Designing, Specifications & Questions

[Nobias]

This is a question to one and all (including the great Guys & and Gal's at SeeMeCNC). I hope it's in the right thread. I tend to be long winded so if you just want to jump to my point see the big print below. LOL

As John knows real well I am designing (what MessyhairKris referred to as Frankensteining) what i call a Kludge 3D Printer from parts gathered from my continuously growing junk pile and that while i am a newbie I have also researched the %$#@ out of the subject of 3D printing in the last few months. [the scientist in my handle is not just for show]. And is the driving force behind what i want to ask.

Looking thru all the forum topics I cannot find anything about the designing of a machine. And while I enjoy "Designing As I Build" as much as anybody but I am working from a severely restricted budget and am buying only what I absolutely must. So I have to do some designing ahead of time.

designing is closely related to Modding, but Modding topics tend to be on only a few subjects and are usually just about swapping personal modifications, not so much as the philosophy behind it.

Also one thing that many - who have been at this for years - may not realize anymore is that a newbie makes some assumptions that can trip one up... for instance; after taking apart 20+ printers I had a dozen smallish stepper motors and I assumed I had more than enough to build a smallish machine. yet 16 ounces holding torque is a far cry from 68 ounces! <--that figure took me 2 weeks to find alone.

One thing mentioned alot is that a High torque motor is needed for the extruder. I was always confused about this because (1) What does HIGH mean? High - to me - was enough torque to flip my cat 20 feet in the air! and (2) I would assume it takes more torque to move an Axis and all that mass than to poke a filament into a hot tube which is essentially a puddle of melted plastic. i would assume it could be the weakest motor. But all I read HINTS that this is backwards.

Then second to that conundrum is the size of motors in general. You can't just use 'just enough to work' because I have learned that the continuous operating causes overheating and that by using bigger motors you can reduce the heating which also extends their life and avoids failures. As well as burnt fingers.

All these are good questions and confusing ones to newbies and with this whole subject being open source and with a community of nerds (of which I am one so no flames okay?) I would hope that there are a few out there who have 'Technical" knowledge that I can use to save time and money in my project.

I am at the stage where I have gathered enough parts (I hope). And now I need to start putting them together. But I would like it to be as open ended as possible for upgrades and experimentation down the road. since i like to multi-purpose all my projects.

Are there enough people in the group that are technically minded that would consider contributing to a forum thread about the technical aspects of 3D printers?

This would help everyone, not only in designing, but modding and troubleshooting as well. If so please leave a note or comment. Maybe we can get a new section made by the SeeMeCNC guys for this and eventually end up with a document of some kind to share.

tell me what you think.

Oh and 'MessyhairKris' you have the dubious honor of being the source of the idea for the name of my machine: It's now referred to as 'Frankie'.

[Eric]

You can always trade speed for more torque and precision with gearing, and vice versa. For instance, Steve's Extruder(http://shop.seemecnc.com/Steves-Extrude ... -71594.htm) has a significant gear-down between the motor and the pinch rollers. According to the wiki(http://reprap.org/wiki/Seemecnc_h1) its approximately 6.5 to 1.