Maslow Mark II - 3D

The gantry is already welded up as a rectangle which is a little hard to see in the photo, but I didnt represent this in the assembly yet in Fusion. The gantry, right now is 7’ X 2’, might be a little large but I can always cut and reweld if needed. I wanted the room to be able to have a sled/carriage that will adapt to either the router or a Festool track saw so it can be used as a CNC panel saw as well for efficient straight cuts.

I used 1/8" wall steel tubing which was an expensive overkill, but it is damn rigid if not anything else. I will mount some planed down 2x4x10’s across the width of the frame and then a 1/2" 5X10’ MDF spoil board on that. With the bracket design I should still have the ability to work with up to 1.5" thick material that is up to 5’x10’.

oh and the top image is actually the bottom bracket/guide that will run along the bottom tube of the frame. It has a depth adjustment that is an experiment right now which will hopefully enable me to dial in the gantry to be fairly accurately parallel to the spoil board.

thank you for posting your 3D files, I would love to get the source files from Fusion if possible so I can get the history which will make it easier to modify. For some reason when I brought it into Fusion none of the history came with.

I used the sled brackets that you designed with some modifications for the 1X1" tubing that I used for my gantry. Was pretty simple to shorten the bracket and move the guide bearing down a bit. I will let you know how it works out.

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Sorry Matt but I have quite a mess in my projects - some are with history, some without and parts are in several projects. I was learning Fusion when I was designing sled. Now I know much better how to have discipline in creating parts-components-bodies ( I even played with parametric design - what a pain )

Now I see - cool

Just a thought - You will have to mount motors quite far from frame plane. Think it through ;-))

I am hoping to put the motors close to the top and on the gantry itself rather than running the typical maslow triangle approach. I know this will fall out of the maslow family by technicality but was really inspired by this thread as i was building my plywood frame maslow to change my plans completely and build this cartesian style vertical cnc.

Ahh no worries at all. I have modified part of it already so am content with that. I was just hoping to have a full set of files for this project with history.

Here is the rolling gantry… need to work on sled/carriage next.

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Great stuff!!! Now I understand big holes in top brackets - to accommodate chain.
Hmm… thinking about forces during cutting… I am not quite comfortable with rigidity of the sled…. chain pulling along X at z= let say ±50mm in one direction and router bit resisting at z=0 in other… it will be a strong moment distorting whole assemble ( and rotating/lifting gantry/sled). I would consider cross braces at the top brackets; (or just piece of plywood to make a box). Just a thought….

Funny thing is that I’ve already collected step motors, controllers, Mach3 in anticipation of testing Maslow in cartesian configuration. I am interested in how accuracy, precision and speed will differ. Never had time to complete this task…

Good luck Matt and keep me posting

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Wow, that looks really nice. Great job! -Jeff

I havent had a chance to get in and build the sled for the gantry yet as I ended up having to fly overseas for work. Such is life.

I am working on a revision to the top bracket as well since it has been wanting to “walk” a little bit forward on the top beam as it rolls. I am thinking that I need to have either another bearing on the backside of the top beam or just a motion guide (kind of a hook) to prevent it from walking forward on the beam. I could also have an alignment problem but I will have to figure it out when I get back from Japan and have the new parts printed.

If anyone has any input on the design of this bracket or the larger frame itself, I am open to collaboration and incorporating new ideas.

My plan is to have the top motor mounted on the top right and have a chain loop that will handle the horizontal movement, the motor for the vertical movement of the sled on the gantry will be mounted to the gantry itself at the top left of the gantry. Z movement for depth will be handled at the router itself.

oh, i forgot to mention that I am also increasing the size of the opening for the bearings as I added Delrin covers/sleeves for those bearings. I am not sure if that is the right name, but it is far smoother than metal on metal.

Definitely I would consider bearing on the back side of the “hook”. It will eliminate potential of lifting gantry by torsion moment of chain/router bit.
You’ve mention that you want to drive X axis (horizontal one) by one chain at the top going down to the middle and back to centre of gantry - you need four sprockets and will add more resistance. I would consider two step motors for X axis: one at the top, one at the bottom. Gantry is quite long - I am not sure how stiff it is - PLA brackets are quite flexible. For a little higher cost you will have much better forces distribution. Motion controllers have standard double x port and Mach3 comes with option of driving two motors for the same axis. Additional benefit is better control of chain tension and clearance of workspace in case of adapting gantry to circular saw.

If you are going to change from the angled chains to a more conventional
movement, take a look at corexy.org. It keeps chains out from below the cutter,
and doesn’t have the same problem with racking that you will have with a chain
only on one end of the gantry. It also keeps both motors fixed, so you don’t
have to deal with wires to a moving motor.

David Lang

would you do the two steppers at opposite corners of the rectangular path? would i be better off using rack and pinion or ball screw rather than the chain?

I am looking at this now, seems to be a great approach, will dig in more to see if this will work at the large scale that I am building

Screw would be better - maybe, but cost! I have no clue how much would cost you 3m long precision screw. How to mount it - how to support it…suddenly you have engineering challenge. Naaaaa it probably will not work - chain will be my choice

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Here is the rack and pinion that I was looking at: http://www.cncrouterparts.com/gear-rack-52-p-193.html