Jeremy's ORD Bot Build

[JeremyBP]

That is the makerbot mk7 extruder. We'll see how fast it can extrude. Probably faster than a makergear, as it has no gearbox. We'll find out as soon as my thermocouple amps come in the mail. I also ordered 1kg of abs. That should be fun.

[IPvFletch]

For us noobs, is there a comparison chart somewhere of the extruders? My buddy told me he wants his to have the motor off the carriage to reduce weight.. and to make room for dualstruders.. And I don't know if I want a Plastruder, or an MK4 or an MK6 or MK7 or Wades or what!! I just want something good and cheap, cuz my wife is already having a heart attack over the cost of all this stuff..

[JeremyBP]

I don't know of any comparison chart, but here's a quick run down.
Anything called a plastruder or stepstruder is made by makerbot. The mk3-mk5 were all dc motor driven extruders, which really sucked. If you want to go with a makerbot extruder, get the mk7.
Then there's the makergear extruder. It was developed from some of the early printable dc extruders but wita stepper motor. It's got lots of torque and runs well. Makergear also makes hot-ends, which are of excellent quality.
The next category is the reprap extruders, which includes wade's and friends. These all have printed drives, and are the least expensive of all the extruders. You will need to buy a hot end for them though.
There are extruders that have the drive end mounted remotely, called bowden extruders. I have not used one, but the ultimaker does. Have a look on the reprap wiki for more on those.

Hope that's helpful.

[bdring]

That video looks great. 1000mm/sec using a NEMA 14 is pretty amazing.

The surface you have it sitting on did not look that stable, so I was worried that it might shake at 1000 mm/sec, but it looked solid.

I have printed about 40 things so far. On one high speed test, during the fill of a narrow section the ORD Bot started to move a little on my smooth oak dining room table, like a bristle bot. The print was not affected and the machine only moved about an inch. Another thing I noticed is that the ORD Bot is generally much quieter than most printers, but when on that same oak table it is a bit louder. I now generally run it sitting on a small hand cloth. It quiets down the table resonance.

When I ran it at PS1 or on my kitchen counter it was quieter than an ink jet or laser printer.

[bjoerngiesler]

I have printed about 40 things so far. On one high speed test, ...

You wouldn't happen to have more pics of your printed things? We want 3D printer pr0n

[jafenske]

That is the makerbot mk7 extruder. We'll see how fast it can extrude. Probably faster than a makergear, as it has no gearbox. We'll find out as soon as my thermocouple amps come in the mail. I also ordered 1kg of abs. That should be fun.

I'm assuming that most extruders have a gear box to apply more torque to the filament. The mk7 does not have gear box, so is that extra torque not required? Does that make the mk7 a less robust design albeit faster?

[JeremyBP]

I don't think that it is much of a disadvantage. Although the mk7 isn't geared, it is still pretty darn torquey. Also, 1.75mm filament doesn't need too much torque to drive.

[dzach]

One issue I have with getting the rest of the parts ready for the built is the length and type of cables needed for connecting with RAMPS. Are there any details available on these?

Documentation of the assembly comes out very nice. Only the problem with large files remains. I've taken the liberty and converted the large PNG originals to JPGs for the ORD Bot Assembly Preparation page. It now loads in a fraction of the time. The converted images and thumbs were uploaded to the wiki using the media manager.

[JeremyBP]

Thanks for fixing the issues with the wiki.
I happened to have some multi-conductor cable lying around for the motors, but I believe bdring used single stranded wires on his. I just ran the wires long and cut them at the end, so I don't have an exact length. If I had to guess, I'd say the longest is for the Z-axis on one side, and is probably 500mm long or so.

[dzach]

I guess what I'm asking would require disassembling a finished ORD Bot and measuring the actual lengths of all cables. Knowing the lengths may be useful for those who want to buy ready made RAMPS cables, complete with connectors. In that case, connectors at one end will obviously need to be installed after the free ends are passed through the extrusion holes.