I'm moving to that thread to solve the PLA issues.

In the previous run I forgot to put back my hot end enclosure. Now I put it back, I didn't cut the board shorter but I put aluminium foil at its edge, I cleared the floor and I moved the insulation so it's flush with the nozzle face. The result is not one tangling until I stopped the machine (and a matching temperature). Several tens of meters of straight filament (I didn't measure). I think that the enclosure is a real game changer.

Then I switched to the supplied PLA. I poured some pellets in the hopper after it was empty of ABS and after some times I set the temperature to 160°C.
I also got many meters of straight filament but... it was very thin and very fast:
extrusion speed: 70,8cm/min
filament diameter: 1,305 ±0,085mm
(I made sure that I measured pure PLA not an ABS mix. Until I get masterbatch I'll use some coloured plastic to mark the coming of a new polymer - anyone doing this ?)

I'd be curious about that hotend enclosure. Can you try without it? I have never needed one. If you end up benefiting from it, can you post a picture?

PLA is tough. Here's a thread on it: http://www.soliforum.com/topic/2847/tem … -filament/

You could try overdrilling the nozzle, but as you saw, the diameter variance is bigger with PLA than ABS. Did you pre-dry the PLA? PLA is pretty hydroscopic.

Cooling the nozzle is indeed important. The idea is that you keep the melt temperature higher than the nozzle/die temperature (the pro extruders do this also). The pro extruders usually don't need a nozzle fan because 80% of their heat comes from barrel shear, so theres a natural temperature gradient between the barrel and nozzle/die. Most of the Filastruder's heat comes from the heater, so we create the thermal gradient with a cooling fan.

I dont know if I understood right, should my nozzle be exposed with fan blowing to get this thermal gradient?

I changed my nozzle today from 1.75 to 3mm  and after read this post I though I should try to run without insulate the nozzle.

But every time I try my temps decrease as soon my fan start: youtu.be/psVj57sa08g
At 9:20 I turned off the fan and you can see my temp going back to normal.

My nozzle was even covered with kapton: i.imgur.com/BXhvywU.jpg

Am I doing something wrong? How you guys get stable temp with nozzle exposed?

I have sure that if I do the same thing as I have done with my 1.75 nozzle I will get stable temps, but dont know if I am ruining this thermal gradient.

If the insulation is slid forward flush with the nozzle how much of a temperature gradient would you get? You'd get some cooling of the nozzle, I suppose, but not as much as if you had a 1/2" exposed.

This kinda stuff is what made me think I'd have to experiment with the fan placement and then of course Ian posted a picture of his vertical extruder without a fan.

The instructions are vague about the insulation placement too even if it matters.

Putting the filastruder vertically was what I was going to try next - have you got a direct link to that thread ?

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In the previous run I forgot to put back my hot end enclosure. Now I put it back, I didn't cut the board shorter but I put aluminium foil at its edge, I cleared the floor and I moved the insulation so it's flush with the nozzle face. The result is not one tangling until I stopped the machine (and a matching temperature). Several tens of meters of straight filament (I didn't measure). I think that the enclosure is a real game changer.

Then I switched to the supplied PLA. I poured some pellets in the hopper after it was empty of ABS and after some times I set the temperature to 160°C.
I also got many meters of straight filament but... it was very thin and very fast:
extrusion speed: 70,8cm/min
filament diameter: 1,305 ±0,085mm
(I made sure that I measured pure PLA not an ABS mix. Until I get masterbatch I'll use some coloured plastic to mark the coming of a new polymer - anyone doing this ?)

The filament needs a completely open path to the ground, as shown in those pictures. Don't worry about it curling left and right on the floor.

A shorter board always reduces kinking, in my experience. There are three factors that influence how long the board should be:
1.) How close the motor support is mounted to the edge of the board
2.) How much axial space is allowed at the motor coupling
3.) How tight the heater barrel is tightened to the flange and coupling.

All of those can stack up to .5"-1". A shorter board never hurts, until it gets so short the filament isnt supported.

I went through a lot of the pictures people have posted of their extruder some working great most with problems and see that there is a lot a varieties of placing the insulation around the nozzle. Some have the nozzle protruding by a 1/2" others have it kinda flush and some have it completely wrapped.

Tim in another thread said:

          "You should tilt the fan away from the nozzle 10-15 degrees, and make sure the insulation is slid forward, flush with             the nozzle. That should take care of your temperature problems."

If the insulation is slid forward flush with the nozzle how much of a temperature gradient would you get? You'd get some cooling of the nozzle, I suppose, but not as much as if you had a 1/2" exposed.

This kinda stuff is what made me think I'd have to experiment with the fan placement and then of course Ian posted a picture of his vertical extruder without a fan.

I sure would like to see "This is what is recommended and this is the reason why" noted in a pamphlet.

Obviously there is confusion that was not clarified in the sticky.

As far as:

           "I'd much rather spend any free time i have on R&D than creating a (massive) post on each design decision, when most of that information has already been documented in the sticky."

Spoken like a true engineer, I spent a good part of my professional career fighting with engineers over documentation, especially easily read informative documentation, I usually lost.

Ralph

I can make a board shorter but I can't make it longer ! So I need to be sure that cutting is the right decision. How can it look too long since the distances are the ones given in the instructions ? The distance from the nozzle (face) to the edge of the board is 10,5cm = 4,17". Cutting 1 inch (2,5cm) seems a big adjustment.

Painters tape sticks to polymers. There's a reason it is used on print beds. Use aluminum foil or nothing.

The board looks a little long relative to the nozzle face. Try cutting an inch off.

One other thing to try - extrude at 170-175C.

Ok so I read again the entire Filastruder Instructions_KS_rev1.pdf document to see if I had missed or mistaken something.
• The distance from the motor board to the edge of the base board is 22" (check)
• The horizontal distance from the top of the guide to the edge of the table (which happens to be the base board) is 3" (check)
• The horizontal distance from the top of the guide to the nozzle is 1,4" (check)
• The distance from the floor to the base board is between 100 and 120cm (check, 105cm)
• The fan almost touches the guide on the wooden block (check, repositioned fan)

With this set-up I get worse results than previously as tangling happens more often, I didn't get more than 2m of straight filament.

Experimenting is great. I am all for it. I am VERY far from being an expert in the field.

What is bothersome is when people don't follow the instructions, then complain their "filastruder" isn't working. Trouble is, they haven't built a filastruder at all - more like a (personsnamehere)struder.

Moral of the story: build as outlined in instructions, you should have a Filastruder that works well.

Heh, yeah, the user can be blamed for not reading the manual.
The thing with this particular product is that the general approximation and lack of information in the instructions as well as the low technicality of the kit lets people think (rightfully or not) that it didn't require an engineer to design it and that it will work as well if not better if some modifications are made.
A manual can always be improved. If something is very important it should be flagged. Most things might be important, you'll say, but there are points of frequent confusion, we found one with the fan and the nozzle. The (uncommon) height of the table should definitely be added.

if you want to gain knowledge, you might not want to hijack this post which is about trouble shooting. (hint:open a new post)

What is bothersome is when people don't follow the instructions, then complain their "filastruder" isn't working. Trouble is, they haven't built a filastruder at all - more like a (personsnamehere)struder.

Moral of the story: build as outlined in instructions, you should have a Filastruder that works well.

Edit: Another example of something like this is the shaft coupling. Some people might think it is a product of being dumb/lazy/etc. I know a fair bit about shaft couplings. Story time!

During my undergraduate studies, I was asked to do some work for a local power plant. This plant was having trouble with their boiler feed pump. This is the pump that feeds the steam generator on a combined cycle powerplant. It was 1,000HP, and the motor and pump were each about the size of a Honda Civic.

(That is just a picture I grabbed off the internet.)

Anyway, this plant was destroying their shaft couplings. These couplings had to withstand around 1200 ft-lbs of torque, and were comprised of dinner plate sized discs. Like this:

They had 8 boiler feed pumps in service, and were destroying roughly one every 2-3 weeks. That tripped the unit offline and resulted in a loss of 200MW of generation for 48 hours or so. Management was not happy.

I walked over to the marketing coordinator's office and asked to borrow their DSLR. I cranked the shutter speed to the max, set it in burst mode, and held the camera under the coupling's cover. In hindsight, it was really dumb and unsafe - if the coupling came apart at that moment I'd probably be missing a hand today. I walked inside and looked through the pictures. The discs were deforming only in one quadrant, which told me it was an alignment issue, not a overload issue. (if aligned properly but overloaded, the discs will deform in all 4 quadrants). The misalignment was fatigue cycling the metal disc packs, leading to premature failure. Some of the pumps exhibited no flex in their couplings. As the couplings detoriated, I could see individual discs failing, and warn management that a failure was imminent. The next time one failed, I helped revise QC/QA processes on the laser-based alignment between the feed pump and motor. No more failures after that.

Back to Filastruder: The shaft coupling was chosen with these goals in mind:
- allow for radial, axial, and angular misalignment
- mechanical fuse functionality (the washer will shear on overload)
- easy to source a replacement if lost or damaged ($1.99 at Lowe's)
- cost: a Lovejoy (or similar) coupling capable of handling the torque would have been the most expensive item on the BOM, by a good bit.

In hindsight, the second goal didn't work too well. The washers ended up having +/-30% difference in thickness, resulting in unpredictable shear loads. Post-KS, I'll probably just use a stainless steel pin instead, and forego the mechanical fuse capability. Maybe a PTC self-resetting fuse on motor current.

How about just trusting the work of myself and all the beta testers, who collectively had over 1,000 hours of runtime during the development stage?

Tim, I don't think it is a lack of trust.  People want to keep improving and evolving things.  When it isn't clear why a decision was made, then they are likely to repeat that effort, or question the reasoning.

I do however agree that it isn't easy (or really possible) to document it all in an easy or time effective way.

When it does come out though, it is worth comment on.

I have for example read all the 58 pages of the beta testing/design programme, but even so I hadn't picked up on this specific point.

Anyway, thanks for all you have done (and are doing!!!).

I know, I know sorry, it just didn't seem logical to be cooling the nozzle.

I don't have any understanding of the extrusion process since my Filastruder is sitting waiting on my 3Dprinter.

I have read the 58 page sticky but I really do not remember any specific points.

Documentation helps to drive sales but so far you seem to be doing well, hopefully it will continue.

Ralph

elmoret wrote:

Most of the Filastruder's heat comes from the heater, so we create the thermal gradient with a cooling fan.

Really Tim we need a phablet titled "Why I did this" to help us understand why in the world you had the fan cooling the nozzle.

That was going to be one of my first modifications to see if I could improve production.

Ralph

How about just trusting the work of myself and all the beta testers, who collectively had over 1,000 hours of runtime during the development stage?

A lot of the design decisions are chronicled in the 58 page sticky. To be honest, I'd much rather spend any free time i have on R&D than creating a (massive) post on each design decision, when most of that information has already been documented in the sticky.

When you buy a Ford Mustang, you don't get a document explaining why they chose the ring clearances and aluminum alloys they chose. You get a car that works as advertised. If you want to try to change it, that's on you. Same story here.