1 Topic by Otatiaro

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Topic: What would - will - I change in the solidoodle ...

Hello,

That's some days now I'm using my solidoodle.
After "some" tinkering, tuning, etc, it does now work quite reliably, and the result is ok.

There are still 2 things that I think could be improved:

- heat bed : the stock one is soooooo slow and I think it's just a resistor or something, so the temperature over the platform is as non consistant as possible, inducing quite a lot of warping when printing (corners lift off the bed while it cools down because of the gradient of temperature).
- extruder : the stock one is good enough, but I think a Bowden extruder would be a big improvement, I want it to grip the filament better, heat higher (for faster prints), and less moving weight means higher speed and most important, less flexion of the frame (F=m x a, reduce m, you reduce F, and frame flexion is proportionnal to F).

So:

- I already deisgned a PCB heat bed specifically for the Solidoodle, it's currently in fab at Eurocircuits, it's designed very much like the reprap PCB Heatbed MK2 http://www.reprap.org/wiki/PCB_Heatbed_MK2, but included the necessary hardware to drive power (3x MOSFET), and uses surface mount thermistor (9 of them to average the temperature over the board, don't know yet if it's a good idea, will test). I already have an upgraded power supply (12V 20A from Ebay, http://cgi.ebay.fr/ws/eBayISAPI.dll?Vie … 97.l2649). I plan to stick a 3mm glass plate on top of the PCB for stiffness.

- I'll work on a bowden extruder as soon as the heat bed is functional, any idea is welcome.

Thomas.

2 Reply by jefferysanders

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Re: What would - will - I change in the solidoodle ...

I hope you will post plenty of pics when you get that PCB in!!!

3 Reply by nickythegreek

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Re: What would - will - I change in the solidoodle ...

Did you increase the plate size with your PCB or is it going to remain 150mm x 150mm?

4 Reply by Otatiaro

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Re: What would - will - I change in the solidoodle ...

Hello,

No it's still 150mm by 150mm ... I don't need more wink
It could probably be a bit larger.

Anyway, can I find somewhere the dimensions of the of the parts of the solidoodle ? I don't think the solidoodle is open source, but that would help a lot to design compatible parts (thinking about the bowden extruder, for the PCB I measured the screws positions).

Thomas.

5 Reply by Otatiaro

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Re: What would - will - I change in the solidoodle ...

Hello,

Just ordered the parts for the bowden extruder, just missing a cold end (don't know if I can reuse the stock one yet).

Thomas.

6 Reply by Otatiaro

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Re: What would - will - I change in the solidoodle ...

Hello,

Ordered some parts for the bowden extruder.

The stepper motor part is almost finished (just needs the raptor gear) based on airstripper's extruder (modified for reprapworld's push fit connector).

I ordered also a heater block from QU-BD (got a ceramic heater cartridge from reprapworld ... but they send a 24V version although I ordered the 12V version sad ).

What I'm still lacking is the cold end on the printer (all the parts between the hot end and the push fit connector).

I'd need more infos on how to do it properly and where to buy the parts (the PEEK, etc).

Thomas.

7 Reply by Otatiaro (edited by Otatiaro 2013-02-15 14:50:45)

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Re: What would - will - I change in the solidoodle ...

Hello,

Just received the heater PCBs ...

First test on lab power supply to confirm concept and resistance => 3.15V 3.2A so resistance is quite near the expected 1 ohm (0.98 ohm).

At 15W it gets barely noticably warm, just enough to feel it.

Then plugged it directly to the 12V power supply (that I'm already using for the solidoodle, it is a 12V 20A from ebay) and check with temp gun.

It increases temp kind of "fast" (like at least 5°C/s) and the heat is the same (+-2°C) on the whole board (unfortunately I don't have an IR cam to check).

Next step is to order the components to solder on it, and go buy a 15cm x 15cm thin glass plate to glue on.

I'll take pics when it's on the solidoodle.

Thomas.

[EDIT] From 28°C to 100°C in 24s ... that's 3°C/s average. Not that bad big_smile

8 Reply by Otatiaro

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Re: What would - will - I change in the solidoodle ...

Hello,

Doing the first prints on the Bowdendoodle ... it works quite good but the problem is the extruder stepper driver is too light for the task.

I already ordered some TI drivers at pololu and will add active cooling to them.
Heating PCB should beready on monday when I receive the components, I already glued the glass to the PCB.
I also plan to replace the Y intermediate shaft sliders with ball bearings to reduce friction (hence backlash) ... but I don't know how to remove the stock sliders yet sad

Thomas.

9 Reply by Otatiaro

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Re: What would - will - I change in the solidoodle ...

Hello,

Received the parts from Farnell this morning ... and basically my control circuit is not working sad
I'll analyse later why but I need the heater to work fast so I ordered a solid state relay to control it (the cheapest in stock was 40A ... more than 100€ shipped with accessories sad ).

I'll have it tomorrow. This makes the upgrade not really cheap (redesigned PCB would cost about 15€ each for 10 units, the thermistors are cheap, the LEDs too, but the SSR is quite expensive).

Thomas.

10 Reply by Zarni

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Re: What would - will - I change in the solidoodle ...

I'm interested in making my own heatbed PCB as well so very interested to see your design.
I want to go slightly larger so the PCB can have fittings to hold the glass in place without having worry about the clamps being hit by the nozzle and still getting the most out the printer.

Curious though why you just don't use a pair of Mosfets in a darlington pair configuration?
It would be a lot cheaper. It is what my plan has in it, but I do have some FETs kicking about.

11 Reply by Otatiaro

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Re: What would - will - I change in the solidoodle ...

Hello,

Did some prints today with the bowden extruder and the glass bed ... it's a lot better than stock.
It's a lot more precise, less flexion, and the bed heats in about one minute or so, there is no more warping at all.
I can put a pepita on the head so I can make the bed level very easily.

I had to lower the bed temp because the first layers stayed too soft at 95°C.
I also had some issues when printing the fan holder to put on the head because ... well, because I had no fan to blow some air on it. I had to print it very slowly.

Tomorrow I should receive the pololu TI drivers to replace the Allegro 4988 (at least for the extruder, but I bought 8 of them so I'll probably swap all 4), I've put a small fan on the electronics to keep things cold and will add small heatsinks to the TI drivers.

Last step, add ball bearings on the Y intermediate shaft to reduce friction and backlash.

I'll make pics ASAP.

Thomas.

12 Reply by IanJohnson

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Re: What would - will - I change in the solidoodle ...

The ball bearings might be more tricky.  It seems that the holes are 1/2", but the ID of the bearing would need to be 6mm.  Also consider replacing the front idler pulleys with bearings as well, maybe with 608s with a belt guide like this - http://www.thingiverse.com/thing:52023

13 Reply by Otatiaro

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Re: What would - will - I change in the solidoodle ...

Hello,

The BB I have to replace the sliders are 13mm outer diameter. I plan to drill the holes to 13mm and put some printed "washers" on the inside to strengthen them.

Thomas.

14 Reply by Otatiaro

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Re: What would - will - I change in the solidoodle ...

Hello,

Worked full day on the bowdendoodle ...

Received the drivers from Pololu this morning. Installed them, it's a drop in replacement, except that with maximum microstep (default on the solidoodle), it is twice the resolution of the allegro drivers. Just double the steps/mm in the firmware (EEPROM).

Took some time to find the sweet spots for all motors amps, but finally managed to get something quite correct without X motor burning.

I installed the ball bearings on the Y shaft. Took some time because the stock sliders are quite difficult to extract (had to dremel them), quick 13mm drill in the holes (going from 12.7 to 13mm so very easy), and the bearings fit properly. I printed some washers to put on the inner side (frame is 1mm thick and the bearings are 4mm thick, so it's a 3mm thick washer).

I also installed a new heating bloc with a ceramic heater (had a jam and planned to install QU-BD hot end, but jammed immediatly so I mixed up the 2 hot ends ...). M303 showed I could increase the P and I gain and decrease the D gain so it's obviously better.

I'm currently printing a yoda bust to validate the configuration (0.1mm), will take more than 5 hours of print (since the jam I lowered my speeds).

Tomorrow I'll clean up the mess and take a few pictures / movies of it.

Thomas.

15 Reply by IanJohnson

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Re: What would - will - I change in the solidoodle ...

How is the stability of the X carriage?  I think the main test would be some cylinders to make sure they are round.  The reason I want to put bearings in the back is so I can tighten the belts enough to keep the X from wiggling without adding a bunch of Y backlash in the process.  Does the Y slide easily, no bumps where it takes a little more force?

16 Reply by Otatiaro

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Re: What would - will - I change in the solidoodle ...

Hello,

I tightened the belts as much as I could (reasonnably).

Could you point me to a stl that could be used to check it?
Or just a column to print (what diameter, what height)?

Thomas.

PS : yoda is finished, not bad, but I've probably been a bit aggressive on cooling, I have 2 slightly separated layers (one on the back of the head, the other just under the eyes).

17 Reply by Otatiaro

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Re: What would - will - I change in the solidoodle ...

Hello,

Here is a short video of the printer in action.

The infill is not perfect because I'm printing 0.1mm layers with infill every 3 layers only.
On these gears the side blowed by the fan is almost perfect, but the other side is not cooled enough and is less good sad


Thomas.

18 Reply by cmetzel

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Re: What would - will - I change in the solidoodle ...

Excellent work Thomas!  I want one!  haha

19 Reply by Otatiaro

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Re: What would - will - I change in the solidoodle ...

Hello,

The cold end part is airstripper's job modified by someone on the forum (forgot his name, sorry) to adapt push fit conenctors.

The hot end holder is my design, along with the fan holder. It's a direct bolt on to the solidoodle.
I can put the files public if you want to print it, no problem.

I have another heating bed, but the glass on it broke (very weird, a chip broke in the middle at the end of a print). I'm now using "vitroceramique" glass (well it's the french word, don't know the english name), it's ultra expensive (like 600€ per m²), but for this size I paid like 12 or 13€ and it's designed to handle very hard temp changes.

The probem is the glass is glued to the PCB ... I guess the only solution for the other would be to glue another layer of glass (2mm perhaps, that would be a total of 6mm glass). I can send it to someone for the shipping cost plus like 20€ with the 2mm glass glued on it (cost me 75€ each PCB at eurocircuits).

The TI drivers are really better than the Allegro ones ...

More info when I come back from dinner big_smile

Thomas.

20 Reply by jjcuff1

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Re: What would - will - I change in the solidoodle ...

where is this bowden extruder thing? how much it cost and is it a simple buy bolt and play mod or I need lots of soldering and stuff?

Great work this looks awesome. The video appears to have much better print movement (less mass)

in real life does it appear to print better? can you print much faster like 60mm/s
or is just marginal over stock at .1 (other then heat up times)

SD2 owner- Surestepr, filament holder,QUBD servo and heaters, glass bed
Print for fun and for parts for my sports cars
current car is 88 IROC

21 Reply by Otatiaro

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Re: What would - will - I change in the solidoodle ...

Hello,

Here are my Slic3r speed settings :

https://dl.dropbox.com/u/3574941/slic3r.png

And the result :

https://dl.dropbox.com/u/3574941/IMAG0374.jpg

Thomas.

22 Reply by jjcuff1

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Re: What would - will - I change in the solidoodle ...

Wow how does that compare to your best pre bowden  speeds? I am still new to settings

Jim

SD2 owner- Surestepr, filament holder,QUBD servo and heaters, glass bed
Print for fun and for parts for my sports cars
current car is 88 IROC

23 Reply by jjcuff1

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Re: What would - will - I change in the solidoodle ...

And so it is much faster did you see change in quality or about same?
And pre bowden did you play with acceleration to improve speeds.

SD2 owner- Surestepr, filament holder,QUBD servo and heaters, glass bed
Print for fun and for parts for my sports cars
current car is 88 IROC

24 Reply by jjcuff1

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Re: What would - will - I change in the solidoodle ...

so im summary for the bowden deal you need

printed new extruder head and brackets
moved extruder to back of SD and mounted stepper motor and motor frame
mounted existing nozzle to new extruder head
ran temp and heater leads back to extruder (new sensors or just extended old ones?)
then tubing and couplings for filament

just update firmware for new settings?

what is all this TI allegro stuff? You replace your Ardunio?

then you also upgraded the y axis linear bearings?

you have a parts list

thanks sorry for questions

SD2 owner- Surestepr, filament holder,QUBD servo and heaters, glass bed
Print for fun and for parts for my sports cars
current car is 88 IROC

25 Reply by Otatiaro

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Re: What would - will - I change in the solidoodle ...

Hello,

For the bowden :

- print airstripper (modified) extruder
- get the screws (fixnvis) / bearings (1001roulements) / PTFE tube + connectors (reprapworld.com)
- print my hot end holder + accessories (don't know where to put the files though, and what format do you prefer?)
- disassemble the normal extruder, take the motor, hot end / thermistor, etc, and put it on the airstripper extruder
- print

No need to update firmware or anything ... just a few settings to tune on retraction.

The TI drivers : http://www.pololu.com/catalog/product/2133
Drop in replacement for the stock (allegro) ones ... it's a nice upgrade, if you know what you are doing with the current setting (pretty much needed for the bowden extruder, at least on the extruder axis, the bowden tube is a bit harder to drive than the normal extruder for the stepper, with stock driver I got some missing steps).

Don't touch the Y axis sliders if it's working correctly ... it's a nice mod (I still have to replace the other end of the belt with bearings), but it requires quite a lot of work and you can definitely destroy your SD with the dremel.

The bowden mod is nice, you get a much better finish with good print times, but it's also a bit more difficult to operate efficiently, do it if you know what ou are doing.

I find the bowden mod a lot easier to maintain though than the stock extruder, 2 screws to remove the whole hot end bloc, more visibility, etc.

I'm using my bowdendoodle for work for I needed a certain level of precision, that's why I did these mods. If your new to 3D printing, my advice is to get used to the techniques, know how everything works, play a lot with settings, etc, then you'll know what mods you need. I also wanted to mess with it as much as possible because I plan to use it to design something quite similar (not a 3D printer, but XYZ movement too, just with a different head) so it was experiments on the possibilities of the steppers, etc (the NEMA11 on the X axis is a mistake, should have been a NEMA17 ... mine runs at more than 100°C !).

I think the final cost of my solidoodle with the mods is above 1k€ ... that's a lot for hobby use, but well ... it's already paid with the few things I did with it.

Thomas.