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Momentary switch to longer action

Posted: Mon May 08, 2017 10:07 pm
by NormL1
I have a Rostock Max 3, but, this is a question for my AON-M, which doesn't really have a forum. The Aon-M print box is 454 x 454 x 640mm build chamber, so, I am feeding it some big rolls. The stepper sits on top of the hot end and the PTFE tubes are exceedingly long because of it. I have a Push Plastics 10Kg roll of PTEG and it always gets to the point of initial resistance and can't get past it. I now have a shaft with bearings and a bearing roller assembly, neither of which helped a lot with the initial resistance. The stock system does spin rolls of 4Kg from 3DXTech without issue

I got the idea to make a clear plastic bucket with a good seal that I could move a powered lid from filament to filament bucket. The idea being to have two lids that are powered by a stepper motor and a tension monitor to turn the stepper on and off. I have in mind a slightly different monitor from this, but, not materially different. http://www.thingiverse.com/thing:3968 I got the idea from this http://www.thingiverse.com/thing:1001522 for the entire project, but, it wouldn't work in a bucket that was sealed from moisture.

Since it will be a separate system from the printer with the exception of those moments of tension, I was going to power it with a USB cable connected to a good USB power supply. That would give me 2.4 amps at 5v and the stepper I bought for experimentation is 2v at 1.2 amp. A regulator to step the voltage down to 2v will be in the system. The regulator in my hand is rated at 2 amps with 3 at peak.

Now my question. Does anyone know how to convert a trip signal that is going to be momentary into a longer signal to spin out enough filament? Maybe the trip signal will be long enough to get enough filament out, but, my gut tells me no. I can guess it would be a relay, but, how do I size it and get adjust-ability?

Re: Momentary switch to longer action

Posted: Tue May 09, 2017 9:34 am
by nebbian

Re: Momentary switch to longer action

Posted: Tue May 09, 2017 9:57 am
by NormL1
Exactly what I need, thanks!

Re: Momentary switch to longer action

Posted: Mon Sep 11, 2017 11:17 pm
by NormL1
OK, I was an idiot and the Ardurino board could do everything I was worried about. I ended up printing this:
Image
Image

My design was to have portions glued down that I would then just screw working sections onto with big printed 5/8"x11 screws. The thought was that it would thereby allow me to have more latitude. I don't know if I am still with that line of thinking. I used a commercial grade Rubbermaid polycarbonate food container from webstaurant.com. After I got going with it I quickly saw that I didn't need two of the boards that I thought I did. The only design changes that I had to make to get different pull tension actuation was different designs of the PTFE holder. I found that as little as possible must touch the PTFE, basically as tension builds, if it is grabbing and not sliding on the PTFE tube, it will snap the upright. I ended up printing the PTFE holders on Shapeways as I am still not good enough to go super thin yet.

Anyway, it works and the AON can print big stuff with no feed issues now, which was my big issue with it. It is currently printing a fender for an Ariel Atom that is a 115 hour print. With the AON, I have it set up for hardly any pull tension at all with just enough to get over the threshold of false positives.

Yes, that is the power supply from my Rostock as it is now 24v

[youtube]https://www.youtube.com/watch?v=JoljTK5l15s[/youtube]
https://www.youtube.com/watch?v=JoljTK5l15s