@RIDVAN ARIK:
Nope, sorry, can't help you

 

Alright, now back on topic shall we?

 

At this moment, i have moved the machine to my (studio-)apartment to be able to use it a little more frequent. (yes i know, not ideal..)
I seem to have some troubles which i want to work out.
Mainly i've been cutting plywood from 6 to 12 mm thick, i experienced the following;

- Cutter leaves burn marks on the wood and will evenually "burn" / ruin itself.
I've tried to hold a power vac near the cutting area for cooling, that helps, but i need to slow down both the spindle speed as well as the XY speed a lot.

- Gantry seems not rigid enough.
After cutting some testpeaces of plywood on different feedrates (a simple straight line).
I found that the faster the feedrate, the more of a "curve" it makes in the first part of the straight line.
I'v "solved" that now cut down the feedrate drastically and more important, the cutting depth to only 2mm (with 4mm 2-flute)
Cutting takes forever now..

When twisting the gantry by hand, it feels very rigid, but there's a bit of flex when applying som edecent force.
Difficult to tell what is flexing though, my guess is that the Openbuilds gantry plates are too thin and are bending a bit.
I'm thinking of upgrading the machine a bit, hoping to cure this:

- Using double gantry plates
- Using double X-axis rail like on the OX

Any tips are welcome..

*Whisper* a 3d printer build is in preparation

 

Indeed, i did both. I don't know what my feedrate is right now, but it's awfully slow. Kress (1050-1) on number 4..
(and in this setting it works ok with a vac and a little patience..)
Could turn both up, but then i run into accuracy problems, so that's my biggest concern right now.

 

While i'm planning to build my own 3d-printer now (already ordered all the parts), i also will upgrade my CNC router a bit.
The biggest issue i have with it is (a little) flex of the gantry plate from left to right, and more flex due to the single 60x20 extrustion which is used for the x axis.
I will:
- Double the gantry plate and glue the two with epoxy to stiffen it up.
- Add another X axis 60x20 extrusion which the gantry rides on (just like with the ox)
Once this upgrade is done, pics will follow ofcourse ;-)

 

Thanks Gray!
I think adding extra extrusion in between will stiffen it up considerably,
but for the current gantry plates it's too bulky. Maybe on a next upgrade

 

Finally i made an rigidity upgrade to my CNC machine.
I found that it did flex a bit too much, the x axis beam was not rigid enough to my taste.
I now have doubled this beam, so 40x60mm instead of 20x60mm.
I glued two 20x60mm beams to eachother using 2 component epoxy resin.



It was crucial that top and bottom were absolutely flush ofcourse(!)
After that i extended the carriage and put 4 extra wheels.


(excentric nuts now at bottom, moved them to top later for better accessability)

I also doubled the Gantry plate which was flexing a bit when forcing the router up and down. (see picture above, right plate is double now)
These to upgrades help a lot making everything stiffer.
Hopefully i can route plywood a lot quicker or deeper now while keeping accuracy
(and start trying milling some aluminium..)

However, the flex i still notice seems to come from the wheels itself.
Even one wheel bearing has too much play i found out.
Guess replacing this bearing and upgrading the wheel to Xtreme solid wheels or even metal
wheels could solve this.. next upgrade? ;-)

 

Yes it does