Print with rubber on your Lulzbot!

Help with printing with specific plastic filaments.
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piercet
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Re: Print with rubber on your Lulzbot!

Post by piercet » Wed Nov 27, 2013 7:59 pm

Per the other belt drive thread, but in order to keep all the development files in the same thread, here is a theoretical belt drive flexystruder (normal, not quickfit for now). I will make a quickfit variant of it next since I'll need one for my machine if nothing else. It's 2 parts at the moment, an optional belt tensioner designed to have a threaded insert in the hole in the side. the base belt drive flexystruder can be used without the tensioner plate, but the nema mount might be too thin without it. the tensioner is designed to sandwich between the base and the motor, turn an M3 screw in the threaded insert to put tension on the belt with the motor losely in place, then tighten all 4 motor mount bolts when you have the desired belt tension in place. also should prevent belt tension loss over time.
beltflexy.png
feel free to use the design in any way you see fit.

Parts required for the belt mod (aside from already required flexystruder parts)
1. gt2 belt, 2mm pitch, 200T, 400mm length, 6mm-with, fiberglass-reinforced, closed-loop
2. gt2 65T plastic pulley w/8mm bore, flanges, set-screw
3. gt2 17T aluminum pulley w/5mm bore, flanges, set-screw
the gear set can be purchased here with the belt for $25. select "belt and gears only from the drop down instead of the full kit for the other style extruder: http://store.terawattindustries.com/77- ... ma17_motor
4. an additional heat set insert
5. an additional bolt that fits the heat set insert.

edit: to use this extruder in place of a wade's geared herringbone version, you may need to adjust the extruder steps per mm line of your controller configuration. The measurements to do so accuratly are as follows:

Extruder Calibration (borrowed from the reprapwiki)

The procedure to calibrate the belt flexystruder is as follows:
Measure the Outer Diameter of the knurled (hobbed) area of yiur hobbed bolt, preferably with digital calipers. The exact Outer Diameter will depend on things like manufacturer and batch. this should be the narrowest point of your bolt.
Calculate the gear ratio between small and larger pulley (example below is valid for the specified pulleys).
Find the step angle for the motor - most common NEMA17 motors are 200 steps per revolution.
Find the microstepping value supported by your stepper drivers. This usually depends on brand of driver and type of control electronics.
Use the following formula:
steps_per_mm = (gear_ratio / (hobbed_bolt_OD * Pi)) * ((360 / motor_step_size) * (1 / driver_microstepping))


For example:
A hobbed bolt where the knurled bolt measures 7.52mm in outer-diameter (O.D.)
The gear ratio for a 17-to-65-tooth gear system is ~3.8235. In other words, ~3.8235 revolutions of the smaller gear equal one revolution of the larger gear.
NEMA17 motors are common with 1.8 step angle and RAMPS 1.4 with pololu drivers supports 1/16 microstepping.

steps_per_mm = (3.8235 / (7.52 * 3.1416)) * ((360 / 1.8) * (1 / 1/16)) = 517.8957 ~= 517.9


I "think" that you would replace the "800" in this line: DEFAULT_AXIS_STEPS_PER_UNIT {44.7,44.7,1512,800) with that value. I haven't tried it yet though.
Attachments
flexystruder_03_mod_belt_1a_tensioner.stl
(63.95 KiB) Downloaded 78 times
flexystruder_03_mod_belt_1a_base.stl
(266.88 KiB) Downloaded 68 times
flexystruder_03_mod_belt_1a.stp
(3.49 MiB) Downloaded 58 times
flexystruder_03_mod_belt_1a.dwg
(954.12 KiB) Downloaded 66 times

bam
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Re: Print with rubber on your Lulzbot!

Post by bam » Thu Dec 05, 2013 9:16 am

piercet wrote:Per the other belt drive thread, but in order to keep all the development files in the same thread, here is a theoretical belt drive flexystruder (normal, not quickfit for now). I will make a quickfit variant of it next since I'll need one for my machine if nothing else. It's 2 parts at the moment, an optional belt tensioner designed to have a threaded insert in the hole in the side. the base belt drive flexystruder can be used without the tensioner plate, but the nema mount might be too thin without it.
I really like this. Super excited to see one running.

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piercet
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Re: Print with rubber on your Lulzbot!

Post by piercet » Thu Dec 05, 2013 12:27 pm

Glad you like it! Belt and pulley should be here tuesday-ish? The order got stuck in processing for a few days, but it has shipped.

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Re: Print with rubber on your Lulzbot!

Post by jebba » Tue Dec 10, 2013 11:23 am

We've now printed some NinjaFlex filament with the Flexystruder (dual, no less) in addition to the FilaFlex. The NinjaFlex is easier to print, but not as flexible. It is a far more consistent diameter too.

-Jeff

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piercet
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Re: Print with rubber on your Lulzbot!

Post by piercet » Tue Dec 10, 2013 11:35 am

Did you print a ninja with it? It's important to have flexibility in your ninjas just in case!

Belt and pulley assembly has not arrived yet, so I haven't had a chance to play with the belt extruder yet.

1013
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Re: Print with rubber on your Lulzbot!

Post by 1013 » Tue Dec 10, 2013 7:59 pm

jebba wrote:We've now printed some NinjaFlex filament with the Flexystruder (dual, no less) in addition to the FilaFlex. The NinjaFlex is easier to print, but not as flexible. It is a far more consistent diameter too.

-Jeff
Is this material available from a US distributor yet?

been using the flexPLA for a while with good results (dual extrude with HIPS too), but urethane is very interesting too

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Re: Print with rubber on your Lulzbot!

Post by jebba » Tue Dec 10, 2013 8:16 pm

Urethane is way more flexible than the soft/flexible PLA. We're working on getting both into our store. Also, the urethane stuff is *VERY* strong.

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piercet
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Re: Print with rubber on your Lulzbot!

Post by piercet » Thu Dec 12, 2013 12:06 pm

Apperently the belt parts still haven't even shipped yet from the other vendor. No idea what the delay is. I guess I'll keep playing with the Z-rail project until they do for now.

bam
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Re: Print with rubber on your Lulzbot!

Post by bam » Mon Dec 16, 2013 12:48 pm

The Flexystruder V0.5 is here!

I'm really happy with the way that the newest version of the flexystruder is printing, And I think it's time to get some feedback from our users.
So far we've tested it with flexible PLA, filaflex (black and pink) and Ninjaflex (Sapphire, white and red) without issues. The flexystruder "will" print with ABS, PLA or other hard polymers, but since this wears out the PTFE lining we suggest only printing small amounts when you need to hotswap between flexible and rigid materials.
IMG_2598.JPG
An octopus as the flexystruder's first print with Ninjaflex (it's just how we roll)
IMG_2599.JPG
Dual extruder test parts - ABS plastic with sapphire Ninjaflex. The bond between the two materials is super solid and the finished print bounces just like a golf ball.
IMG_2596.JPG
An inside out spiral vase we printed to test hot-swaping the urethane. It's impressively strong, much more tear resistant than equivalent ABS or PLA prints
Up on http://devel.lulzbot.com/ we've posted an updated bill of materials, as well as assembly instructions. Look under TAZ/accessories/flexystruder

Let me know if you've got any questions/comments/cool things to share

-bam
Last edited by bam on Wed Feb 12, 2014 3:37 pm, edited 2 times in total.

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piercet
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Re: Print with rubber on your Lulzbot!

Post by piercet » Mon Dec 16, 2013 3:09 pm

Nice job! I like the improved threaded fitting on the side. Good job! One possible addition to the bill of materials: a press fit thumb screw cap fitting for the M5 bolt?

I'll update the belt design sometime in here. assuming I ever see my belt parts haha.

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