Project Beaver

[JAZZCNC]

Your other point about y axis being flimsy, possibly true, but I only want to cut wood at speed. Should I change to steel? Any builds to look at?

No Not true it works fine and Steel is Completely OTT for your needs and don't let any Mad Man from Spain tell you different. .

[Nr1madman]

I think you can just upsize the profiles. Usual size for strong L gantry seems to be 2x 80x120 profiles. When I think about it that seems large, maybe I have misunderstood :D

[njhussey]

Looking good, my only comment is I think you'll regret it not being able to machine 1200 x 600 especially as you're nearly there. My machine can (just) do 1000 x 600 and I wish I could put 1/4 sheets of wood in to machine!

[OMLCNC]

Looking good, my only comment is I think you'll regret it not being able to machine 1200 x 600 especially as you're nearly there. My machine can (just) do 1000 x 600 and I wish I could put 1/4 sheets of wood in to machine!

Ok Neil, I can get the extra length in the workshop so I will change the design to use 1400mm HGR20 rails. I can see from the forum that some people rattle off a machine in a mouth and some people never get finished. It's a constant loop of reading, learning, redesigning etc, etc, but it only costs time. I'm finding it very useful to do a "Bill of Materials" as I go for costs and to make sure I haven't forgotten anything. I'll post it when I finish that and the next revision design.

[Boyan Silyavski]

Just the other day i was looking at my Z axis thinking" Good that i invested much time and money there, so no i dont need to move table up and down" ,not that i could lift 300kg table anyway. In other words i prefer very strong Z that could reach down and do the job without need of additional fiddling around.
When i was designing my machine i had the idea of using additional support to lift the material, but as i made it OTT, in fact i do not need anything additional.

So that is my advice.

[JAZZCNC]

Looking good, my only comment is I think you'll regret it not being able to machine 1200 x 600 especially as you're nearly there. My machine can (just) do 1000 x 600 and I wish I could put 1/4 sheets of wood in to machine!

Neil is Spot on. The little extra will make all the difference.

HOWEVER there are few things that need to be considered because that little extra length can give issues with Whip.
Use 20mm screws with BK Fixed bearings on each end for stabilty. Use 20mm pitch and apply 2:1 Ratio.
This will half the screw speed while still giving same speed as 10mm pitch. It will also double the torque and reduce the chances of stalled motors which is important when using slaved motors.

[Nr1madman]

Ok Your Wrong.!! . . . . Why would you say such thing without any experience of using this arrangement.?

I can tell you with absolute confidence, mostly because I came up with the design, and have tried and tested on dozens of machines that it easily handles aluminium in this arrangement.

:D
I did retract my statement, a bit at least!

[OMLCNC]

Thanks everyone for feedback and sugestions.

Latest design, incorperating longer bed so 1200 x 600 cutting area on bed, RM2020 x 1400mm with BK15 fixed bearings each end on X axis with belt pulley arrangement for one motor operation. More bracing added. Stil not decided on fix or movable bed yet.

Lots more to do to design, covers, cables, screws etc. But I have produced a bill of materials which I have started filling in.

I've done a sort of trafic light system so you can see were I'm short of advice and knowledge. I will search the forum for answers, but probably end up posting more questions here.

[Clive S]

Re your rails and screws might be a good idea to get a quote from https://aliexpress.com/store/314742 but go through him here :- Fred Lee bstlinear at gmail.com

Also re the screws when ordering quote the F length to be 30mm as the standard it is 25mm That is the bit where the pulley goes on.

[JoeHarris]

On the subject of detail and having just been working on this bit - I would change your gantry end plates a bit. I had almost that exact design at one stage but changed it to an end plate and a separate plate connecting the ballnut to the end plate (see my last post on my thread if your not sure what I mean). Lining everything up can seem easy in sketchup but as Dean says the DIY factor certainly strikes when your in the real world and you will want to be able to adjust things easily when you are trying to align the screw to the rail.


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