Hi everyone
Well another nut joins the fray. Today I bought the steel I need to start my machine and starting this week I will start assembly. I figured I had better start a log now so that I can get the community to make sure I finish it! I am pretty good at the first 90% but always slack off near the end.
Anyway here goes.
The machine has the following specs / design features:
Gantry 3 axis plus rotary chuck on table
Configurable to become a 4 axis hot wire
3 table heights
Max working envelope 1.4m x 2.6m x 0.5m
Z drive - rotating ball nut 1:1 belt drive 16mm lead 450 oz/in stepper
X drive (across gantry) - direct driven 16mm lead ball screw 450 oz/in stepper
Y drives (2 independent) - 8:1 belt drive to stationary T5 belt each side in Omega drive config 450 oz/in steppers each side
Frame bolted steel 75mm sq tube and 150 x 75 I beam
Gantry 80mm sq 8020 aluminium extrusion (Item)
Bed / vacuum plenum - 8020 frame with 19mm forming plywood skins each side
Pneumatic counter balance on Z axis
Pneumatic raising and lowering of working bed (pinned in working config)
Epoxy grout used to level I beams prior to Y axis rails installed
Vibration mount feet on bed an fran used to rough level machine
Possibly fill frame legs with sand to increase dampening.
Current chop micro stepping drives
The design is intended to be open enough to allow the machine to be reconfigured to do jobs of varying needs ie.
in the high bed setup it is ideal for sheet work up to 150mm
Mid brings the bed mounted rotary chuck into line with the gantry for small detailed 4 axis work or thicker sheet work
Low position gives maximum working envelope and ability to spin columns up to 500mm in diameter
By being able to decouple the independent Y drives from the gantry this allows two new Z axis to be added to each Y and form a 4 axis hot wire machine with the maximum working envelope.
The design was also limited or built around existing parts that I was able to get for free from some decomissioned printing gear hear at work. the sad thing was I did not get everything and it all went to Simms metals and a crusher THK bearings, linear and rotary stages etc etc. The good news is I save enough to build one machine
So if you are looking at the design and woundering why I used big bits of billet aluminium here or that ball screw there the answer is that I had it.
So far it only really exists in CAD but hopefully I'll be able to post some real pics real soon. All comments suggestions or problems anyone sees please feel free to chime in.
Here's one idea that maybe someone can comment on:
As stated the frame is a bolted affair as I need to be able to dismantle the beast if I want to move it out of the garage and to a proper workshop if I get any work for it. Given my total lack of machining tools I intend to forgo all the nice pin arangements like on MadVac's machine and instead decided that the only critical part is the last surface the rails sit on. So heres the idea. Build the frame and level as best as possible with the vibration feet then form up the top of each of the I beams and have a connecting channel between them. Pour some very low viscosity epoxy grout into the formed area and let gravity and time to the rest. This hopefully will give me a perfectly level and coincident plane on each I beam onto which the 8020 extrusion and THK rails can sit.
BTW not all details are shown yet on the CAD drawings
Here goes nothing.... other than any spare time or cash I had :P
Cheers
Mark
BTW I live on the Central Coast of NSW any one else local?