Hi,
any update? Did you finished machine? Run?
Hopefully this won't make you upset. But your Z-axis appears pretty thin. I think you are going to experience a significant amount of deflection. One suggestion is to replace that alum. plate (1/2 inch I guess) with steel flat bar, with at least one inch thickness. if weight is a concern perhaps Alum 7075 1 inch think would be a option. From the photos, I think you have about 2 inches of space between the Z-axis plate and the X-axis. You could also add square bar to the sides of the z-axis plate to increase rigidness (ie turn the plate into a channel. This would reduce deflection along the x-Axis direction of your z-axis.
Hi,
any update? Did you finished machine? Run?
http://www.fightech.blogspot.com
Not upset at all, i spend my time trying to post everything i do to get feedback, the more pepople that reads this, the easyer to notice errors and get new points of view.
As for the Z axis, i ordered a sheet steel bended structure that *shoud* reinforce the long plate, once i get it i'll se if it works or not. I first thought of making a thicker plate or adding reinforcements, hopefully, the part i ordered may work, if not, i'll have to replace the part for a thicker one!
Anyway, thanks for the advise!
P.S. It's alive!
http://www.youtube.com/watch?v=z1jdO3dDvGI]IMG 1559 - YouTube
P.S. 2 more parts made today!
Just a suggestion here regarding the reinforcing thicker and heavier isn't always the best solution how about using a bit of creative imagination and using maybe lighter material like aluminum sheet but with bends and or channels pressed into the sheet may also add enough stiffness without adding weight to the gantry........
Eoin
I agree that using a flat plate is clearly not the best option concerning weight optimizing. Though, adding mass is often a good thing to stabilize the machine. Now, it is best done while getting the maximal flexing stiffness out of the fixed quantity of material.
Cyril
Certainly agree, but if it works, it's a cost-effective solution. Plus, i had not enough time to think about a better solution, most shops in Spain are closed in august, and the ones that claimed to do more elaborated things, like punching, stamping etc would not accept orders until september. As i'll be leaving to canada the first week of september to study there, i'll have plenty of time there to figure out better solutions for the things i leave here!
I'm thinking of making the base frame in aluminium extrusions, it's not my favourite constructive method but regarding it's size, weight is an issue, and making an E/G structure would be quite heavy... Any ideas?
You can do it in aluminium extrusion, but I suggest you cast some epoxy granite as well to stiffen the structure as well as to dampen vibrations. Aluminium extrusion itself will make a poor frame, so unless you just want to use this as a router, better make it a bit stiffer ...
Sorry for the delay, i was in my mini summer holidays, i'm going to Montréal, fac de l' aménagement, i'm into industrial design, and i had the opportunity to get an international exchange
All the remaining parts arrived this week, been busy machining the ballscrews and reinforcing the Z axis.
More to come next week!
Hinge finished, still need to cut the square bar to length and make the frame for the monitor but the experiment works quite fine!
It has some PA spacers and metal rengs inside that creates enougs resistance to operate the whole thing and bea able to fold or move it when desired.
Hello,
Very good job!!!
Did you use some pigment in epoxy for the black color?
Can you give an idea for the price by kg for the epoxy Axson?
Many thanks
Hey man, i've got to admit I've missed this build thread, but never the less you are build a sturdy little bastard.
One thing that might make your Z to deflect in the Y-direction is the distance between your rail carriers. They are mounted very close and that makes it possible to "rotate" the Z before there's enough momentum built up in the carriers (The rotation isn't occurring in the center of a carrier, it's happening in the imaginary center of all carriers, which in the end transforms the rotational movement in the carrier to a linear movement - and linear movements are their purpose...). Imagine you're standing in front of your portal looking at the face plate connecting the Z and Y. When the Z is at its lowest position, push it sideways with your hand and you will probably see a "deflection" even though that is the strongest direction of the Z axis.
That's a classical problem on portals and the X-axis usually have this problem if it's driven by a single ball screw. But the X can be made super sturdy with the "moving knot" trick.
http://www.cnczone.com/forums/diy-cn...ock_solid.html
Usually you don't want the wires running at the Z-axis, it's better to widen the space between the carriers, specially in the height direction which will stop the rotational movement. Yes, you will loose Z travel unless you have long enough rails but it will be much more rigid with the wagons further apart.
Test it before you're stuck in too much rework, it's easy to fix now. Not so easy when you're done.
But said, very nice build so far.
thanks for the kind words, i've been, well, i'm really far from home and really want to come back and work in this... Anyway, the post you said, never thought about that, seems easyer to implement along larger axis but, i'll definitively give it a try!
Anyway, two months left to come back, baby get ready!
Very clean job, I like your work. Looking forward to the next chapter =)
How did it go?
Long time without updating, base casting on progress, updating soon!
Made the base support out of 50mm square steel tubing. Designed to hold all the electronics inside and some storage space.
Finally ordered the spindle, 0'75Kw Teknomotor, an old Lenze inverter from a broken machine we had lying around in the shop, and got almost all the electronic components.
Ordered a 20mm thick aluminium plate to machine the machine table.
I've been really out of the updating-this-thread thing but i'll try to keep posting.
Leix_99,
Great build, just read it today. Do you have anymore updates? I would like to know more about your Epoxy Granite recipe if possible.
Thank you,
Phil
Precision Machine Tool, LLC - www.mnprecision.com
Haas repair and CNC preventive maintenance MN, WI, ND & SD