Customised extruder feeder design *No Moving Parts*

[wackojacko]

That's a great print, is that ABS or PLA- also does your filament go under size?

[Eurisko84]

That's a great print, is that ABS or PLA- also does your filament go under size?

Thats ABS - I am also printing in what I *think* is PLA, I ordered ABS but got this clear stuff with a melting point of about 200 deg so im not sure (also not sure how to test it out to make sure either!??)

The filament definately does go undersized - lowest I measured was 1.4mm or so, but ill double check with the purple filament when I get back home.

Cheers,
Eddie

[benglish]

I just found this thread yesterday and am modifying my extruder right now. I'm using the "Pilot Precise V5" pen which needed a just a bit of bending to get the spacing right. It is an awesome design!

I'm looking in my bin of CPU fans and I found a few that you guys might be interested in. I picked them up here-and-there, but I know that I got the CPU fan/heatsink at the local RVAC (USA). The blower is pretty small and looks like it could be made to fit as it has a very slim 10mm profile. 30x30x10mm. It might make a good integrated replacement for the fish-tank air line.

UpBlower.JPG (103.7 KiB) Viewed 1648 times

The CPU fan/heat-sink combo looks like something that could be attached directly to the stepper motor sides, if one could be found that was a bit smaller.

UpHeatsink.JPG (82.71 KiB) Viewed 1648 times

Anyways, perhaps these might be useful to one of you guys.

+Blake

[Eurisko84]

I'm looking in my bin of CPU fans and I found a few that you guys might be interested in. I picked them up here-and-there, but I know that I got the CPU fan/heatsink at the local RVAC (USA). The blower is pretty small and looks like it could be made to fit as it has a very slim 10mm profile. 30x30x10mm. It might make a good integrated replacement for the fish-tank air line.

UpBlower.JPG

That little blower is very interesting! One thing to note, you will want to keep the mass of the head as low as possible (hence the air line) as the standard steel formed plate the head rests on is flimsy and will bounce on fast movements. That will cause the hot end to dig into the model and leave burn marks.... not something you will want.

Let me know how the feeder goes! I've been using mine for about 2 months now and its going great - not once has it slipped or jammed.

Eddie

[mr6k]

Eddie,
I believe a pretty good test to establishif it ABS or PLA is to dissolve it in MEK(Methyl Ethyl Ketone), or Acetone. If it dissolves easily it is probably ABS. as PLA does not react readily to these solvents. Just wipe a peice of the material with the solvent, if it is immediately sticky its probavbly ABS. I do not use Acetone so only assume it has the same reaction as MEK

cheers

Peter

[Eurisko84]

Eddie,
I believe a pretty good test to establishif it ABS or PLA is to dissolve it in MEK(Methyl Ethyl Ketone), or Acetone. If it dissolves easily it is probably ABS. as PLA does not react readily to these solvents. Just wipe a peice of the material with the solvent, if it is immediately sticky its probavbly ABS. I do not use Acetone so only assume it has the same reaction as MEK

cheers

Peter

That is a great test! Cheers Peter, I will test it tonight when I get home!

[DrewPetitclerc]

Do your parts smell like kettle corn when printing? PLA is what you got.
You know what ABS stinks like.

[pleppik]

This was expected, and I thought it was only an issue with my extruder. But you are correct, if you measure the internal diameter of the extruder pipe, you will see its about 1.8mm, so anything bigger gets jammed.

I have run a 2mm drill bit through and shaved it a tad larger - that has allowed me to run even the largest blobs in my purple filament.

I wouldnt recommend doing this, unless you can spare the extra cash for another extruder, should this cause issues later on with regular filament!

Have you experienced any problems with drilling out your feed tube?

I'm very tempted to do this--the pen clip modification works great for undersized filament, but I still have some which is oversized often enough to jam and cause problems.

Also, did you use any special technique, or just hold the block in a vise and go for it?

[Eurisko84]

Have you experienced any problems with drilling out your feed tube?

I'm very tempted to do this--the pen clip modification works great for undersized filament, but I still have some which is oversized often enough to jam and cause problems.

Also, did you use any special technique, or just hold the block in a vise and go for it?

I haven't had any issues at all. As for preparation, nothing more than hold it in a vice, and drill from the top down. Its pretty straight forward

[pleppik]

Have you experienced any problems with drilling out your feed tube?

I'm very tempted to do this--the pen clip modification works great for undersized filament, but I still have some which is oversized often enough to jam and cause problems.

Also, did you use any special technique, or just hold the block in a vise and go for it?

I haven't had any issues at all. As for preparation, nothing more than hold it in a vice, and drill from the top down. Its pretty straight forward

I did it, and doing a test print now.

It was as simple as you described, once I got my act together. I first tried using a cobalt-steel bit ('cuz it's for super-hard materials!) and broke two bits inside the tube. Those were a nuisance to get out.

Then I tried a titanium bit, and it worked like a charm. I guess the titanium bit isn't as brittle, and so works better for softer materials like the brass in the tube.

Drilling out the tube with a 5/64" bit (1.98mm) seems to have removed very little material. But it did smooth out a ridge inside the tube apparently left from the original machining, removing the spot where oversized filament probably got hung up. I'm trying it right now with some filament I measured at 1.85mm.

[Eurisko84]

Let me know how you go mate!

[pleppik]

Let me know how you go mate!

It works great. I'm now able to print well with most of the oversized filament which was jamming before.

I'd recommend this to anyone planning to experiment with different filament suppliers. It takes just a couple minutes, seems almost foolproof (as long as you use the titanium drill bit) and makes a big difference.

[Androo]

I've been printing some parts that have a very large footprint (100+ mm x 130+ mm) but not a whole lot of height (30-50 mm) and I've been getting extreme warping with the ABS. I switched to PLA which resolved it, but at least three or four times now the nozzle has jammed. I've tried printing at PLA temperature, and at ABS temperature (actually works better, but makes support material impossible to remove...fine for these prints, but not in the future!).

I'm wondering what my best strategy is at this point. I think the spring-tensioned extruder is worth a print, and I'm thinking I should maybe drill out my feeder tube, but when I tried to remove my nozzle with the wrench after the last jam it was thoroughly stuck. I'm not sure whether the cause was non-uniformity but I am guessing so...the question is whether it was too large or too small.

To drill out the feeder tube, if I put the liquifier block in an acetone bath is it going to eat the plastic housing on the wiring? If so, does it matter? Is there a way to remove the wires, or are they soldered into the heater block?

My printer does not have the new (hot-running) stepper motor. I have a pre-upgrade Up!, but not one of the initial 100. If I use the spring-tensioned extruder feeder but use only the OEM fan, am I going to run into significant heating issues on my stepper motor?

I hugely appreciate the support and innovation at problem solving that you guys have put forward. The Up! community isn't huge yet, but it is a good one!

[pleppik]

To drill out the feeder tube, if I put the liquifier block in an acetone bath is it going to eat the plastic housing on the wiring? If so, does it matter? Is there a way to remove the wires, or are they soldered into the heater block?

The heater and temperature sensor are held in the hot end by two small screws and a metal plate. Remove the screws and those parts can be easily detached. That will leave you with just the metal block and feed tube.

I would recommend removing the electrical parts before doing any sort of maintenance on the hot end. It prevents a lot of things which could go wrong.

[JuliaDee]

Hi All,

Here's my little contribution, though not quite finished/tested yet. Have added baby fan for cooling instead of compressed air, and made a few slight mods to Drew's design to all for more pressure (as I intend to print in thermoplastic rubbber). Will do a bit more work on it over the weekend and try printing and testing in the next week, or so. Once design is finalozed, I'll upload the files...

<snip>

Cheers
Olaf

Olaf,

I'm intrigued by your mention of printing in thermoplastic rubber; I would really like to be able to do this. Can you share any of your experience with this material with us? Like how/where to get a thermoplastic elastomeric material in filament form to begin with?

Thanks,
Julia

[Eurisko84]

I'm wondering what my best strategy is at this point. I think the spring-tensioned extruder is worth a print, and I'm thinking I should maybe drill out my feeder tube, but when I tried to remove my nozzle with the wrench after the last jam it was thoroughly stuck. I'm not sure whether the cause was non-uniformity but I am guessing so...the question is whether it was too large or too small.

You will need to heat the block completely before trying to remove the nozzle, it is an interference fit piece (and will shrink when cool, making it impossible to remove without breaking it).

I have been printing with this for the last few months now without a single issue - and I have not had to clean the nozzle for months (once every 3 months is what I am seeing).

I have printed in numerous colours, and with the original PP3DP ABS without any problems.

If anyone has any other experiences with this, let me know! I am more then happy to keep modifying/trying new things

Cheers,
Eddie

[DrewPetitclerc]

I have been printing with this for the last few months now without a single issue - and I have not had to clean the nozzle for months (once every 3 months is what I am seeing).

I have printed in numerous colours, and with the original PP3DP ABS without any problems.

If anyone has any other experiences with this, let me know! I am more then happy to keep modifying/trying new things

Cheers,
Eddie

You should place a piece of soft open cell foam rubber around the filament where it enters the plastic tube that runs to the extruder, this will wipe off any particles that are attracted to the static charged plastic and keeps them from being burnt into the nozzle, I've been running the same nozzle since I got my printer and never had to clean it out and our house has an abundance of animals (3 dogs, 4 birds and 2 guinea pigs) and hardwood floors so all that tries to clog the nozzle and does not completely burn up and gets stuck, I learned this trick from the WEB before I got my printer and applied immediately.

Regards
Drew

[iomega]

If anyone has any other experiences with this, let me know! I am more then happy to keep modifying/trying new things

Eddie,
I've been using your design for a few weeks and it's been working well with ABS. But with PLA, the heat from the gear soon causes feeding problems. (I've got the upgraded motherboard). Wondering if this could be alleviated a bit by increasing the pressure from the pen clip. If anybody has played around with this, I'd be interested to hear your experience.

Have you used or had issues with PLA? Is your machine with the upgraded/newer motherboard (ie. much hotter motor)?

A suggested improvement would be to somehow funnel some of the fan air to cool the gear head. This would be much preferred over having to hook up pressurized air lines.

[JuliaDee]

I wish someone would design a printable, sub-miniaturized one of these:

http://www.nex-flow.com/mini_spot_cooler.htm

such a great technology...

[Eurisko84]

If anyone has any other experiences with this, let me know! I am more then happy to keep modifying/trying new things

Eddie,
I've been using your design for a few weeks and it's been working well with ABS. But with PLA, the heat from the gear soon causes feeding problems. (I've got the upgraded motherboard). Wondering if this could be alleviated a bit by increasing the pressure from the pen clip. If anybody has played around with this, I'd be interested to hear your experience.

Have you used or had issues with PLA? Is your machine with the upgraded/newer motherboard (ie. much hotter motor)?

A suggested improvement would be to somehow funnel some of the fan air to cool the gear head. This would be much preferred over having to hook up pressurized air lines.

I'm running the new version with the very hot motor too. The air feed line on the top is designed to take a silicon tube and to be connected to a cheap air pump for a fish tank (see below).



Its less than 20 bucks, and the silicon hose is flexible and can be routed around the machine. This will provide a constant stream of air that cools the gear head directly.

Couple that with a few passive heat sinks (ram heat sinks are small enough to mount on the servo directly) and you have a cool motor that wont be hot enough to soften the PLA before it gets to the heater element.