Rotary Dual Print- Head

[Zeno 25]

Hi there,

i am upgrading my ultimaker orginal from standart dual extrusion to a rotary printhead. I got inspired of the rotary printhead long time ago but i did never started to design my own one for the ultimaker till now.

here are some videos which inspired me:

My goals are:

-having fun

-no oozing

-fast switching between heads

-very light printhead to keep the accelaration high

-printing without prime tower, ooze shield... to save print time

-using magnets for rotary fixing

-using the x-axis to switch between the heads

-get a easy to print design in the end so anybody who want it can print it

-integrate e3d v6 hotends

-upgrade to e3d titan extruder (not on the printhead)

-customise original firmware

-generate printing profiles

I already redisigned my first dual head (never printed only disigned) to version 2

Old design:

New design:

-new bearing rotary axes

-more magnets (clamping of the hotends fan duct)

This only the beta type to try out the mechnical characteristics of the rotary axis.

I already printed 75% of it, pictures coming soon

Feel free to ask questions, and of course if you have further ideas tell me.

Greetings Zeno

[drayson 74]

Nice design!

Reg. questions - never ask for it :-)

How are the dimensions compared with the UMO head (e.g. nozzle position), what about the additional weight and how do you secure the position in the print state?

[Zeno 25]

Nice design!

Reg. questions - never ask for it :-)

How are the dimensions compared with the UMO head (e.g. nozzle position), what about the additional weight and how do you secure the position in the print state?

Thx drayson,

the dimensions are quit well i only loose in X-direction about 7mm (compare to single nozzle) because of the rotation. The rotation is from side to side 24° (12° left / 12° right). In Y-direction i loose about 20mm (maybe i can optomize this down to about 10mm). The position of the print state / the rotation of the half print head is secured by magnets which can be adjusted- sliding around the X-axes centre (ill upload more screen shots soon). I don t compare the weight of the original printhead to the new design right now, but based on the dimension and the fact that the most parts are printed in PLA (axial bearing too - (only balls are steel) ) i think it isn`t much additional weight.

Greetings Zeno

[Deto 4]

Nice, I have been trying to make something like this as well, but didn't get very far.

[Zeno 25]

Nice, I have been trying to make something like this as well, but didn't get very far.

 

Hi Deto,

you want to turn the head by servo?, do you know how to trigger a servo in marlin?

On the first try i want to do the switching with the x-axis, arms and ramps, but maybe after this we could do a servo mod if you want.

[Deto 4]

Yea, was planning on using a 9g servo, easy enough to control from marlin.

My x/y rods are reversed though (um2 style).

I was having problems figuring out how to "lock" it at each position (servos are really not very accurate), never thought of using magnets

[rowiac 53]

@Zeno

I'm glad to see someone working on a dual extrusion mod for the UMO. I will be keeping my eye on this thread. Keep up the good work.

[Zeno 25]

All red parts are neodym magnets (inside the transperent green parts the red ones are more orange), the orange parts are dumpers mounted with the magnets on a adjustible base to calibrate the nozlle hights.

atached some photos of current print status

Maybe i can finish the mechincal work on next sunday, but i could need help with the software / firmware part. I want to use the sripts which can put into the toolchange scripts in simplify3d, but i don t do something like this before.

Edited May 24, 2017 by Guest

[tigertooth4 17]

Great idea! A servo mechanism is worth trying in this case. Mag-attaching hotends and oozing preventing save a lot of time for changing and printing.

I had a similar rotary idea. I'm working on implementing for quite some time. Hoping to test out and post my result soon.

Cheers,

XJ

[DidierKlein 729]

Cool idea! Are you planning to add he ooze shields (or whatever it's called) like in the video?

[Zeno 25]

Mhm, lets call them "nozzle masks".

Yes, but i prefer a softer material like high temperature silicon toned in a mold, to prevent the nozzles for weareout. Trying to do only the standart retraction for the filament (except for the material which dont like to stay a bit longer in the nozzle).

[drayson 74]

well engineered design, curiouse to see it in action.

[Zeno 25]

I made the experience as an designing engineer that you get better results (keep it simple) by talking to a team which gives you total new ideas! Perhaps you´re kinda get blind for it more and more when you get closer to your own approach

[mastory 42]

A good way to latch a device in either of two rotary positions is to use a spring-over-center style mechanism. I have used them a few times in the past. Essentially it consists of a spring that is more relaxed in either of the positions than when the mechanism is 'centered' It can be done with compression springs or extension springs. Extension springs are generally easy to employ this way.

In words, you have a pivoting mechanism that has rigid stop positions in either direction of rotation. In this case, one end of an extension spring would be in a fixed position above the pivot center. The moving end of the spring is attached to the pivoting body so that it toggles between the two positions such that it is more relaxed in either position, and requires further extension to pass 'over center' to get to the other position. The cam ramps in the above pictures could easily achieve the 'switch'. The stiffness can be adjusted by experimenting with different springs and geometry.

I couldn't find a picture of the idea, so I sketched one out. I'll reply with it in my next post.

[mastory 42]

The damn image up loader keeps clipping my jpg. I've tried editing it 3 times. I'm done with it. I'm sorry, but I hope you can see what I'm trying to say above.

[Zeno 25]

great sketch, I can see all details np. Maybe you can use the "snipping tool" if you're an windows user. (search for it and put down a link in your task bar). After activating snipping tool you can marke your image after this it's already in your buffer ore you can save it as an "png" file for the forum.

[Zeno 25]

Thx for bringing in new ideas . A spring meachnism would be working good too. I like the easy adjustable force which can be reached with switching only the spring. I have to put down a link from a german spring shop where you can get almost every spring: "Spring Shop" and even get all technical data and the CAD files . But one thing i like to keep on using the magnets is that the trend of the holding force (force/way diagramm) is exponential compared to the mostly linear trend of a spring. Her a some diagramms:

I want to use the extrem high holding force to fight against the high accelaration of the X-axis to prevent for a swinging printhaed during the printing.

But it would be looking great too:

[drayson 74]

I found this example for a switching mechanism for a UM2 a while ago - works with the spring force of the UM2 nozzle springs to secure the position

http://www.khwelling.nl/3d.um2s.php

[Zeno 25]

Wow, i like how he modded it in such a tiny place and with the in stock metall parts. The acceleration of the x&y- axis dont work against the springs... perfect. Sadly the UMO don't have an active cooled hotend that could be modded this way.

Edited May 25, 2017 by Guest

[Lykle 0]

Lovely design, I like it a lot.

I like the way you use a ramp to switch hot ends.

Only addition I would add is two screws to adjust the height of the nozzle. I know you use the orange bits and the angle with the clamp screws to adjust the height, but I found that adjustments like this are usually better done with actual screw thread. So besides the clamp screw I would use a perpendicular screw to adjust the height.

I really like the idea of magnets, it is a good way to get a positive "click" and the fact that there can be no oozing, lovely.

Lykle

[drayson 74]

Yepp... sadly... but I already started the mill / lathe :-)

[Zeno 25]

XD, oure hackerspace wanted a cnc mill too, but my meight starts building a house and I was tired of engineering after work at this time, but we already bought the spindle, motors and the control... A year later one of oure new members needed a "little project" for his school and asked us if he could use the parts to start building a cnc mill. This guy engineered the design the electrical cabinet... just all on his owne... XD he do such a overkill with this mill, but he did it very well. In about 3 months ore so he will finish the project and we get a cnc in oure hackerspace .

[Zeno 25]

Hi there,

a little status update:

Already printed

(ramps are printed too but they look ugly / forgot to ativate retraction after a TPU print...)

To print: 2x wheels, 2x nozzle masks, titan e3d adapter plate

After the last print i will install the 4,7k resistor for the e3d hotends and flash the firmware. I'll do the first rotary switches maually with s3d console.

[Zeno 25]

Cool idea! Are you planning to add he ooze shields (or whatever it's called) like in the video?

at last i designed the nozzle masks

[Zeno 25]

Lovely design, I like it a lot.

I like the way you use a ramp to switch hot ends.

Only addition I would add is two screws to adjust the height of the nozzle. I know you use the orange bits and the angle with the clamp screws to adjust the height, but I found that adjustments like this are usually better done with actual screw thread. So besides the clamp screw I would use a perpendicular screw to adjust the height.

I really like the idea of magnets, it is a good way to get a positive "click" and the fact that there can be no oozing, lovely.

Lykle

Hi Lykle,

the orange parts are only the buffer which prevent the magnets for cracks. For adjusting the hight you pull the head on one side to the magnets loosen the screw and adjust the angle a little bit (look at the drawing which i added).

Greetings Zeno