wow ! it seems like forever, but I finally got a couple of hours to start on the machine build.
I've made the bed in the form of a torsion box out of 1/2" MDF.
Finished bed size is 36" x 27" x 4" - max working area will be about 26" x 26"
I've laid the screw and rails on top roughly in the position they will be in, except it will be the bottom when finished.
The gantry will be torsion box sections too , and fixed to the rails under the bed for a clean look.
The bed will be raised on legs when I figure out how high they need to be !
so, it's been ages !
but the more I read, the more I feel I need to read !
anyhoo,, today I spent a couple of hours on my build.
the rails I lined up on a bit of 3/4 ply, using a new ground level as a straight edge.
I drilled through and counter bored underneath, before grinding off the bolts before tightening
I must say, the mixed sets of machine screws / washers / nuts etc . are one of the most usefull buys I ever bought !
I mounted the motor / screw assy on a bit of ply and shimmed it to be parallel
and this is them all layed out .
I now have to fix one to the bed and set the others in place of the 1st fixed bit.
I'm deciding whether to use the screw as the ref , or a rail .. but I don't suppose it matters much.
Holy crap, those rails are huge!
I was reading Millhead's build thread, in the early hours today (couldn't sleep)
one of the comments, I think by Ger, was "Paint it now - or it will never get painted"
this makes a lot of sense, so I've painted what I've made already, before I assemble it. If the machine works when it's done, then it might look a bit nicer too, and be more stable. If it is useless, then I've only spent a couple of hours painting !
It's drying right now, so pics tomorrow.
Hopefully tomorrow I can get the X screw and rails aligned / parallel / square and fixed, then start on the gantry
The other thing I did, was read through my / this thread from the start.... hmmm... I had to laugh at myself. it read just like every other newbie thread ! everyone want's to re-invent the wheel and not listen to what others have to say :blush: !
It's kind of embarrassing, but also a reminder to myself how much I didn't know back then. But hopefully how much I have learned along the way.
anyway ... more pics tomorrow, all being well
As I'll be building the gantry in the next few days, I would like some advice as to the working Z clearance.
I dont know exactly what I'll be using the machine for yet. I've never had a CNC before ! sheet and small carvings initially. PCB's also
X and Y working area will be around 26" each
so I need to start thinking about an "optimum" Z woking travel for maximum diversity, against maximum stability/accuracy .
As my rails are mounted under the bed, this will effectively make the gantry taller - and needs to be considered !
see ... I've been reading
So, I fixed the screw in the center line under the bed.
Then I fixed one end of each rail.
I then fixed a temp gantry to tie the 3 together, and ran the screw to the other end of the bed.
Then fixed the far en of the rails.
Then ran the gantry back a couple of inches at a time and fixed the rails as I went.
Quick phone vid of the X moving... remember , this is upside down at the mo.
CLICK IMAGE TO VIEW
I got it upto about 100IPM before it stalled, but I'm still running the drivers at minimum amps whilst testing. It's running at about 70IPM in the vid
Last edited by TrickyCNC; 02-10-2012 at 03:53 AM.
nothing impressive done
made a bracket from 1/4 plate for one of the bearings as I only had 3 out of 4.
Made the top and bottom gantry torsion boxes
Got to paint a dolls house tomorrow, so prob wont get much done here