Project Beaver

[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]

Have a doubt about the y axis being 45x90 profiles, even if used in L formation I think it might be to flimsy for fast alu cutting? Please correct me if wrong :)

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.

[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. .

[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.

[Boyan Silyavski]

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.

Before i was thinking exactly the same as Nrmadman, but remember once after your statement in another thread , i sat down and did the numbers looking at profile manufacturers data, and it seems you are right about the strength being enough and comparable with steel gantry.

[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.

[JAZZCNC]

Before i was thinking exactly the same as Nrmadman, but remember once after your statement in another thread , i sat down and did the numbers looking at profile manufacturers data, and it seems you are right about the strength being enough and comparable with steel gantry.

But that's the difference Boyan.? I Won't and Don't give advise on anything unless I have actual experience and know it works.
People need to realise that at DIY level the calculations mostly don't apply. Yes can't get away from pyhsics etc but most calculations are based on ridgid values and strict rules. They don't account for the DIY affects of muppets like US in working in sheds.

My thoughts on Calculations are don't waste the time,!! Instead invest the time looking for Real world examples and ask the person who made it what would do better.
The best Machines I've seen built have been built using just 3 Goods.?? . . . . . . . Good research, Good attention to detail and Good Old Common Sense.

[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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