New Machine Build- rigid router 2000*1100mm

[bagherdn]

hi
i'm working on 2000*1100mm
my aims:
1- precision: using hiwin rails and ballscrews and using some nice diy methods
for building
2- high rigidity: truss structre design and build with steel tubes which are filled with epoxy granit
...
i'm working on it more thane 18 months!
it is very like to madvac cnc on this thread: http://www.oneoceankayaks.com/madvac/madvac_index.htm
but has many differences, belive me
here is a pic of milling main structure for x rails and a fault on rail installation
nowadays i'm working on gantry and installation of ballscrews.
anyone interested can post me , i'll be glad for sharing infos

[rbjem]

Definitely keep us posted on your progress. I am especially interested in the epoxy granite fill...

[giz]

Yes, more info on the fill would be great.

[bagherdn]

yes, here must be more info so:
i have seen many peoples makes diy cncs from steel, aluminum, wood and mdf and.. not for metal cutting, so i decided to build almost allpurpose machine.
the first problem to do that we need a strong structure (many big guys use cast iron) and for a diy it means $$$$$$$$$$$
so i decided to make it simpler and cheaper (using steel tubes like madvac cnc) and have benefits of epoxy granit, the problem may be here is differenc of Thermal expansion between steel (12 10-6/K) and epoxy granit (9-18 10-6/K) but they can be equal by changing formula of epoxy granit .
so i filled main tubes of structure and gantry

[bagherdn]

one my biggest problem for my projects has been money! especially for machining this big one
at first i wanted to use metal epoxy for creating accurate surface for rails ( it means using set screws on the structure to make rails straight in two directione with help of steel tight wire, and injecting metal epoxy between rail and body) but it was so difficult , if you straight rail in one direction and then in other, the first one will be change
so i paid $ for milling X rail position, but the resultant was Horrible ! -+0.2 mm
therefor i used hand scraping method and get it -+0.05mm

[bagherdn]

i've plenty of time & alittle $
so i made main body (with x rails) and gantry and then by installing a grinder i could do :
- making y rails position with accuracy copied of x rails
- nice cutting steel plates for future parts
- surface grinding steel plates
- ...
so i used it 4 iteslf

[bagherdn]

diy 3 axis stepper controller based on l297
out puts 4amp 12 volts

[bagherdn]

hi , slow progress but it is going on!
today i completed the x axis by installing ballscrew, I installed it as "one end fixed other end supported)

for this i used welding and epoxy binding. at first i installed temporary one end of ballscrew by screw
and installed the other end by help of gage to parallel with x rails and using lef-right set screws and two screw at under the end housing, then I welded first bearing housing (motor side)."pic start"

I pull gantry to nearest place to that housing and fix nut housing of ballscrew with epoxy (epoxy mix with iron powder that I collected from last part when I was grinding the y axis frame). "nut housing pic"
After becoming hard , Then I set the gantry at the end of machine (by turning the ballscrew) and put the other housing and fixed it with epoxy again. "end pic"
That was the process I used. More info on pics!

[bagherdn]

after being sure of installing ballscrew it was time to install the motor.
it is a 3.8v 4 amp unipolar step motor
for do that i used 4 steel bars as supporting legs and a mounting plate.
first i screwed the legs to the mounting plate (through the main structure) befor that i had put alittle place for setting the legs accuratly (be drilling bigger holes on the bearing housing) so it was able to set the four legs with an acceptable accuracy distance around the ballscrew axial then fix them with epoxy, then i installed the mounting plate again with bigger holdes than diameter of legs and with using a gage i set it with an accuracy about 0.08 mm radial and less than 1 degree in angular (by scrapping longer legs) and then fix it with epoxy ( what i would do if epoxy wasn't discovered or invented )
i used SRJ-40c coupling that needs radial accuracy 0.1 and angular 1 degree so not bad. i have forgatten to say that i used glass glow and alluminum sheet for sealing during casting epoxy resin .
result is in pics

[bagherdn]

todays i am working on big problem with my machine!
it's WORKING TABLE is so weak and isn't stable and damp enogh
it's deformation (at center) with a 10kgs load is about 0.2mm
so decided to change it (again) to a truss structure and in future feel it with EG
i'll post the result soon

[Apples]

Machine will deflect even more when you apply a cutttng force.