New extruder design, testers needed.

This is for general discussions. Also FAQ can be found here.

Moderator: speedake95

Post Reply
dognotdog
Posts: 181
Joined: Tue Sep 04, 2012 9:22 pm

Re: New extruder design, testers needed.

Post by dognotdog »

I think the bowden is a good idea even with the rolls on top, as you avoid the movement of the print head tugging on the filament. I'll have to try how the teflon behaves with a simple press-fit, but I suspect it wouldn't hold very well, as its so slippery.

Kjetilei
Posts: 334
Joined: Fri Mar 16, 2012 8:26 pm
Location: Stavanger, Norway

Post by Kjetilei »

I think that using a Bowden cable with my roll holder design will make the back and forth movements of the filament to hard and will cause unwinding of the filament = filament falling down from the roll. With the small diameter rolls I use I have to twist the filament 270-degrees to create enough tension (maybe not the correct word) in the filament that absorbs the back and forth movements to keep it from falling down. I think it would be easier for me to just shot a video to show the effect :)

HLA
Posts: 73
Joined: Sat May 05, 2012 11:35 pm
Location: Vienna, Austria

Post by HLA »

Kjetilei wrote: 4) I really like the PTFE tube solution but since I use the roll holders on top of the printers I think I'll do without. Could you try to come up with a design where threading of the tube is not needed and post it under the "Hacks and printer upgrades"? It could become a popular mod :)
The following snap-in adaptor I tried with a Teflon tube - works like a charm and holds the teflon tube very firmly:
-> http://reprapworld.com/?products_detail ... =1595_1616

@Guillaume: Good-looking update! I would love to test it, but I think my upgrade capacity is limited at the moment after having spent whole day CNC-milling that aluminium plate mod I posted recently. How significant is the improvement in the quality you observed?

User avatar
gfeliksdal
Site Admin
Posts: 405
Joined: Sat Feb 25, 2012 10:40 pm
Location: Netherlands
Contact:

Post by gfeliksdal »

Thanks for the tips, I ordered some ptfe tube and the pneumatics mounting piece. As soon as it arrives I'll design it in and test it.

@ HLA: The quality improvements are not significantly noticable compared to the previous solution. The assembly is a bit stiffer compared to the previous solution, which should result in more consistent printing. Another benefit is that it is a lot easier to maintain. So in case of an extruder jam you are up and running in no time. Another thing is that the wheel is closer to the hot-end barrel, which makes printing with rubber filament a lot more reliable.

HLA
Posts: 73
Joined: Sat May 05, 2012 11:35 pm
Location: Vienna, Austria

Post by HLA »

@Guillaume:
Printing with rubber filament! I would love that, but it seems to me that only 3,00mm is available on the market right now. Do you plan to introduce it in your web-shop anytime soon?

User avatar
gfeliksdal
Site Admin
Posts: 405
Joined: Sat Feb 25, 2012 10:40 pm
Location: Netherlands
Contact:

Post by gfeliksdal »

I ordered it from a dutch supplier. They will produce it next week or week after, so I hope to place it on my webshop soon...

suraki
Posts: 27
Joined: Fri Aug 03, 2012 6:47 pm
Location: Hungary

Post by suraki »

Unfortunately, i can't use this GCODE source, because i need to set the Lash option in SFACT and the Bridge With Multiplier values (as HLA mentioned in another topic) to successful bridge sections. :(

Lioric
Posts: 116
Joined: Wed Aug 15, 2012 1:13 am

Post by Lioric »

I would be a little worried with the fastening of the metal part, without a nut it might get a little loose because of the heat and the forces of the extruder pushing the filament. It might develop some play with time

Obviously adding a slot in the extruder base plate will need support material, but how about adding a guide slot to the upper part:
extruder.jpg

User avatar
gfeliksdal
Site Admin
Posts: 405
Joined: Sat Feb 25, 2012 10:40 pm
Location: Netherlands
Contact:

Post by gfeliksdal »

@ suraki: have you tried printing it already? The settings give me good results. And in theory it should do the same on every Felix. Do you suffer a lot from backlash or have any other troubles?

@ Lioric: This seems like a good idea. Only problem is that the extruder arm will be difficult to be mounted with the right arm you've drawn. Maybe I can get away with only the left arm. I haven't noticed a problem with the nut gone on two printers which are running 1 month straight now.

suraki
Posts: 27
Joined: Fri Aug 03, 2012 6:47 pm
Location: Hungary

Post by suraki »

Hi Guillaume!

Yes,i printed and does not meet my expectations.
http://youtu.be/_RSVVu6RbhY

Image
Image

and one more question: how to disassemble the hot-end? (because of M8 nut removing)

Post Reply