Paste extruder active development?

Hi everybody,

I am looking into building a syringe or other type of paste extruder. While browsing true the blog archive and the wiki it looked to me like development of a syringe was abandoned long ago in favor of the thermoplastic extruder and never picked up again as a secondary tool.
Then there is the paste extruder [reprap.org] which seems to be in favor over a syringe for extruding paste because of the larger volume but that page was last updated in 2007. Is there anybody actively developing a paste tool and is there a more recent development version that I could build because it seems that everybody is reinventing the wheel and building theirs from scratch. Or is the paste extruder mentioned on the reprap site the last 'official' version? Maybe Zach has some more info on his designs in sourceforge?
Thanks for shedding some light on the state of paste extruders!

d

Check fab@home, they are actively using syringe extruders.

[forums.reprap.org]

is a link to a thread just a few down from yours. Victor has a 5cc syringe working and is working on a 50cc one.

Looks good

Hi unfold,

i think the f@h-dispenser is the best available kit actually.

I have some comercial pneumatic dispensers too (look here: [forums.reprap.org] ) but the pressure/time-behaviour wasn't precise enough for my needs, so i searched another, found the f@h too but decised to build my own because of the costs and shipping.

My design was completely free as i've all the parts and tools ready at home.

When in need for a bigger volume or a different setup, then it's simply milling some fitting new blades and ataching a bigger/stronger stepper - i have some tens steppers in different sizes and some stes of microstepping-drivers in my fundus, so i'll prefer to design and build them anew instead of ordering kits ...

Viktor

@MrSeeker: Definitely an option, but I can remember some talk about it being not realy compatible with the software? Ill look into it again. But I am still wondering if all dev. has stopped in the RR community on paste extruders. I read the whole blog history this week to get some better perspective on the development history of the reprap and there used to be a lot of talk about Syringe/peristaltic
/'soda bottle' paste extruders.

@ Arvin: yes, checked that one an talked a bit with viktor but that system is used as a fixed printhead (moving table). My feeling says that it is to high and top heavy to use as a moving head. Better use a linear stepper (expensive) or some gears like the 2005 syringe tool: [staff.bath.ac.uk]

@ Viktor: Thanks for the link to the pneumatic dispenser. You're the one always replying to my questions and thats really appreciated (just had to mention). Unfortunately I'm a designer with a love for tinkering and a 'just enough' knowledge of electronics, programming, mechanics etc. You're the kind of guy who can start from scratch with this stuff and build amazing tools, I need to hack kits . I'll definitely take a second look at the f@h tool. You're not aware of major incompatibilities? I heard that BfB is also developing a RR compatible syringe.

Hi unfold,

... we had recently a short dispute in the f@h-forums about combining the efforts of f@h and reprap - with minor criticism from me 'cause lack of 'evolving vitamines' in the f@h-world because of the already mature status - in respect to the conceptionally unfinished but evolving status or the reprap what's activating much more enthusiasts.

Evan mentioned some future changes in the direction of creating interconnections between f@h, reprap and other RP-systems, so you'll be able to combine any of the parts, tools and concepts and build your own concept at will.

I started this same theme five or six times over the last two years here and in the f@h-forum - so some synergetic adoptions are only a matter of time

Viktor

Edited 1 time(s). Last edit at 03/04/2009 01:49PM by Viktor.

I think the main barrier to putting a f@h syringe tool on RepRap was the fact that it is stepper driver and the RepRap extruder was DC motor driven. The latest RepRap extruder is stepper driven so should be hardware and software compatible with a stepper driven syringe.

If you build a RepRap then it would be very easy to make something along the lines of Viktor's but in plastic.

---

[www.hydraraptor.blogspot.com]

... for my dispenser i've reprogrammed a 'basic-stamp' as manually configurable and/or analogue (or PWM-) driven single-stepper-controller with an atached IMT901-driver.

You can use a VCO-IC or a NE555-timer with adjustable time-base for this too.

So you'll give PWM or DA out and the adjustable oszillator converts into puls-rate for the stepper.

But it would be much more accurate when configuring or steering per serial bus - so you'll have much higher accuracy and linearity than with PWM or DA/AD-conversion.

The solution with the 'basic-stamp' is easier for me because i have the IDE and some of the stamps in my stock, so it's only one minute reprogramming for changing the parameters and bandwith - this saves much work especially in the testing phase ...

Viktor