Tomas's Kossel XL build log

I'm building a Kossel XL-sized printer. My current machine is a Kossel Mini, release 3 of T3P3's kit. I wanted something larger, so I'm taking a lot of hints from dc42's and DjDemonD's excellent builds. Here it is:



So... it's not much of a printer yet, but I've ordered most of the parts. I will update this thread with more pictures and notes as the build progresses, and I welcome comments and questions.

Nothing that special here. I glued ~315 mm long carbon fiber rods (6 mm OD, 4 mm ID) to Traxxas 5347 rod ends to form 350 mm arms. To assemble the rod ends, I did it the recommended way by placing the plastic parts in hot water and the metal parts in the freezer to exploit thermal expansion. I took dc42's advice and assembled 24 rod ends and chose the 12 with the least play. I modified an existing rod jig to fit rod ends with the center metal part already attached and glued everything together with 30 minute epoxy. I considered using thicker carbon fiber rods for increased stiffness, but the classic 6x4 mm ones were more readily available, so I went with that. We'll see how it goes, but I'm guessing it will be fine.

The aluminium plate is 3 mm thick with a 330 mm diameter and I ordered it from LaserMaster. They charged me £25.51 for the disc and £14.95 for shipping to Sweden. Their customer service is very friendly and helpful, so they're a good choice if you're within reasonable shipping distance. I will drill countersunk (3 mm?) holes into the plate for mounting purposes and use a 300 mm silicone heater to heat it.

For the frame, I went for the 2040 aluminium corners, which I hope will provide more stiffness than 2020. The extrusions are 355 mm long for the horizontals and 1000 mm for the verticals, which seemed pretty common. I chose black ones to match the corners. Two of the sides will use 2060 extrusions for the base and one side will use 2x 2020 extrusions to allow panel-mounting of various things between them.

Controller-wise, I will use a Duet Wifi, of course. They're not currently in stock, which conveniently stops me from spending too much money at once. For steppers, I have chosen to go for 0.9° ones for better precision. This, combined with the need for a relatively powerful bed heater, made me decide to use 24 V for the system.

Having heard good things about Mean Well, I chose their HLG-600H-24 "LED driver" power supply. It provides 600W, which should be plenty. I have a spare Bondtech QR that I will probably use for this project. At least until I get my Zesty Nimble. The world needs the Nimble, so if you haven't backed their Kickstarter campaign yet, do so now!

That's it for now. Rumor has it my RobotDigg package will arrive tomorrow, so I will soon have more things to show.

Sounds like you've everything in place, good luck and keep us posted it will be nice to follow along.

A question on the aluminium disc, do you intend to use it just as a heat spreader with a glass sheet on top of it acting as the build plate? Or do you intend to use the aluminium disc as the buildplate (with/without some sort of surface printbite/pei etc..)?
The only reason I ask is that 3mm is not very thick for the diameter in question and when heated, unless its cast aluminium (i.e. tooling plate), it might deform. With glass on top this is usually a relatively minor issue.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

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DjDemonD
Sounds like you've everything in place, good luck and keep us posted it will be nice to follow along.

A question on the aluminium disc, do you intend to use it just as a heat spreader with a glass sheet on top of it acting as the build plate? Or do you intend to use the aluminium disc as the buildplate (with/without some sort of surface printbite/pei etc..)?
The only reason I ask is that 3mm is not very thick for the diameter in question and when heated, unless its cast aluminium (i.e. tooling plate), it might deform. With glass on top this is usually a relatively minor issue.

Thank you!

Yes, I do plan to use glass sheets on top, so I hope deformation won't be a big problem. It's quite convenient to be able to easily switch between glass discs with different surfaces like PEI and BuildTak.
I ordered 4 of these discs (2 "lots" of 330 mm): [www.aliexpress.com]

The aluminium disc seems to be of an alloy called 5083 H111. The interwebs suggest poor machinability, but I think some simple drilling shouldn't be a problem, especially with 3 mm thickness.

Makes sense. I don't think you'll have any problems drilling it.

---

Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

The RobotDigg package did indeed arrive today. I've now got aluminium corners, the bed heater, effector, rail carriages, a bunch of fans, and some other stuff.



The bed heater seems nice. Now I have to figure out how to attach it to the aluminium plate. I can get a 300x300 mm 300LSE transfer tape from a local reseller. I've used that for attaching PEI to glass, so that might work.



For anyone wondering, the 2040 aluminium corners from RobotDigg do include idlers and bearings for the top parts, which is a relief. The idler seems to differ slightly from the one included with my previous 2020 corners; it's symmetrical, so the belt part ends up in the middle (with 9 mm on each side of it). The 2020 version is longer on one side, as seen here:



I also ordered some "clip clap" 2-pin connectors. They're so cheap, I ordered 16 of them. Or so I thought – the price was apparently for 10. So I am now officially the king of clip-clap connectors with a big bag of 160 pieces:



Edited 1 time(s). Last edit at 11/02/2016 01:11PM by tomasf.

If the 300 LSE is either 468 or the better 8153 variants then that is fine to attach the heater. I would check what current that heater needs mind and make sure you are within the Spec of the Mosfets on your electronics board. It will draw approx 12.5 amps at 24 Volts

A lot of people when going to that size of bed tend to opt for a AC heater and SSR.

Doug

Quote
dougal1957
If the 300 LSE is either 468 or the better 8153 variants then that is fine to attach the heater. I would check what current that heater needs mind and make sure you are within the Spec of the Mosfets on your electronics board. It will draw approx 12.5 amps at 24 Volts
A lot of people when going to that size of bed tend to opt for a AC heater and SSR.

Hmm. I'm not sure what kind it is. I will email the reseller and ask. Thanks!

Yeah, Duet Wifi can handle 15A for the bed heater. Until Wifi is in stock, I will use an older Duet 0.8.5 board I already have for prototyping, but it won't have the capacity to drive the bed.
I did consider powering the bed with AC, but I don't feel entirely comfortable dealing with mains voltage like that. I bet I'd end up dying. That would be typical.

Tomas

The advantage you have with a delta is that the Bed never moves therefore you don't stress the wires at all and as long as you use a Good RCD within your mains supply you should be perfectly safe However it is good practice to make sure all metal parts are earthed as well.

Not sure what the Heater Capacity is on the 0.8.5 but even at 15 for the Wifi I don't think I would want to push it that far (I never have on my 2 or the previous 0.6's I have used that's not to say that it won't cope David or Tony are much better placed than me to comment on that.

Also My heated bed is 350 Watts at 300 Diam and to be honest think it could do with being a little higher more towards 450-500W so that would def be out for a 24V Heater.

I have just had My heater for the Big Delta I am building arrive and it is 1500W and I think that is right on the edge at 0.5 W/CM^3

Edited 1 time(s). Last edit at 11/02/2016 04:36PM by dougal1957.

Tomas, the Duet 0.8.5 should be OK at 15A bed current if you add a wire on the back of the board. See [duet3d.com].

The Duet WiFi should be available again in Europe very soon because new production is in progress. I think Filastruder in the US still has a few.

Edited 1 time(s). Last edit at 11/02/2016 04:41PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Think we croosed over at same time David??

Received packages today containing extrusions and stepper motors. Had to pay 505 SEK ($56) import duty for the extrusions, which is close to the full price of the extrusions ($60). Oh well.

The power supply is finally on its way. After two weeks of silence from Conrad, where I ordered it, I got a message telling me they couldn't get hold of any from their supplier, so I had to order it from another (more expensive) source.

Anyway, I assembled the frame, and it looks pretty good!



The motors look good from what I can tell, but I haven't hooked them up to anything yet.


I mounted LED strips in the slots of the top horizontals and attached some transparent printed covers. Turned out well, I think.

Over the weekend, I let my father drill three countersunk 3 mm holes into the aluminium bed. Turned out great.



It turned out one of the RobotDigg carriages had a faulty thread. It won't catch onto the screw, so I requested a replacement.

I have mounted the Duet and hooked it up to Ethernet, motors and the bed heater (with the positive heater lead connected to the power supply to overcome 0.8.5's bed current limitation). Everything seems to work great so far. I was a bit concerned about the bed heater cables. They look a bit on the thin side to be carrying 12 amps, but it seems to work and nothing has gone up in flames yet. My IR thermometer says the cables are around 30-35°C, so I guess that could be worse.

Tomasf,

Did you purchase your extrusions from Robotdigg also? Do you recommend them? I was thinking of building a Delta and yours look wonderful so far!

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BuildAThing
Tomasf,
Did you purchase your extrusions from Robotdigg also? Do you recommend them? I was thinking of building a Delta and yours look wonderful so far!

Thank you! No, I ordered the extrusions from Xinlong through AliExpress, because RobotDigg don't have 2060 ones (if I remember correctly). They arrived extremely well packaged, and seem to be of good quality.

Actually I think he meant the Extruded Corner and if so I have built 4 Deltas with them now and they are Very Good indeed. I have been using a set for well over a year now and they are still going strong.

Doug

Thanks guys! Actually I wanted to buy both the corners, and the linear extrusions. I am still looking for information about the quality of the Robotdigg linear extrusions.

I may try AliExpress, thanks for the link tomasf!


Mark

By linear extrusions do you mean the Tee/Vee Slot extrusion or the Linear Slide Rails also where in the world are you there may be some other recommendations for you. I have built one printer that did in fact use the Robotdigg Tee Slot extrusions and they were absolutely fine. but there maybe be something better depending on whether you want to use Linear Rails or Rollers?

HTH

Doug

For extrusion my advice is order from the closest to you, local is the best even if they cost a little more. The less time they spend in the mail the better... unless they ship them in a hard cylinder package, postal service will not care about throwing them around and the result can be bend extrusion. Remember for delta your 3 long rail must be perfect and the longer the extrusion the easier to be bend by bad packaging.

I order mine from 2 hour drive from me and some get bend a little (1.5 meter and they tape a bunch of screw I order at the end meaning the extrusion never sit flat), next time im gonna take a road trip and get them in person or specify they use a hard cylinder packaging.

Thanks again! Im in the US, specifically near St. Louis. My initial plan is to use rollers.

Ok in that case you want to get your Extrusions from OpenBuilds and use there Wheels it is proper V-Slot and the wheels/rollers work perfectly in them they also go up to 20x80 in size.

Openbuilds

There gantry plates along with the V-Wheel kits work extremly well you will need 1 excentric spacer per carriage if you use 3 wheels but you can use printed carriage parts as well.

But do get the Robotdigg corners and maybe the carriages/effector depending on which way you intend to go.

You could also check out Ultibots who I think Stock the Robotdigg corners in the US along with Hadyn Huntleys very good Mag ball arms and balls along with matching effectors and carriages.

HTH

Doug

Awesome! Thanks Doug!

Yesterday, I attached the heater pad to the aluminium disc using the 300LSE tape. I still don't know if the tape is rated for these kinds of temperatures, but it has worked perfectly for attaching PEI sheets to glass. It seems to work so far, and the bed heats to 65°C in 2 minutes.



I also received a 300x300 PEI sheet, which I have painted black (to make it work with IR sensors). Still waiting for the glass discs.



Today, I received the DyzEND-X hotend. It's really tiny. I didn't read the specification carefully enough, and somehow assumed the top thread (for mounting a push-fit bowden tube connector) was 1/8" BSPT like my previous hotend, but it's apparently M8. I wish they would just include a connector in the package, but now I have to buy one, ugh. I'd appreciate suggestions for sellers of these M8 push-fit connectors within the EU.

I've used the 300lse adhesive to attach printbite to an aluminium build plate seemed to work just fine even long term. Better than I can say for my Shenzen Ali Brother silicone heater which was advertised as having 3M adhesive but came with a Chinese brand adhesive which is peeling off in the centre. Maybe I can remove this stuff and apply some 300lse which I have spare.

---

Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Quote
tomasf
Yesterday, I attached the heater pad to the aluminium disc using the 300LSE tape. I still don't know if the tape is rated for these kinds of temperatures, but it has worked perfectly for attaching PEI sheets to glass. It seems to work so far, and the bed heats to 65°C in 2 minutes.

[attachment 86037 IMG_0546.jpg][attachment 86038 IMG_0549.jpg]

I also received a 300x300 PEI sheet, which I have painted black (to make it work with IR sensors). Still waiting for the glass discs.

[attachment 86039 IMG_0552.jpg]

Today, I received the DyzEND-X hotend. It's really tiny. I didn't read the specification carefully enough, and somehow assumed the top thread (for mounting a push-fit bowden tube connector) was 1/8" BSPT like my previous hotend, but it's apparently M8. I wish they would just include a connector in the package, but now I have to buy one, ugh. I'd appreciate suggestions for sellers of these M8 push-fit connectors within the EU.

[attachment 86040 IMG_0556.jpg][attachment 86041 IMG_0571.jpg]

Tomas

Try M8 4mm pushfit fitting

Doug

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dougal1957
Tomas
Try M8 4mm pushfit fitting

Thanks, Doug! However, judging from its name ("4MM X M8X1"), that one has fine thread pitch (1 mm) whereas DyzEND has coarse (1.25 mm) thread. I think? :-/

Just can't win can you??

Indeed. I think I will try to find a BSP 1/8 female to M8x1.25 male adapter instead, to use the push-fit connectors I already have. Seems easier to find.

The glass discs I ordered arrived yesterday, so I attached the prepared PEI sheet to one using that 300LSE tape. The PEI sheet was only about 300x300 mm, so it doesn't cover the entire glass area, but I'm okay with that.



I also made a prototype of an effector mount for the DyzeEND-X hotend together with a print cooling fan and an IR probe (mocked as a green printed part, and mounted incorrectly in this photo).



I'm still waiting for the pushfit connector. It turns out it's really hard to find it elsewhere, so I ended up ordering it from Dyze Design across the pond after all.

The printer is starting to take shape. Remaining parts to order:
* 700mm linear rails
* David's IR probe
* Duet Wifi (not strictly necessary, but I want it eventually and I might as well order it together with the probe)

Looking good, nice looking hot end that Dyze unit. Just ordered a Deltaprintr mini hot end for another project, looking forward to trying that.

Make sure to put something insulating over/around the IR sensor PCB, you've got a great location for it - the magnitude of observed effector tilt should be very low, mine is about this close to my heater block. However with mine if the fan shroud its attached to rotates slightly bringing the IR sensor closer to the heater block (despite silicone cover on the heater block and lots of kapton around the IR sensor) the sensor starts to perform erratically, not triggering etc, causing nozzle crashes.

---

Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Interesting. Thanks, Dj, I'll keep that in mind.

Nice. Deltaprintr mini looks even tinier than DyzEND. I like the way it's mounted; I don't particularly like groove mounts.
I wish hotends in general had better options for mounting, both for mounting the hotend itself and for attaching other things (fans and sensors) to its sides.