Variant of Goopyplastic's Tantillus Variant (Ingentis)

Sublime Wrote:
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....
> If you are talking about it dropping when the
> power is turned off you could go to a worm drive.


Some brainstorming on that in his G+ post.

jimjimma Wrote:

Now there's an idea I hadn't come up with. I assume you're in Nz? Im in Welly. Where did you get these drill bits from? Like you rod straightening method too btw

I am in Auckland. I just got my metric tantillus fully assembled last night. The shaft straightening worked a treat. I just need my glass bed and some calibration and I will have my first 3D printer.

Ebay drill bits

I have been following this thread for a while now with great interest. I am in Auckland and currently have a working Prusa i3. I love the Tantillus design ideas. Have you started a real build yet or is this still theory? I liked the twin lifting belts and the rotating connecting shaft at he base.

I am about to make a Z stage almost exactly like you are talking about for a related but very different new design. However as I'm only looking just now at a 200x200 build area I'm going to simply have one motor with twin 8mm smooth rods all on the same single edge. I'm thinking of having the two vertical rails about 140mm to 180mm apart then printed parts from the rails to the middle of the far side of the hotbed to form the third support point. This will mean I have two corners and the far center as a three point adjustment for bed leveling. Not desided about screw, belt or cable to lift the Z platform yet.

Dave :-)

Robonz Wrote:
-------------------------------------------------------
> jimjimma Wrote:
>
> Now there's an idea I hadn't come up with. I
> assume you're in Nz? Im in Welly. Where did you
> get these drill bits from? Like you rod
> straightening method too btw
>
> I am in Auckland. I just got my metric tantillus
> fully assembled last night. The shaft
> straightening worked a treat. I just need my glass
> bed and some calibration and I will have my first
> 3D printer.
>
Good luck with the calibration process. Sublime's guide is very good so you stand a good chance of producing good prints straight off the bat
Thanks for the drill bit link!

acrux Wrote:
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Have you started a real
> build yet or is this still theory? I liked the
> twin lifting belts and the rotating connecting
> shaft at he base.
Yeah, there prototype is getting there - I've yet to actually print anything but not far off from that now (I hope_
Bunch of videos url=http://www.youtube.com/user/jimjimmmma/videos]here[/url]

>
> I am about to make a Z stage almost exactly like
> you are talking about for a related but very
> different new design. However as I'm only looking
> just now at a 200x200 build area I'm going to
> simply have one motor with twin 8mm smooth rods
> all on the same single edge. I'm thinking of
> having the two vertical rails about 140mm to 180mm
> apart then printed parts from the rails to the
> middle of the far side of the hotbed to form the
> third support point. This will mean I have two
> corners and the far center as a three point
> adjustment for bed leveling. Not decided about
> screw, belt or cable to lift the Z platform yet.
>
> Dave :-)
If you look back through my iterations of ideas for Z stages i posted earlier, I think you'll find something not too dis-similar. If you have your designs posted anywhere, I'd love to see them.

Oh, I should mention I've posted source files (full STEP model) and some of the STLs on youmagine.
It even got props from Erik (squeee)

Link

Thanks, I'm not using such a big hotbed so I think I can get away with a design like your earlier photos, thanks for that.

I am not quite ready to unleash this un-named monster on the world yet, so there are no online files to date. I may post a video of the first ever XY test tomorrow, I'll put a link here if I do that. I only had XY movement for the first time today. I am hoping, probably like you are, to give others a different direction in printer design to try out.

Years ago we had an amazing videotape robot at work that moved an XY picker unit that moved tapes from a series of postbox type locations to one of four tape machines. It used cables and pulleys with two huge stepper motors in one corner of the frame to drive it. The Ampex ACR225 is now long long gone as are the manuals but I have figured out how it worked and am trying to copy the cable design. It needs three 400mm linear bearings rails (not rods) and about 14 v-groove pulleys (at $10 for 20 pulleys on Aliexpress)! Time will tell :-)

Here is a very quick mockup of my idea for the z stage. It is in TinkerCAD, best seen using the Chrome browser. Internet explorer won't show you the 3D view

[tinkercad.com]

Got a video of the new monster, it's just moving the XY stage, thought you guys would enjoy it as it also uses cables. See if you can figure out how it works :-)

[www.youtube.com]

Dave

Nicely triangulated frame... It looks like one cable is used by the two steppers to control X/Y movement, with the second cable preventing skew of the moving beam. Nice. I don't really trust CoreXY to get that done.

Do you find that position is repeatable over extended periods without having the cable anchored to the spools?

acrux Wrote:
-------------------------------------------------------
> Got a video of the new monster, it's just moving
> the XY stage, thought you guys would enjoy it as
> it also uses cables. See if you can figure out how
> it works :-)
>
> [www.youtube.com]
>
> Dave

This is very nice Dave! Im a fan of linear rails anyway and is certainly looks like it's nicely balanced. Do you have a top down schematic showign the cable connections ala core x/y? How do you find the cable walking along the pulleys effects the tension for large movements?
I'd like to post this on the G+ communtiy if you're oK with that?

Actually it uses two seperate cables for X & Y so does not need the coreXY code at all. It has only been going one day and I don't know yet if the cables will slip. They seem to runn smoothly back and forward. I am having very minor binding issues but the moving single rail is still held to firmly by the printed parts at each end, they need to be able to move a little to stop the carridges jamming.

As for the cabling have a look at [tinkercad.com] (you will need google chrome browser) it shows how the cables go. It is very half finished sorry, so cables end in mid-air :-)

acrux Wrote:
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> Actually it uses two seperate cables for X & Y so
> does not need the coreXY code at all. It has only
> been going one day and I don't know yet if the
> cables will slip. They seem to runn smoothly back
> and forward. I am having very minor binding issues
> but the moving single rail is still held to firmly
> by the printed parts at each end, they need to be
> able to move a little to stop the carridges
> jamming.
>
> As for the cabling have a look at
> [tinkercad.com]-
> y-axis (you will need google chrome browser) it
> shows how the cables go. It is very half finished
> sorry, so cables end in mid-air :-)

OK, i"ve got my head around it - that's very clever. I assume the 'y' movement cable is fixed at the top of the linear rail on one side and the bottom of the rail on the other?

Acrux,

Just jumping on here to say how much I love that cable configuration.

I might use a lot of cable, and have a fair few idlers. But these things are cheap.

It gets rid of that racking problem of H-Bots (i'm pretty sure) as well as the kinematics, which is nice. Keeps both motors off carriage. It seems to be better than the UM arrangement due to the lack of rotating shafts that need bushings etc, which preclude you from using other linear motion systems. Like that lovely hiwin style rail you have on there.

I'd love to hear how you get on with this - I might have to build myself one of these, but using GT2 belting. Might look into getting some linear rails like those too. Any recommendation for sourcing those rails?

Stuck the video up on G+ and Sanjay Mortimer (of E3d fame) worked it out pretty quickly and say's he's now " a bit in love" with the idea.
Someone else posted this: pen plotter teardown that uses the same mechanism.

I didn't get at first that the two cables are for X and Y separately. I didn't take the time to carefully trace out where the cables ran. Plain as day, now.

The only thing I don't like about it is the fact that the Y axis has to move more mass than the X, and I don't think it can be made lighter than either axis of the Ultimaker arrangement. However, acrux's arrangement could much more easily access parked tools than Ultimaker, if you want to go with tool changes rather than carrying multiple tools on the carriage.

I look forward to hearing how those capstan pulleys work out. I would have gone right for a GT2 implementation for fear of slipping. Also, I can't help but think there might be something lighter than profile rail for the travelling beam, even though you can't beat it for simplicity of implementation.

Yes that's correct in that axis one end is connected above the moving linear rail and one below. I did think about doing a crossover at the far end but the pulley positions were a bit harder to sort out.

jimjimma Wrote:
> OK, i"ve got my head around it - that's very
> clever. I assume the 'y' movement cable is fixed
> at the top of the linear rail on one side and the
> bottom of the rail on the other?

Wow thanks yes the pen plotter is exactly what I am using. How do I see the comments on google+ ?

jimjimma Wrote:
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> Stuck the video up on G+ and Sanjay Mortimer (of
> E3d fame) worked it out pretty quickly and say's
> he's now " a bit in love" with the idea.
> Someone else posted this:
> [url=http://capolight.wordpress.com/2012/04/14/old
> -school-scientific-pen-plotter-teardown/]pen
> plotter[/url] teardown that uses the same
> mechanism.

[plus.google.com]

You may need to join the community first. Both Dale and I are active members, it's a little more graphical and less detail orientated than this forum but it's very well policed and the posting is generally pretty interesting.

My brain seems to have been integrating the last couple weeks during this morning's shower. It occurred to me that the pen plotter's Y axis (the travelling beam) would be a viable Z axis drive that wouldn't have required the shaft across the bottom of the machine. I imagine you already thought of that, but I wanted to record the idea here.

Thanks Dale, wow I had not thought of that, of course your right only six cheap pulleys and a single vertical say 8mm rod on each side of the bed. Motor can just mount to the base, anywhere. I think I will try it. I still need to design a tensioner for one side and a clamp for the other for the spectra cable. It could just as easily be a belt for the Z axis as well as there is lots of room.

Sort of like this but with round rods not linear rails perhaps?

Dale Dunn Wrote:
-------------------------------------------------------
> My brain seems to have been integrating the last
> couple weeks during this morning's shower. It
> occurred to me that the pen plotter's Y axis (the
> travelling beam) would be a viable Z axis drive
> that wouldn't have required the shaft across the
> bottom of the machine. I imagine you already
> thought of that, but I wanted to record the idea
> here.
Great Idea Dale. If I thought I could get the spectra tight enough I'd use it, but given the weigh of the beds when you get to 300x300mm - I think GT2 belt is a better option. This is definately going on my to-do list for the MK2.

I think that given the load is always positive and constant I don't think it would be an issue for using spectra. Of course the 100% guarantee of the belt with no slippage may be a deciding factor?

Well, this is awesome. Just drop an idea, and watch you all amplement it for me. Oh wait, I'm missing all the fun! I need to get started on my own build.

This is the guy I got my rails from in China not a bad price either $125US inc shipping took about two weeks I think from memory

Free Shipping Kossel Mini 3D Printer MGN12 12mm miniature linear rail slide 3pcs 400mm rail +3pcs MGN12H carriage for XYZ Axies
[www.aliexpress.com]

SanjayM Wrote:
-------------------------------------------------------
>
> rails like those too. Any recommendation for
> sourcing those rails?

Dale Dunn Wrote:
-------------------------------------------------------
> My brain seems to have been integrating the last
> couple weeks during this morning's shower. It
> occurred to me that the pen plotter's Y axis (the
> travelling beam) would be a viable Z axis drive
> that wouldn't have required the shaft across the
> bottom of the machine. I imagine you already
> thought of that, but I wanted to record the idea
> here.


Yet another thought on this. Some people aren't fans of the rotating rods in the Ultimaker arrangement. This pulley arrangement for travelling beams could be used for all 3 axes of the Ultimaker configuration. So, the X and Y steppers could be turned to have their shafts parallel to Z and brought somewhere inside the box without the external gears or belts. It also reduces the rotating mass, so higher acceleration may be possible. I think I like it, but the rigidity of the long cable or belt runs needs to be examined.

> Yet another thought on this. Some people aren't
> fans of the rotating rods in the Ultimaker
> arrangement. This pulley arrangement for
> travelling beams could be used for all 3 axes of
> the Ultimaker configuration. So, the X and Y
> steppers could be turned to have their shafts
> parallel to Z and brought somewhere inside the box
> without the external gears or belts. It also
> reduces the rotating mass, so higher acceleration
> may be possible. I think I like it, but the
> rigidity of the long cable or belt runs needs to
> be examined.
Hmm, good thinking. My only concern would be the number of contact points for the belt/braid. As Far as I can see, you need 6 pulleys, all of which will be under load because you need the belt/braid to be tight to avoid backlash and that might offset any gains you make from not having rotating rods. I don't really get people's opposition to the rotating rods, when you book at the quality of Ultimaker prints, it clearly works.

I'm not sure I understand your concern with the number of contact points. Do you mean that there will probably not be significant saving in rotating mass do to the number of bearings?

Jim how are you getting on with your Z stage? Because I didn't model the whole thing I'm having issues with solids where I need holes for cables to fit through. Never mind just a bit more wasted plastic :-)