My first 700 x 500 x 300 Mill/Router machine

[kingcreaky]

Right... this is my first attempt at a useful response to somebody. I am reasonably new to this so please feel free to disregard my points I will not be offended.

To remove confusion, I have taken the liberty of marking the axis on your drawing...

Different people refer to the three different axis as different things, so ive done this for the purpose of my post, if my comprehension of the axis's is wrong it doesnt matter because it will work for the purposes of this post.

Ok, for a start ... weight... in my opinion dont worry about it... forget it... make it as heavy as you can. Only places you need to worry about weight is the carry weight of the gantry. not the bed of anything that doesnt move...even then you dont need to worry about it that much. Your initial post you say wood and possibly aluminium... you need to decide because this will greatly effect your design......

lets assume you want to do aluminum... or even deep into wood.. if you don't now, you will once its working. So think strength!... stuff cant flex, they use big words on here like 'resonance' and 'inertia'. essentially it has to be ROCK SOLID!. So make sure you use the materials you have in the best way to make making the most of them to achieve the most strength.

Firstly, you need to ensure your bed is VERY well supported throughout (not just in certain areas) so id suggest some cross bracing of some description underneath whatever material you decide to use as your bed. (ive drawn some in yellow). Id also probably triangulate the walls of the bed. so perhaps mount the entire bed frame on a flat metal plate. so plate on the deck build your bed frame on that and bolt it to the bed frame? although it could be said the bed material that goes on the top will do this for you anyway.

next thing id look at is that gantry... the runners on the x rails look far far to close together? Ive marked in blue.. look at pretty much any of the other legged lifted gantry designs on here or on youtube... all of them have the gantry 'legs' triangulated to spread those bearings apart a bit... otherwise imagine you are milling a straight line right the way through a work peace... the miller will go in the workpeace and you will then attempt to drag that entire gantry forward.. with the present design you will see flex in those gantry legs... in actual fact what you will see is judder.. it will move forward a bit.. the gantry will flex back. the gantry will spring forward and then move forward a bit again... unless you widen the part I have marked in blue (do you agree?)

I hear the other points in relation to the thickness of the material., but Id say thats in-significant compared to the narrowness of those gantry legs. and how close the x bearings are together.... tall people have longer feet....

Y looks pretty good for now.

Z looks a bit long... (or the beds too low!) again. imagine the straight line scenario I explained above. imagine you have triangulated those legs to remove the flex... next thing thats going to flex is that long Z plate.


read through every one of the build threads.. submit some more ideas. Im still learning but I thought id make my comments as I know how pleased I am when I get a reply on my build thread!

Finally, you have obviously already bought the TB6560. So dont worry about that too much for now. just concentrate on the design of your frame. In time as you learn more and more you may decide to replace it. for a slightly different setup due to vulnerabilities this gear has because of the fact its working to its absolute limit just running the steppers. but like I say dont worry about that too much for now.




try google sketchup.. aka 'trimble' free. there are loads of tutorials all over the web.. and it has a 3d warehouse.. where you can type in your bar like RM1610 or whatever and it will be there on the screen and perfect measurements...