/cg, and how much is the gantry arrangement (and if you want donations to buy you material for your testing, speak up, I’d be happy to contribute)

when doing a lot of cutting, does sawdust/chips on the bottom rail cause any grief?

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I think that test results (see above) and picture below addresses your concerns. I took this picture after cutting and putting sled into “resting” position. Part from lower bottom corner are cut as design +/-0.5mm - it is all what counts. About force distribution see my discussion with @madgrizzle above.
Dust is nonsense but fortunately material supporting angle bar at the bottom of workspace collects most of it - you must constantly clean it.


If I understand your question you asking for the width of gantry bar - gantry is 1644x432; see detail drawings in the Garden projects - Maslow MarkII-3D

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A question and a suggestion.

How much did the build cost you?

For uneven surface it seems you could mount a sensor to measure the distance and offset Z in Gcode. You may have to add more negative Z reach in this design. It seems like there should be a way to do this in realtime.

Anyone?

Thank you

Why wouldn’t you just let it touch down somewhere on the backboard and work with positive z-axis?