Lid lifting and cooling-Avoid PLA jams

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Spud
Posts: 36
Joined: Wed Nov 21, 2018 5:18 am

Lid lifting and cooling-Avoid PLA jams

Postby Spud » Tue May 28, 2019 9:46 pm

I wanted to post this to hopefully help others with the same problem.

I had a print fail after 25 hours due to the extruder motor getting too hot, which heated the filament to the point where it couldn't push the softened PLA (not Raise3D PLA) and jammed at the gear that pushes the filament downward.
I had to take the extruder(s) system apart to clear the jam (the heat crammed so much plastic into the extruder system I had to literally drill it out to clear the hard plastic that was packed into it (the red lines).
extruder sysrm.png


When taking the extruder system apart one of the small bearings fell out and since there wasn't anything showing where the parts should go I placed the bearing on the shaft of an extruder similarly to the other extruder's bearing and put the system back together (bearings circled in blue).
Extruder bearing.png
Extruder bearing.png (113.61 KiB) Viewed 609 times


I kept getting the dreaded clicking sound but I could force the filament down using my fingers....so couldn't be a jam.
I inspected the filament drive and noticed the guide (made of black nylon?) wasn't aligned with the gears.
I took it apart and pushed the bearing that had fallen out, into the recessed area the bearing would normally be pressed into.
I used the flat side of the tweezer's handle to press it flush against the black nylon (needs to be squared. If it's not true It could create drag on the extruder and keep it from working -I know from experience! - more clicking).
That fixed the issue. The filament guide was lined up with the gear= no more clicking and no more poor prints.....on that side (the other side is a painful story).
Evidently, if the bearing isn't pressed into the black nylon it will push on the shaft which can move the gear off to one side (slop in the system =Bad BondTech!).



Since I've been printing with the lid off I have still had jams due to the extruder heat (two weeks ago it was hot in California and in my office) so now print with a desk fan blowing directly on the filament extruders.

FYI- I am using the latest firmware that lowers the current to the drivers.

Printing with the lid off is not a good solution. The bed, bearings and everything gets dusty and will need more cleaning than if the printer had its cover on.

So, I am working on a fan system that will keep the extruders cool, let me keep the lid on, and keep the dust out while raising the lid (which is too low) so the tubing doesn't have to rub holes in themselves or the lid.

Update later-
I'll post my solution here once I get the setup working.

If we can plug 12V fans into the two extra spots on the extruder's controller board we could print and mount our own extruder cooler ducting and case closed!!! (see what I did there?)
Can this be used for cooling.jpeg


I asked support and they told me if I used these it would void my warranty.

Does anybody have any feedback on these or other connection points that can be used to run a fan on the extruders while the printer runs?
Last edited by Spud on Sat Jul 13, 2019 6:38 am, edited 1 time in total.
California, USA
R3D Pro2

User avatar
Spud
Posts: 36
Joined: Wed Nov 21, 2018 5:18 am

Lid lifting and cooling-Avoid PLA jams

Postby Spud » Sat Jul 13, 2019 5:41 am

I saw other's had 3D printed vents that the lid rested on which allowed cooler air in helping to keep the motors cooler while lifting the lid up.
Great idea but I didn't want the dust and dirt that clings to the grease-covered rods to get in. It also lets out the fumes that come from the melting plastic.
And somehow the hair I'm loosing finds its way onto my print bed too. I don't need a reminder of that! :shock:

So, I designed and printed a lid lifting, filtered-air intake system that incorporates a .9 amp exhaust fan that sucks air through a filter used for a gas mask that exceeds Hepa's basic filtration req's.

IMG_1440.JPG
front of printer


You will see a couple of wires coming out of the left side of the printer and a (pink) filter about midway inside of the lid on the right. (click the pic so it rotates correctly)

Each side has one printed part for each corner and a midsection that has a carbon filter sheet that slides into it filtering out hair ( :( ) and most of the dust (It looks to me that it's blocking all of the dust but I'm old and can't see the best...but I do notice it being A LOT cleaner than printing with the lid off!)
IMG_1430.JPG
midsection with carbon filter

(In this picture you will see the fan's exhaust hole on the left)

The carbon filter was cut from a blanket used for air conditioners. There's enough for a lifetime;
https://www.amazon.com/gp/product/B074MKZNFW/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

I cut to length four pieces for the midsections and slid them into their channels I designed into the parts.
Filter insert view.JPG
midsection filter channel


If you look close at the bottom of the midsection you'll see two grooves.
One is for a tight fit onto the frame of the R3D Pro2 printer and the other is to accommodate the wires for the fan's power.
The midsections and corner pieces share the same cavities.

I drilled an exit hole for the wires (wires are seen coming out above in the first picture) and connected them to an Arduino sitting below the printer.

I made a terrible looking filter mounting chimney that fits snuggly over the squirrel cage blower (.9 amp has the power to make the whole thing work nicely).
The filter draws hotter air near the top of the lid (which naturally draws in filtered air through the carbon filters) and pushes it out of the exhaust hole shown earlier.
IMG_1441.JPG
mask filter on chimney


The lid can be removed easily and placed back onto the printed parts more easily than the stock printer due to the wider rim and the raised lip on the corner pieces that the lid fits into. Making for a less fiddly lid placement step.
The printed parts all fit together and fit snuggly onto the rim of the printer's frame so everything is tight and wiggly-free.

The lid itself is now at a height to keep the Teflon tubes (filament Bowden tubes) from rubbing on the acrylic lid and also keeps the back of the acrylic lid from getting all marred up from the drag chain cable carrier.
IMG_1431.JPG
drag chain cable carrier



The pink mask-filter is available at hardware stores and cheaper than filters labeled 'HEPA' found online (two filters for the cost of one the R3D Pro2 comes with). They can also be purchased from Amazon.
https://www.amazon.com/3M-Cartridge-60926-Respiratory-Protection/dp/B009POHLRC/ref=sr_1_1?keywords=3M%2BMulti%2BGas%2BVapor%2BCartridge%2C%2BFilter%2B60926%2C%2BP100%2BRespiratory%2BProtection&qid=1562990935&s=electronics&sr=8-1&th=1&psc=1

The fan is available here: https://www.amazon.com/gp/product/B00LPUXVWS/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

I power the fan through the Arduino by using an Adafruit Motor shield. It can be powered by a 12V wall wort but I wanted to play with the full range of the blower and thought maybe, one day I'd add in a temperature probe that controlled the fan's speed. Faster on hot days and turning off when it fell below a certain temp like during the winter when no fan is needed.

When I ran the fan for the first time it had a high pitch sound like a hungry mosquito headed my way from across the room.... I adjusted the frequency in Arduino's sketch and the motor stopped the high pitch making for a quieter office. Another plus for using the Arduino- tuning the fan's motor making it as quiet as possible.

I'm now printing jam-free again with filtered air.

Spud
California, USA
R3D Pro2

noswall
Posts: 3
Joined: Thu Jun 06, 2019 5:57 am

Re: Lid lifting and cooling-Avoid PLA jams

Postby noswall » Wed Jul 17, 2019 4:02 pm

I am also having problems printing certain PLAs, presumably because the extruder motor is getting too hot and transferring that heat to the material. But when I look at the pictures above, it looks like the extruder drives a plastic gear that in turns drives the gear that moves the filament. Can the heat really get through the metal-plastic-metal connection to soften the material? Also, would adding some lithium grease to those gears help?

User avatar
Spud
Posts: 36
Joined: Wed Nov 21, 2018 5:18 am

Re: Lid lifting and cooling-Avoid PLA jams

Postby Spud » Fri Jul 19, 2019 5:42 pm

noswall wrote:I am also having problems printing certain PLAs, presumably because the extruder motor is getting too hot and transferring that heat to the material. But when I look at the pictures above, it looks like the extruder drives a plastic gear that in turns drives the gear that moves the filament. Can the heat really get through the metal-plastic-metal connection to soften the material? Also, would adding some lithium grease to those gears help?


When my prints failed (lid was on) the steppers were close to being too hot to touch.
In my case, the motor's heat moved through its shaft and into the metal gear attached to its shaft. That heated gear then made the PLA soft and the gear pushed the melted PLA into the tube and just kept jamming it in there.....for hours.

Steppers run hot. Not having a fan blowing on it created my problem.
While printing my new setup, I had a desk fan blowing on it = dusty but cool.

A dusty printer that came with an enclosure? Pass!

I haven't had a problem since the blower exhausts the filtered air out.
The stepper is still hot/warm but not scorching.
California, USA
R3D Pro2


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