Here is my take on a metal maslow sled. Its 400mm round and the ring is 300 round (allowing for easily purchased routers in New Zealand) the sled is 8mm steel with a 4mm stainless skidplate tacked to the bottom. I’ll cut sets of holes in the top section to make it balanced correctly. The ring is 4mm stainless with 10mm steel stanchions at 12 4 and 8 o’clock. I will cut the bottom section of the ring off soon. My only problem possibly is weight, its going to end up around 20-22kgs with router and c beam z axis. Is this too heavy? Any advice/thoughts much appreciated.
Hi @SMcD, nice build, but …
Too heavy indeed. Check out this sheet https://docs.google.com/spreadsheets/d/1mv-sUyig7rTph58ell1ETJP32yo1pq4JgaVvp45PKqU/edit
My original sled with router and bricks was 15.9 kg = 35.0535 lbs and that was too heavy. I am with a spindle and a short aluminium c-beam now.
The height of the ring can’t be adjusted in order to balance the sled to have ~15° top tilted to the front.
You still have a chance to balance the sled by keeping additional weights (well not in this case) very flat, for example flat steel bars instead of high bricks and keeping the ‘Z-tower’ as flat as possible. Balancing also depends on how heavy and how high the router is.
Kind regards, Gero
Ok so weight wise I can fix that, I can cut most of the top/middle section of the 8mm steel plate away so should shed a good 5-6kgs inside the red section.
I’ve use the same 70mm height as my old maslow ring had, so should I try it first? If its no good then I can probably make them adjust up and down pretty easily.
alternatively you can just make your motor beam a lot higher. around 1.2m higher would work, but you need pretty tall ceilings then.
The reason our first laser cut base was 12" round& 3/8" thick about 12 lbs is so it could fit in a flat rate USPS shipping box
2nd version was made bigger 15" & 1/4" thick 13.5 lbs. so it could be compatible with ring and linkage arms. As a pleasant surprise UPS then came out with flat rate shipping for anything less than 50lb and less then 1 cubic foot.
The next base plates we get laser cut will stay around 15" but be thinner 1/8 and 6.5 lbs. so we can use galvanized steel plate (no painting needed) and the laser cutting is cheaper for thinner steel as well. We will put a 5-7 lb steel bar on the bottom to get the sled to around 26-28 lbs which is ideal for a 12’ and 2.5’ high motor beam.
Mentioned in case anyone else wants to make their own metal sled and understand that thicker is not necessarily better.
you can probabaly just use a drill hole saw and cut a few circles out to decrease weight as well.
Thanks for the info. I do have a really high ceiling in the workshop, but I’ll keep my current frame and do all the modifications to the sled I think. I should manage to shed the weight I think as the top section of the steel isn’t needed. Can you have too much weight on the bottom half of the sled? Or will that just make it less prone to rotation? I only ask as my z axis will mount on the bottom half so if I cut a bunch of holes at the top it will definitely be very bottom heavy. So anything above 25lbs or under 30lbs is about right? Thanks!
In the early days we had gears in the motors turning round. No idea how it is now. The main thing is the balance of the sled. You do not want the sled to tip either way at the top of the sheet, or at the bottom. You could end up with curvy lines where you expect them straight.
Ah ok so too much weight at the bottom might cause it to tip at the bottom of the sheet?
With a ‘frame’ around the sheet same thickness at the sheet you can avoid tipping to a certain extent. If you are running a ‘high weight’ sled, have a set of spare motors available, or at least the gears that wear out. The early motors came with a drop of grease, clear at the beginning, black later due to wear off. If you are solid on opening the motors and filling the chamber with some high quality stuff, do so. Otherwise target a sled that is in the low weight range. Mine, not as a recommendation, but for inspiration.
My last sled (till date, will make a better one):
Ok thanks for that, so I think have a plan now. I’ll remove the ring and cut away most of the 8mm base apart from whats required to mount the z axis and router this should halve the weight of the base. I’ll leave 30mm of the stanchions attached to the ring these will have 2 m6 threads tapped in them one above the other. And I’ll weld some 3mm slotted steel stanchions onto the base so the ring can be adjusted up and down. So hopefully I can get the base under 10kg with a really low centre of mass.
i dont’ remember any tests being done, but intuitively I think the lower the weight is on the sled, the better
I have killed 2 v1.1 original motor-shields and brought a 3rd one to give unpredictable results. I also might have killed a power supply, or it got buggy after a while. There is a reason why I am running a TLE5206 right now and with a power supply that provides 10A (over the top, yes), because I started with a heavy sled and debugging tried to send my sled to outer space and it was a destructive experience, including twisting my original motor mounts. A 500W (could be a bit more) spindle with a 1/8’ (3.175mm) bit and a sled reduced from 17 kg to 7.9 is a totally new world. Not at the end of my over 2 years journey, when it comes to the Maslow, the path is my my goal. The ultimate perfect solution is still to be found.
I’ve got the east bay source motor shield. I think its a little more resilient? I don’t remember the specs off the top of my head.
I can’t tell the specs of that one. If you continue with a heavy sled, look for the aluminium cooling ribs to be attached to the chips with adhesive thermal past/glue, like used for computer processors. The tape that came with the original kickstarter shields was a failure. I am more worried about your gears. My suggestion would be to go for weight tensioning of the slack chain. Avoiding a ‘backlash’ might save the gears.
Ok well these have the heat sinks attached to the chips which are vertical with a thru bolt holding them together. I could always remove them and put some arctic silver thermal compound on them and maybe even a pair of 50mm case fans? I have weight tensioning already with a set of rollers and some steel bars hanging at the back. This is the motor shield
This look like a TLE5206 shield. This will manage a heavy sled. Will the gears of the motors? What is the the Amp of your power supply?
Thanks thats some good news, I’ll have to check the power supply once I’m back from holiday in 4 days. Can I upgrade the motors to something more beefy? Or is it not really necessary?
No one has every upgraded to higher power motors.
Too many people seem to build the maslow machine around this default frame , when they should be building the maslow frame according to what they need. Maslow should really be a 4x4 ft machine IMHO
with a 4x4 machine, generally speaking you want a higher distance between the motors and plywood and also a heavier sled
minimum force is now more than 4x better in the corners then the default machine. And this is with a 30 lb sled that is often said to be too heavy. A 30 lb sled is only too heavy if paired with the wrong frame. We need to be more wholistic when stating what will work with the maslow and not be too ridgid in our thinking of a “default frame”
Thats interesting! Unfortunately I definitely need to cuta full sheet of plywood. However how does this look? I’ve lengthened the top beam as well as raised it. This now has a similar minimum and maximum force. I have tons of room to do this in my workshop. I would need longer chains however?
With regards to extra chain, is this the right stuff? https://johnbrooks.co.nz/chain-and-sprockets/roller-chain/14p-asa25-simplex-con-link?filter=918,910
#25 roller chain or ANSI #25 chain is what i could find on the specs.