MakerGear Forum

This is a simple syringe type Paste Extruder that I am trying to make (Don't get excited yet... it's a work in progress but I thought I'd share anyway). I wanted something that was quick and easy to mount on the M2 (without too much hassle anyway). The idea was to use a rack and pinion setup over the typical screw type plunger to try and keep the stepper motor in the same position so the wire connections stayed the same.
I found the rack and gear setup on Mc-master so I tried to incorporate the rack half right into the plunger of the syringe.
The idea was to fill the syringe with what ever I was trying to extrude, prime the plunger and then just slide it in the mount and screw on the cap and it would hold everything in place.
Once the cap is screwed on the rack and gear should mess up. (this needs a bit of work still.) I have a spare motor so I didn't actually have to remove the stock filament gear.
The z-height is set by just sliding down the switch on the shaft, and I dropped a spare belt block next to the end stop to act as an offset for the syringe mount.

I had my doubts this setup would work... I figured the motor would just skip or the gears would break. After playing around with some g-code and S3d settings I gave it a shot with cake frosting (probably not the best first choice but what the hell) and as I thought the tiny gears on the rack just couldn't take it.

It's back to the drawing board for now... I bought an actual nylon rack (with bigger teeth) from Mc-Master to try again and if that doesn't work I have a longer extruder cable coming too so I can always move the motor and try the typical screw plunger... I'm determined to make this work.

To be continued..............

I don't know what your planning on printing with that setup, frosting for a cake? Anyway you might think about a remote (positive displacement) pump with a nozzle mounted on the print head. High pressure hose could handle frosting or ??

wmgeorge wrote:I don't know what your planning on printing with that setup, frosting for a cake? Anyway you might think about a remote (positive displacement) pump with a nozzle mounted on the print head. High pressure hose could handle frosting or ??

I was thinking of thinking of designer pancakes, think the HBP heats up that much. J/K I have no idea what I would do with this (custom chocolates would be cool) this is just another one of those things I try to make just to see if I can. I live to create

Here is Version 2... I added another few gears for a little more torque and went with bigger teeth this time too.
Even though I bought a nylon rack I decided to try printing one first to see what would happen. This time I made sure the teeth joined with the side walls to add more strength and I also printed them on their side too so the layers didn't run across the teeth.
The syringe still has to be bolted in with the cap but I beefed it up this time so the gear and rack would mess better.
All loaded and ready to go.

So far so good... after about a half hour of trial and error messing with the settings I have it working for the most part. Here is a video of it in action It's pushing out a little to much paste right now as I still need to figure out the correct settings. I need to figure out how to slow down the extrusion some more. I turned the multiplier down as far as I can to .01 and that seemed to help but I think I still need to play with the nozzle diameter and extrusion width to get it to where I need to be. I'm not really sure how all those setting effect everything yet and I'm still playing around but, you can only eat so many calibration cubes before you need to take a break.

Makes me want to eat cake......

I'd call that a success. Sure, you'll tweak it forever, but nice going!

Reminds me of printing with my E3D Volcano head. It doesn't have amazing resolution, but it does have it's own aesthetic.

Instead of tweaking your extrusion multiplier, wouldn't it better to change your extrusion steps in the firmware?

willnewton wrote:Instead of tweaking your extrusion multiplier, wouldn't it better to change your extrusion steps in the firmware?

That's probably exactly what I need to do... I can only fake it enough with the other settings enough to do outlines anything other than that and it would print to many infill lines because I have to say the nozzle diameter is a lot smaller than it is for it to work. I'll have to look into how to do that extrusion step thing next. Thanks for the idea.

You still have the filament diameter set to 1.75, right? Sweet it to 10 or so, let the slicer slow it down a lot for you, and tweak with the extrusion multiplier.

insta wrote:You still have the filament diameter set to 1.75, right? Sweet it to 10 or so, let the slicer slow it down a lot for you, and tweak with the extrusion multiplier.

Oh crap I totally forgot about that setting... let me give that a try before I go messing with the firmware. I would like to be able to switch back and forth without having to reflash everytime. Thanks insta

Nice one Insta!

To avoid firmware loading, you can use M92 Exxx (xxx = steps) to set your extruder steps temporarily. You could put this in your starting G-code in your FFF profile. This code is temporary and will reset to your default after power off/on. You can make it permanent with M500.

If you know what your default steps are, you can enter M92 Exxx (xxx=default steps) into your ending G-code so you won't even have to bother with a power reset.