Maslow Home Maslow Community Garden

My take on a Sled with No Bricks and Using a Spindle (Lots of Pictures)


#1

Firstly I would like to thank all the people on this forum for the immense amount of detailed information being discussed, without which I could never have designed and made this Sled, this post is some part of repaying all the help. I started designing things some weeks ago after getting an update from Maslow that the second batch of kits were nearing readiness :wink:.

I looked at routers available in the U.K. and like many did not find much which appealed. Somebody on the forums mentioned brushless spindles from China so I started to investigate these, there are many available from 500w to many kW’s for a surprisingly low price. At this point a thought about doing light routing with a Bosch Colt which can quit easily cut 6mm MDF in one pass with a 1/4" bit), but the Colt is only 600W so I decided to start out with a modest 500W spindle as I read that the Maslow works best on shallow cuts. I will now describe the Sled and give details of it’s construction. It was modeled in CAD before making (TurboCad).

Let’s start with some pictures (saves me a few thousand words?)



I have uploaded a copy of the Cad Model to Fusion 360 (I have only just started using it). http://a360.co/2z8kn7o

So the sled has a 10mm steel base plate (on 9mm ply), a top mount pantograph and a 500w Brushless spindle on a Z mount. The total weight is about 13Kg (28 Lbs) and it is 500mm in diameter.

Spindle and Z Mount


The spindle is this kit from BangGood
imagehttps://www.banggood.com/DC-48V-500W-ER11-Brushless-Spindle-Motor-Driver-Speed-Controller-For-CNC-Machine-p-1152289.html?p=96231686871952017014
The Z axis is made from this kit of parts
https://www.banggood.com/15pcs-400mm-CNC-Parts-Optical-Axis-Guide-Bearing-Housings-Aluminum-Rail-Shaft-Support-Screws-Set-p-1136854.html?p=96231686871952017014

The 12mm hardwood plywood parts were drilled using a template printed from CAD, which worked out accurately enough the whole thing worked 1st time. The rails and lead screw are cut down to about 200mm which gives a Z travel of 75mm. The standard Maslow Z motor drives the lead screw via a GT2 Timing belt, which is tensioned with a spring and roller. The whole axis is mounted to the base with metal angle brackets and M3 bolts. The lead screw has a 4 starts on a 2mm pitch so advances 8mm per rotation, this should speed up the Z movement.
As I havn’t got a Maslow kit yet the Z motor is not currently attached.
The complete Z axis and Spindle was about £130 [$175) (Including the 48v PSU).

Sled
Main body of sled is welded from 2 pieces of 180mm wide 10mm thick steel (bits I had in stock) into a T shape, which was then circularised with a plasma cutter. It was after I had cut it out that I finalised the pantograph design which need more room at the top so the Spindle has been mounted below the center of the circular steel. A piece of 9mm Hardwood ply was cut to 500mm circle (up from 450mm to accommodate the change of center), this is bolted to the steel with 3 M3 bolts. The ply has pockets cut to fit over the mounting hardware to give a smooth base.
The Spindle was mounted then used to drill a center hole. After the pantograph parts were drilled a 50mm hole was cut in the center with a 20mm wide channel leading down to a 25mm circle for dust extraction. There will be a acrylic disc with a 20mm hole in it covering the large hole to allow viewing of the cut. There is a 22mm right angle plumbing fitting to connect a short length of 25mm vacuum hose which will connect to the dust extractor.

Pantograph


I have been following the long thread on Sled modification with great interest and decided to use the top mount type on my sled. I have followed @dlang design idea but have added 2 extra arms which will stay straight with the chain but will provide a easy sled detachment point with the Hand knobs (and no fancy shaping needed for chain clearance). The parts are cut from 5mm mild steel (a bit crude as I only had 50mm strip on hand and had to slice it up) and I plan to paint them. The vertical linkages had the bottom hole drilled then they were bolted to the sled center hole and the other two holes drilled through all 3 parts.
They are mounted to the sled with a M8 connector nut bolted from below with a short M8 screw, then the arms bolted down from above with a M8 bolt and lock nut to set the pivot. The rest of the pivots are just cut down 40mm M8 bolts with lots of washers. the Hand knobs are M6 and the bolts will be fixed to the main arms.

Now I just have to wait for the Maslow kit to come (Has anybody from the 2 batch had theirs yet?). I have designed a electronics enclosure with all the parts including a Raspberry PI and Touch screen but that’s another post along with the frame design (pivoted from the ceiling).

I hope this post will help other people and please ask any questions, though it’s all theory until I get my kit…


Prototype for New Z-Axis
Throwing my hat in the sled modification ring
Router Recommendation (Australia)
Router and vacuum selection Australia simple answer
Servo to nema adapter plate
Best place for Variable frequency Drive Box for spindle
Possible Open-source Maslow Remote-view App and Computer Vision Alarm
#2

That looks good, you may want to put washers between the arms so that you don’t have larger surface areas of the arms rubbing against each other (which will also help preserve your paint)

how do you keep the knobs from working loose or being so tight that the stub arms have trouble rotating?


#3

I have two washers between the arms to separate them (also needed to use up the shoulder of the bolt).
It’s a good point about the knobs (I have not tried anything yet as I waiting for a kit), I think I will 3D print some knobs to fit a Nyloc nut…


#4

In fact maybe a bolt with a hole for a p clip would work with suitable washers.


#5

Your Z axis is great. I have been looking into a new solution as I have worn out two of the stock z parts with the Ridgid router. We may need to have a more permanent solution to the Z axis for precision and wear. The stock parts just aren’t designed to do the automatic work. Again nice job!!:+1: and thanks for sharing.


#6

@StephenMcG What a beautiful build! As far as I know you are the first to put a spindle like that on which is very cool. The faster z-axis is probably going to be a big plus also. I can’t wait to see it in action, which hopefully won’t be too long because kits are going out the door as fast as we can possibly pack them

@Blsteinhauer88 You have worn out your rigid routers adjustment mechanism TWICE!? And I thought I put a lot of miles on mine :grin: I’m impressed.


#7

Actually what is really bad is where the clamp end enters the recessed area of the motor? Is wearing, so, it slips off the clamp and the bungees: plunge the bit into the wood and ruins cuts and breaks bits. :face_with_symbols_over_mouth:


#8

Very nice! Nicely done on the linkages too! It looks pretty solid but if you ever find that there’s flex in your mounting bolts it would be super easy to add a spanner bar between the two mounting bolts. I like the microswitch Z stops!


#9

I had that problem, too. I tightened up the adjuster for how tight the body is clamped, and stretched the spring that presses that clamp end into the hole. :crossed_fingers: Fingers crossed, its holding.


#10

Thanks I will try that also @blurfl


#11

That’s well put. - :face_with_symbols_over_mouth: :face_with_symbols_over_mouth: :face_with_symbols_over_mouth:


#12

Nice idea for the Z-axis.

I have been trying to figure out what I want to do with my Z-xis and that looks like a reasonable solution. I considered using wheels on V-Slot extrusion, but I am concerned with the inevitable accumulation of sawdust during operation.


#13

Nice job.

I’ve been pondering what router to use as my Makita doesn’t lend itself well to z-axis integration. This is elegant and uses up a spare spindle I have, albeit a water cooled one which may be an issue with the large area of travel of the sled.

Off-the-shelf z-axis assemblies are available for ~US$50-70, including a NEMA stepper, but (again) will require a software mod to use steppers.

If you use an air-cooled spindle, they are likely to blow the v-slot clear of debris. In my experience of v-slot, dust isn’t as much of an issue as it might appear, especially if you have some sort of vacuum extraction for the tool head. I run a 3” paintbrush around the track between jobs and a vacuum at the end of the day. With the more-or-less downward-facing z-axis that will be even less of a problem. That being said, my “workshop” is open air, so dust magically disappears :slight_smile:


#14

@Zootalaws The Axis size is completely adjustable and can be made larger or smaller easily, the kit of parts has 400mm long bars and screw. I kept the travel short to maximise the stiffness of the 8mm guide rods, although I think the strain of cutting will be fairly low at Maslow speeds. If you download the CAD you can rearrange the linear bearing spacing for any size of Z mount. I think the Z travel will be enough as all the tools we are likely to use are short (<=50mm).
I was think of putting a duct around the motor to send the cooling air downwards. I will be using dust extraction as I am Indoors and if you work on MDF or Chipboard you get a lot of quite harmful dust.


#15

That looks awesome!!! I can’t wait to see it in action :slight_smile:


#16

FAB-tastic @StephenMcG !

Would it make sense to use HDPE for the sled’s bottom?
(IKEA cutting board for instance)

What is it that makes the dust harmful?
What’s the difference with plywood from a safety perspective?


#17

There’s a good discussion on dust collection and the kind of particles that will be floating around in the air here:


#18

plywood or real would tends to create chips, MDF tends to produce very fine
dust.

The dust has a lot more glue/chemicals in it.


#19

Re a plastic base, I gave just bought a 500mm square of 2mm thick UHMWPE (HDPE1000) for £20 which I will stick to the bottom. This will give a hardwearing skid plate which should reduce friction.

With the metal base, the center of gravity is low (about 25mm above base) so I should be able to use a shallow frame angle which will also reduce friction.


#20

Im so impressed @StephenMcG ! I just love the evolution of Maslow and the input from the great minds on this forum!!!