El Beast - Initial design phase, comments and critique welcomed!

[driftspin]

Magnus - not yet I'm afraid.

Thanks guys.

Got a chance to do the front plate today, and I am happy to present to you the (almost!) completed Z-Axis. If I'm being picky, just need to cut down the shaft on the main pulley flush with the top of the bearing and install a small cover... oh and I'm one M8 bolt short on the tramming plate (chair)

Was considering some etching on the front plate, but decided against it as I think it would end up too busy.

Also weighed it out of interest, and it comes in at 20.3kg minus spindle mount and spindle.

EDIT - some pics in slightly better lighting (but it's still a verrrry gloomy day!).

Oh WOW,

Art... thats what it is.

Grtz. Bert.

Verstuurd vanaf mijn SM-A320FL met Tapatalk

[AndyGuid]

Absolutely Awesome!

If that was mine I would almost be reluctant to use it and get it dirty!

[Zeeflyboy]

Hah thanks, hopefully it's art that works well too!

Wasn't entirely happy with my designs for the gantry and yesterday I sat down and had a bit of a play around with some ideas. This is where I've got to so far, and I'm pretty happy with the concept... just some finer details to nail down like grease port access.

The basic idea - main plate that mounts to the 200x40mm extrusion has been bumped up to 25mm while the rear plate will now just be a cover so overall material amount is similar. Staying with the original direct drive but with the extra width of the newer gantry this can be accommodated inside the frame by a cutout in the gantry arm and a small cover. The extrusion will have a couple of channels milled in to give clearance for a 30mm polypropylene webbing belt which will move with the sliding plate.

Looks complicated, but actually is fairly straight forward... think it'll be fun to have a play with.


So the overall gantry section




Rear extrusion removed and one belt gone so you can see the roller/guide mechanism




Top sealing strip removed




Belt/clasp detail

[jarjar]

I like your idea for protecting the motion bits. I may steal it for my own build :)

The gantry looks rather thin to me... And thus torsionally weak. I would go with a Misumi GFS8-100200, at a minimum.

[Voicecoil]

+1 - you just beat me to it Jarjar as I was calculating!
I've just done the sums on a piece of 25 x 200 plate and it's something like 17x weaker torsionally than a piece of the 200x100x5 box I'm planning on using for mine: adding the bit of extrusion on the back will help depending on how comprehensively they're bolted together, but it's unlikely to achieve the same rigidity as a decent box section. OK 100mm deep might be a bit much, but there's a 200 x 80 x 6 that's nearly as stiff. And with a box you could maybe run the returns of the slot covering strips back down inside it - at least that's what I'm planning .

[Zeeflyboy]

there's a 200 x 80 x 6 that's nearly as stiff.

At misumi? I can't seem to find a 200x80 anywhere.

[Voicecoil]

At misumi? I can't seem to find a 200x80 anywhere.

It's just a normal box section extrusion - these are my local stockists:

https://www.simmal.com/product/alumi...tangular-tube/

[Voicecoil]

If you want to stick with profiles, Item do a 80x200 that's not bad as far as profiles go:

http://catalog.item-central.ca/en/pr...-8-200x80.html

[Zeeflyboy]

I like your idea for protecting the motion bits. I may steal it for my own build :)

The gantry looks rather thin to me... And thus torsionally weak. I would go with a Misumi GFS8-100200, at a minimum.

Interesting. Just to be clear the part of the gantry that is actually doing the work is 65 x 200 mm made up of a heavy 40mm extrusion and a 25mm tooling plate, not just the 25mm tooling plate on it's own. The span is 620mm... it also has 6mm plate top and bottom which will be screwed down to the extrusion and the tooling plate. Given the relatively short span I don't think it should have much flex?


I could possibly re-work the design to use a 200x100 extrusion, but I think it would almost certainly require me to order new 25mm plates for the side arms as I'd need to take it further back at the top to accommodate some of the width. It is possible though as I need to order new extrusion anyway so I will have a play and see what I can come up with.

[Voicecoil]

Interesting. Just to be clear the part of the gantry that is actually doing the work is 65 x 200 mm made up of a heavy 40mm extrusion and a 25mm tooling plate, not just the 25mm tooling plate on it's own. The span is 620mm... it also has 6mm plate top and bottom which will be screwed down to the extrusion and the tooling plate. Given the relatively short span I don't think it should have much flex?

Yes, I got that, the extrusion will help, but I suspect it would need to be bolted to the plate at a lot of points to get it to work " as one": if they're not joined seriously rigidly, you won't get the full benefit of the extra thickness as they can slide over each other. If you want to stick with your current arrangement, I suspect that splitting your plate into 2 and having some in front and some behind the extrusion would also be of benefit.
OK your gantry isn't overly long, but if you're machining metal you need all the stiffness you can get. And as the rest of your machine is so beautifully made it would be a shame to compromise this surely?