Atfer Hbot, go to CoreXY.

Quote
jand
"foudroyante", Google translate was not very helpfull.

Google translate is responsible for a lot of misunderstandings ... imho at least.
look up "synonymes foudroyant" and get the feeling...

I do like the design of your hotbed ... it sure is heavy, designed that way - I "knew"!
With that z-stage, and as a guesstimate I'd say
more than 2/3 of your printers weight now is basically static...
...which is really good but not where this seemed to lead us/me

Too bad now that I'll have to buy the parts in your BOM
_before_ I can see (and gauge) that video.
...just joking ...(1/2 joking?)

@fleming

OK, makes sense.

No it is not for anti backlash. We don't need that on a reprap, because Z in only one way during printing.
I use two nuts to even out the iregularities in the rod. But more important:
A threaded rod is never straight, so at the nut it will make a circular movement. and the system might bind.
The nut can move freely in X and in Y directions.

When I am finished with the first release I will replace the threaded rod with a TR10 leadscrew. So people have a choice. But it has to be METRIC. You DO NOT want imperial.

@Jand
I am starting to put nuts, bolts and washers in the model (to export the final BOM)
I am using this model:
[github.com]
Do you have a final version of the model? any suggestion with nuts and bolts?
Regards

@fleming

Yes That is the latest version.

For the screws, washers and nuts, This is what I counted manually (see BOM in doc folder)

M3 nuts 40
M3 washers 90
M3x12 4
M3x30 40
M3x40 6

M4 nuts 28
M4 washers 116
M4x12 6
M4x16 2
M4x30 4
M4x40 51

I use a washer at both sides. So one at the head and one at the nut.

The screws I use are DIN 7985 (see [www.techwinkel.nl])
They are far cheaper than Allen screws. But allen screws should also be possible.
I am replacing the slotted screws you can see in the photos with these screws.

Do not forget the washers around the bearings. They are important. They are in de model.

The CAD (viacad) program I use is not very helpfull when inserting screws in holes and add whashers and nuts. I should have done it from the start, now it is a lot of work.
But if you want to do it and send me the step file that would be great.

Edited 1 time(s). Last edit at 05/13/2014 07:49AM by jand.

Hi Jand,

Can you confirm the bearings that you used? Are they 625Z or the 624Z?

Thanks

Bearings are 624zz, so with 4mm inner diameter.

All lower bearings have to be Flanged bearings, for the top bearings you can use normal bearings, but it is probably better to use flanged bearings for both top and bottom.

HI!

after many time away (family/personals problems...), I'm here and that printer is alive!

I have made many discovery... The first one, 0.9° stepper motor make really less noise than 1.8° (maybe because their are more powerfull too) . :-D

The second one, and not only for that printer but for ALL hbot and CoreXY gantry. With Marlin & Repetier firmware.

I have seen many time ago that link:
https://audiots.wordpress.com/2013/05/26/going-back-no-corexy-for-a-while/

That describe not round circle with Corexy system.
I have uploaded EXACTLY my same firmware (repetier), just change that line: #define DRIVE_SYSTEM 0 (from 1 before)

and M206 T3 P3/P7 X458 to divide by square(2). And now circle are round, space between infill line have all equal distance. The only downside for the moment, the build area is smaller and the printer is 45° rotated.

Keep update....

Edited 1 time(s). Last edit at 06/01/2014 12:33PM by zelogik.

Quote
zelogik
That describe not round circle with Corexy system.
I have uploaded EXACTLY my same firmware (repetier), just change that line: #define DRIVE_SYSTEM 0 (from 1 before)

and M206 T3 P3/P7 X458 to divide by square(2). And now circle are round, space between infill line have all equal distance. The only downside for the moment, the build area is smaller and the printer is 45° rotated.

Is this a general bug fix for Marlin, or only a fix for hbot and CoreXY?

It's just a really weird fix for any hbot/corexy.
Somebody need to look for a workaround, bugfix on marlin and repetier, and sailfish may have this bug too.
The problem for me is that i dont have time and knowledges to trying to fixing that.

I just seen (like on the blog too) that it is not an hardware problem, but a firmware bug.

Welcome back - hope everything is amicably solved.

Quote
zelogik
I have made many discovery... The first one, 0.9° stepper motor make really less noise than 1.8° (maybe because their are more powerfull too) . :-D

So you did buy .9° motors and found them "more powerful" ? ... actually they are only "more powerful" because (I bet) they are 48mm long vs. 40mm or less in
your previous design (but you knew that!). In general, especially with microstepping, you "loose" up to 30% power doubling the resolution (magnet related).

Quote

The second one, and not only for that printer but for ALL hbot and CoreXY gantry. With Marlin & Repetier firmware.
... not round circle with Corexy system.
I have uploaded EXACTLY my same firmware (repetier), just change that line: #define DRIVE_SYSTEM 0 (from 1 before)

Have you actually used Marlin firmware and "printed biggest circle that fits on your buildplate" ? If not please do...
Marcus Littwin of Repetier is available around the corner ... [forums.reprap.org]

Regards
Reinhold

P.S.: Could you have a look at the issues reported below and report ?
[github.com]
[github.com]

Hi zelogik and jand, is there any reason why the motor mount cannot be direct? What I mean is, remove the 2 idler pulleys in the motor block, and the 90degree bend from motor block to XY block. I have attached a picture to make it clearer.

@genelmx
You are removing the "belt tensioner".
[en.wikipedia.org]

...possible but probably not the best of ideas

@Reinhold
Thanks! I'm aware of it but, suppose I have another way of tensioning the belt (on the carriage), what other purpose do those two idlers serve? I am looking to keep things as compact as possible.

I am going to print and test it out anyway but was hoping jand or zelogik could save me some time if they have already tried it.

@genelmx: First you do not gain any buildspace by removing the idlers. You do however reduce the amount of plastic and it will probably be easier to print in ABS. But you have to do the tensioning somewhere else. When you do it on th carriage you will probably loose buildspace in X direction. You have to carefully check the belt path so that motor pulley and the bearings line up correctly

I know, I had the same feeling, but found this the best solution. Zelogik is a clever designer!

Edited 1 time(s). Last edit at 06/02/2014 06:20AM by jand.

Quote
genelmx
I am going to print and test it out anyway...

Testing "something simplified" is always a good idea...
after all that's how we found out that in a simple atom there's a core (not xy though )
You may want to have a look at some of those who have gone "your" route before:
Most popular corexy on the german reprap site: sparkcube ...has been built at least 50x by now.

Regards
Reinhold
P.S.: You'll be back - thanks zelogik

@Reinhold, Yes, I know that 48mm motor length is stronger than 40mm one , But I have choose 2.4A. So they don't run at 100% efficiency but make less noise (now i have the problem of the fan noise to have a correct WAF )
And I have alerady checked Github (you even can seen my nickname around )

I need to take photo on two print, one in CoreXY mode, the other in normal cartesian / square(2). almost same gcode...
And yes I need to test with marlin, but the last time i have tested the last git of marlin (5 or 6 months ago) I think I have already seen this 'bug' without be sure it's a firmware or hardware problem.

@genelmx: The only downside of what you want to do is only the removing of my "cool" idler AND if your teeth puller and bearing idler have not exactly the same diameter the alignement of belt don't be good. (Yes i know not all belt need to be parallel but it's nicer )
The second thing is that you can change the motor pulley diameter with what you want without changing anything (12teeth to 30teeth without problems normally).
I hope to helping you.

If my memory is correct you will just remove 32mm on each side without increase the build area ...

@jand: Thanks for your compliments

You can see photo of the problem there:
http://forums.reprap.org/read.php?267,364017

And yes, i have really poor filament quality :-D

@zelogik I did not see this behavior on my printer.

In your first picture this is the infill we are looking at, right? If I see it correctly you get two infill lines next to each other and then a gap of one infill line.

If you want I can print the same object to compare.
I have a RAMPS 1.2 board and marlin firmware.

@jand, dont need to print exactly the same object. Can you take a picture of a top of print or/and a rectilinear filling during printing :-)

Repetier bug... Maybe tomorrow i will give a try with marlin.

Quote
zelogik
..checked Github (you even can seen my nickname around )

Sry ... usually I make a point to read all, especially the end ... just missed you!

Quote
zelogik
I need to take photo on two print,..

Please use Sidelights (éclairage oblique) to accentuate the emerging texture and material and switch your camera to "aperture mode" with the smallest aperture you can hold steady. There will be much more to see than just infill-infill-empty-infill-infill

Quote
zelogik
(12teeth to 30teeth without problems normally).

WHERE do I get 12teeth, 5mm bore GT2 pulley ??? PLEASE!

BTW: HERE is 128microstep driver for RADDS if your quest for quiet resolution still doesn't satisfy your wife...

Regards
Reinhold

Oups the smallest GT2 alu pulley i have is 16teeth

I have already seen the RADDS & 128steps .... but grrr I need to stop to spending so much money on that :-p

Quote
zelogik
@jand, dont need to print exactly the same object. Can you take a picture of a top of print or/and a rectilinear filling during printing :-)
Repetier bug... Maybe tomorrow i will give a try with marlin.

Did you (both) see THIS

Quote
Repetier (Marcus Littwin)
The DRV8825 often used for 32 microstepping needs longer step high signals.
So firmware is too fast. Solution is to set stepper high delay to 1 or 2us (RADDS).
In online config tool you need to enable expert settings to see that option.

...I believe jand is using A4988 (and Marlin) - correct?

hum look interesting...

I have seen the first link but seem to be a RADDS. And I have tested with DRV8825 and A49XX ... and the result was the same.(I my memory don't play with me...)

I did a test print. It has a regular infill pattern, but I am having a hard time to take a reasonable picture. Wil try again tomorrow with daylight.

Bad news ... i have exactly the same problem with the last git of marlin.
I thinking a little more it's can be backlash ... Maybe igus bush are quiet but have little more gap.

Now i have doubt with what is the problem...


Edit: Or it's perpendicular axis problem between X and Y !!! Somebody have an easy way for controlling that ?

Edited 1 time(s). Last edit at 06/03/2014 02:49PM by zelogik.

Quote
zelogik
Edit: Or it's perpendicular axis problem between X and Y !!! Somebody have an easy way for controlling that ?

I am (really) not sure what you are telling (me) but does:
"Print (a lot of) large X's" answer your "controlling" needs?
Those diagonals do engage motors independently
(most perpendicular, linearly independent)

But you are infilling and from the pics you did show I am talking b*llsh*t here
M17?...it's not doublestepping (again)...

Regards
Reinhold

Like I promised an example from my printer.
I am running Marlin. Not sure which version, but the files are from April 13 2014.
File was sliced with Cura: 0.2 mm layerheight an 50% infill.



More images here: [imgur.com]

BTW: the red carriage is printed with 100 mm/s. See [youtu.be]

Edit: It took a little longer than expected, because my new phone arrived yesterday and I just had to play with it. Pictures were taken with that.
Size is 40x40 mm and the hole is 20mm. Measured: 39.9x39.9 and the hole is between 19.9 and 19.95.

Edited 2 time(s). Last edit at 06/04/2014 04:41PM by jand.

Wow, from the Youtube video, that thing is flying. I can't imagine how fast you'd get by using a Bowden-style extruder, but then, it's probably going as fast as the hotend/extruder can handle already...

@Jand: Nice print , you don't have the same problems as me.

I have installed Marlin, and slice everything with Cura too .... I have checked:
- Motor pulley tightening with the motor
- perpendicularity of X and Y
- different tension of belt
- even differente step between X and Y
- backlash.... as I can.

Now I have choice between:
- different diameter of Pulley?
- voltage of stepper ?!?
- the "roundness" of one or two idler teeth pulley
- perpendicularity of the nozzle with Z table?
- anything else ?
- gap with bush instead of LM8UU
- DRV8825 are buggy ..?!?
- anything else ?

Edited 1 time(s). Last edit at 06/04/2014 05:08PM by zelogik.

zelogik,

how many full steps/revolution on your steppers? 200?

DRV8825 step rate? 32x?

Are you using an ARM board now or RAMPS?

I wonder if you're microstep rate is too high.

---

- akhlut

Just remember - Iterate, Iterate, Iterate!

[myhomelessmind.blogspot.com]