Tantillus dimension question

What's the distance between the hole in the driving rod and the center of the rod running over it at 90 degrees?
I assume this is offset lets the line wind on and off nicely.

I had a ton of openbeam lying around, so I'm knocking up a Tantillus variant. My variant is direct drive, without couplers and I need to adjust the rod hole spacing, and it wasn't clear to me from the drawings what the critical dimensions are. I'll post pics and a link to the design when I get it running.

Thanks

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My blog [3dprinterhell.blogspot.com]

The outer rods are 162mm's apart and the holes are 166mm's apart making the difference 4mm's and then each offset would be 2mm's. If you have more space you could go wider but in the printed case that had to be pretty exact to avoid contacting the case or the X/Y end.

You do not need the holes if you are able to tension the cables correctly. I have one machine without any holes and none of the cable Z axis have holes.

Edited 1 time(s). Last edit at 05/03/2014 10:06PM by Sublime.

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Also have you looked at Goopyplastics variant or Ingentis or their cousin Eustathios as a starting point?

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Thanks, that's what I needed to know.

I started with GoopyPlastics design, but ended up redrawing the case from scratch for the 15mm open beam.

I have the steppers mounted directly to the case sides, I drilled out the drill rod ends, then drilled through and tapped the hole for a set screw, so the rod slides onto the stepper shaft. Not practical without a lathe, and it remains to be seen if the alignment is good enough, but it looks neat.

I have the case mostly assembled, but I'm blocked right now because I ran out of M3 hardware, but hopefully I can get some more progress done next weekend.

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My blog [3dprinterhell.blogspot.com]

Hold on I lied. I used the inside dimensions between the rods. The rods are actually 162mm apart center to center. That would make it only a 2mm offset.

I am editing the original post to reflect the correct dimensions as to not confuse anyone else.

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I figured I'd start without the holes and add them if they prove necessary, I ran 1000 or so 80mm circles without any obvious loss of position, so we'll see how it goes when I start printing.
Most of the major components are complete except the print bed.

Do you by any chance have the dimensions for the hole spacing on the two bed parts?
If not I'll pull them off the laser cut DXF's

I'll post a couple of pictures later, (my camera battery is currently dead).

Source files are here https://github.com/polygonhell/tslot-tantillus/tree/OpenBeam

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My blog [3dprinterhell.blogspot.com]

I don't actually know the bed hole spacing.

I think you will be fine without the holes in the rods, just be sure to re-tension the cables after a few hours of printing.

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And finally some pictures, mechanical parts work, need to put together the bed and do the wiring.
Obviously heavily influenced by GoopyPlastics work, in fact the git hub repo is forked directly from his and the open bean solution maintained in a branch.



Here you can see the flush Stepper mounts, the rod ends are drilled to 5mm, then cross drilled and tapped for an M3 grub screw to secure the steppers on the shaft. I had concerns on how critical alignment would be, but it's been a none issue in the tests I've run. Unfortunately not a very practical solution if you don't have a lathe.
This version uses a 608 bearing at both ends of the rod for support, even though the stepper shaft and it's bearings are probably sufficient.



Slightly better view of the ZAxis mounts, rather than use the original ZAxis with adapters, I've used an additional cross beam in the frame and mounted the Top and Bottom directly to them.

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My blog [3dprinterhell.blogspot.com]

Wow, that looks great!

That's pretty much what I wanted to do except to make the print area wider. I guess making things wider with that design would be pretty easy. I really like it has no gears, I don't care about the frankenstien motors sticking out.

So, can you get rid of the string next with a belt so it can tear down in 5 minutes? And a single stage belt on the Z would be awesome too.

It's relatively easy to make it laager, the issue is that if you go much bigger with 15mm extrusions, you have issues with tortional stiffness, using 20mm extrusions like the original goopy plastic design would probably let you get to 200x200.
The z axis would have to have a larger lever for a larger bed also.
Belts require messing with the X/Y bearing holders, I believer Sublime actually did a design for them, but I could be mistaken.

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My blog [3dprinterhell.blogspot.com]

Looking really good. I do really like the direct drive into the rods and if it had been easier to produce I would have gone that way in the first place. You can buy 8mm od x 5mm id hydraulic tubing that may work in the place of the drill rods but could suffer from being to flexible. Maybe putting a sold 5mm rod down the center would give it back its stiffness.

I only designed pulleys for belts to replace the gears. I have not designed any to replace the cables. But there are a few machines out there that have done just that. [translate.google.ca] and Ingentis has an option for belts based on Eustathios.

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Did you use nema17 40 or 42mm motors ? Thanks

Quote
Tibuck
Did you use nema17 40 or 42mm motors ? Thanks

I just used some steppers I had on hand, I'm fairly sure that it was these steppers I used
[download.lulzbot.com]

If not those it was probably a set of these
[ultimachine.com]

I'll check when I get home and verify which one but they are both more or less the same size.

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My blog [3dprinterhell.blogspot.com]