Dr_Ju_ju

I was finding that the bed would 'droop' front to back and give some jerky movements. So I ordered another bed cross beam (as per the back one) and fitted it up with 3-way Delrin wheels etc. Stripped the whole lot down & made sure the bed framework ran true & 'clean' top to bottom, then with the motors re-connected & using Ooznest's anti-backlash nuts, I don't get the bed sinking unless I push down hard. 

check the cables\connectors\power, all issues usually boil down to one of those. 

Hi Kevin,

I'll post some pics later when I get home (there are some in another thread, but I can't find them at the mo), but the hole was 1.5 meters into the ground (2 meter duct).

I drilled some holes into the side and pushed some re-bar through to anchor it in place while I filled in, and around, the duct..

The reason for the additional duct was to ensure that there was no possibility of the OTA\weights etc. hitting the pier....

Hi Kevin,

I also used air-con ducting, the 280mm diameter you are using, together with some 150mm duct, placed centrally inside the larger & all filled with concrete.

Using a ground auger, I sank both tubes into the into the ground, leaving approx 700mm above ground, onto which I've then mounted control power supply, PC's etc...

I've managed to get the bed level, running on the v-rail smoothly, helped by the anti-backlash lead screw nuts (http://ooznest.co.uk/3D-Printer-Mechanical-Parts/Hardware/ACME-Anti-Backlash-Nut), but the proof of the pudding is yet to come..

I used to have a large Mendel variant but found it was too wobbly, and the D-Bot ticked all the right boxes for strength & rigidity, so I'm re-using the 300x300 bed, motors, Rumba control etc.

One thing I'm still not too sure on though, is the slope back to front of the bed & the reliance of the Z lead screws to keep things level (I'm using auto bed levelling, so I want it to start off level).

you only live once.....   I've used the Deep Purple on my D-Bot printer ....

I use E3D's version, they call edge http://e3d-online.com/Edge  Yes it is expensive, especially as the reels are smaller, but as you say, you get what you pay for... 

Try PetG, it has the strength of ABS but prints easily @ 80 bed with 240 hot end....

Just check that the cartridge will actually fit the hot-end, I've had some where the diameter was greater than the hole...

While at it, don't forget to make provision for a Pi3, hubs, cables etc.... 

Brilliant !!

I'm in the process of putting one of these together & I've found that the 'stock' 4 wheel Y & Z printed carriages, wouldn't allow correct alignment correct running etc. So I've tried the 2, 3-wheeled versions http://www.thingiverse.com/thing:1802733 & http://www.thingiverse.com/thing:1930200 (V2) & these work a treat....

Also a good source of some info is MavericCCIE's build on Openbuilds http://www.openbuilds.com/builds/d-bot-with-mods.4685/

have a look @ BeltingOnline, the 2.5mm, 177.5 mm, should be right one http://www.beltingonline.com/t2-5-synchroflex-timing-belts-2903

I've used it to cut 3mm acrylic & copper pcb's, not tried anything else yet, I use it in a well ventilated room, but not in a fume cabinet.

I think another Gina project coming on....

I bought one of these http://www.ebay.co.uk/itm/445nm-2-5W-2500mW-Blue-Laser-Module-With-Heatsink-For-DIY-Laser-Cutter-Engraver-/322497845897?hash=item4b165e9a89 then together with a Mostly Printed CNC machine (https://www.vicious1.com/assembly/ & http://www.thingiverse.com/thing:790533) but obviously any machine that can move X & Y (Z movement to achieve fine focus), can be used.

Control of the laser is done with the 'hot-end cooling fan' control, 10% to switch it on & 100% to cut...

Another thought.....

Add a Laser cutter to your big printer, then you can cut acrylic sheet, which could then be formed into a dome with welded edges....

One thought to reduce some of the hard work, would be to use a pre-formed dome e.g. http://www.ebay.co.uk/itm/Perspex-Acrylic-Dome-700mm-dia-/332184848462?hash=item4d57c2884e:g:NyYAAOSwx-9W1bt6 which could then be cut\modified\painted etc...

Good luck !!

My 2$ - one thing I've found with the bigger platforms is the limitations of the Ramps\Arduino controllers. I've used Smoothie Ware v2 board http://smoothieware.org/smoothieboard, yes its more expensive but gives better control. 

You could also try AstroBoot http://www.astroboot.co.uk/AstroBoot

Canon's usually run on 8.4 volts (all mine do) & I run them off a buck converter e.g. http://www.ebay.co.uk/itm/1-3-5-x-LM2596-DC-DC-Buck-Converter-Adjustable-Power-Supply-Step-Down-Module-UK-/161818793869?var=&hash=item25ad26d78d:m:mfnqbLbvaO6JOj7AXxfgPMQ with no issues..

for the 9v supply, get a bucky converter http://www.ebay.co.uk/itm/LM2596-DC-DC-Switching-Adjustable-Step-Down-Voltage-Regulator-Converter-3V-40V-/172058668488?var=&hash=item280f7eedc8:m:mDHLwFGVrh49Tb7BA-Y6CWg & run it from your 12v supply

Good Luck, if you have any problems (especially if you aren't used to programming Arduino's) just shout....

As stated elsewhere the most expensive part is the stepper, I use these http://www.ebay.co.uk/itm/27-1-Planetary-Gearbox-Nema-17-Stepper-Motor-1-68A-DIY-CNC-Robot-3D-Printer-/121683241474?hash=item1c54e2ea02, for approx £35, together with boxes\components\mounting parts etc. the complete package can be done for £50-£60.....

The Arduino on its own cannot drive anyform of motor, that's why the 'Arduino' part is usually made up from an Arduino Nano plus a motor driver module e.g. DRV8825, and some other components e.g. power connector etc...

 I mount mine in a custom 'black box' and can move it between various OTA's\Motors, so to answer your question, build the right one and you can re-deploy as required..