Sunday, February 22, 2015

3d Printer Part 15

I moved the gantry back.. too freaking much! Nice. I swear sometimes I move freely between and hacker and hack. Well, I'm not moving it again so all of you can just deal with it. On top of that, for this post I ran in there to take a picture because I added an accent light and it was cool. I connected it backwards and fried the voltage inverter for the light- awesome.

I did my calculations for calibrations. I'm using this page and this calculator works nicely. Below are my printer's axis vitals.

X axis:
Motor M42SP-6TG with a 7.5º step and a 16 tooth gear driving a belt that looks like it might have 1mm pitch

M92 X20.83

Y axis:
NEMA 17 with a 1.8º step and a 20 tooth gear driving an MXL belt with a pitch of 2.03mm
M92 Y78.82

Z axis:
NEMA 17 with a 1.8º step directly driving an SAE 5/16 rod with 16 threads per inch.
M92 Z2267.72
All of these are on A4988 stepper drivers with 16 microstep capability so the calculations take this into account.

I know this is dry reading but I kind of am just documenting my shiz for later reference. Anyone using similar equipment would get similar results. These are all preliminary too and I'll have to devise a way to test the accuracy of all of this.

Saturday, February 21, 2015

3d Printer Part 14

Tonite, I modified a few reset buttons(dpst) from old computers from normally open to normally closed. Those switches work nicely because they come with the Dupont plugs that fit my RAMPS shield.

They are going to be used as end stops(currently I'm just using jumpers) The end stops are needed to establish an origin in the Cartesian geometry the printer uses to to determine where to put plastic. It won't be to long before I can start calibrating and then I can run the slicer program.

Before I do that, I'm going to move the gantry back a couple inches because in my lack of planning(true intp), the build bed doesn't get enough travel under where the j head is going to traverse.

I get the slicer dealie running, that'll be a cool video! Imma have to find some nice funky music for it.

I know I didn't mention I was going to do this but hopefully I can put together the protection circuit for my sound-card oscilloscope this weekend. I've wanted an oscilloscope since I was a teenager. It will cost me $6! Weeee!

Also, the heated bed I ordered doesn't fit my printer so it will go on the next one and I need to make one that will fit this build or widen it- bleh.

A need for wire control:

Fortuitously, the gantry is only held there by 2 screws so all I need do is drill the two new holes for the guide rods and put those aforementioned screws back in at the new position. Of course drilling the new holes is tricky because I have to use the top board there as a template and do the drilling on the drill press so it's nice and vertical.

Saturday, February 14, 2015

3d Printer Part 13

As one could see in this video, the bed slides on rods which ran through holes drilled in pine furring strip. It was wicked tight so I bored them out a bit which resulted in a loss of precision. I was going to make that up but devising some adjustment dealie. When I saw(and heard) how it chatters I knew I needed a harder point of contact to lessen the friction. Even a hard wood would have improved the ride of the thing. I bought some nuts which fit on the rods nicely and slid freely. I fashioned a magnificent bracket which holds said nuts in a precise manner:

Sadly any weight caused those hard nuts to bite my rods. That's right- my nuts bit my rod. I rolled a small piece of sand paper to round off the the inner threads of deez nutz and BAM! It didn't work. Still binding.

Out in the garage I found some brass or bronze nuts which although they didn't fit as snug, they like sliding on cold rolled steel more than steel nuts. Gaze upon the nuts:

Naturally brass or even hard plastic sleeves would work better but, hey, I have a set of linear bearings on the way($13.50 on ebay) and the plan I'm on will yield me two printers. One will be the one I'm hacking together from crap and the second one will be built with parts printed on the first one and with better hardware.

Anywho! See all 3 axis' working correctly here:

Currently the bed is a cd rom case which amplifies the motor noise in an obnoxious cacophony. I want to use the mirror you see at the beginning as build bed cause thad be coo! However! It's honking heavy.

Expressive mascot:

I suffered an ocular migraine between the fourth and fifth sentence of the post and had to lie down like one dead for about 40 minutes. I listened to George Noory on youtube and laid there in the dark. All is well now tho a bit loopy like always after one of those things.

Friday, February 13, 2015

3d Printer Part 12

I put the motor from a scanner on the slide from a printer. I got my gears and mounted one on a motor to get the bed moving. It works great pulling but it chatters when pushing so I'll be rethinking that. In the latter part of this video, can see the z axis working with slide mounted on it:

My extruder parts came and I mounted them on one of my motors. Please ignore the fact the pictures are blurry or I will destroy you.

Tuesday, February 10, 2015

3d Printer Part 11

The lady from whom I purchased the motors did not get my note to her about wanting the gears for the motors so she didn't include them. I begged her to send them to me and she is going to send them.

I ordered this j-head with teflon tubing today for $21.99 and the gear I need for $1.33. With the motor I got for $8 and the printed parts for the extruder, my total for the bowden extruder/hot end setup is $38.82 which clearly beats getting this one w/no j head and this one including everything.

I'm going with the bowden setup because the motor/extruder combo can be mounted basically anywhere so the z axis motor and the y axis motor doesn't have to move the weight of the extruder. My plan in the future is to add a second extruder so saving the weight now makes sense. Cripe I'm proud of myself! My parents didn't have any kids that lived.

Today, I messed around more with the Pronterface which is.. wait for it.. a printer interface. I don't know why there is a freaking 'o' in there! Anywho! It was stalling because it couldn't find a thermister and I tricked it into going with a 100k resister. Also the motor would stop saying the endstop was triggered. I shorted that sucker out with a jumper! In business!

I probably won't do much on the frame until I get the gears from that motor chic for I am not certain if I'll need timing belt or not. I will know when I get the gears.

I made some pretty good headway. Too bad I don't have pictures or a movie today because it's cool. I'm stoked. The z motors were just buzzing regardless of how I adjusted the amperage. With some reading, I discovered I was trying to push the motors too fast. I have the z axis and x axis moving nicely. 

Sunday, February 8, 2015

3d Printer Part 10

I got my motors I paid $39.99 for

and have already tested them and determined their pinouts. That black thing on the breadboard is an H bridge motor controller and I don't currently know how to limit current on that kind of circuit so that puppy gets wicked hot powering the nema 17.

I also got my Arduino and my RAMPS shield.

I did a couple experiments and got the Arduino to drive the motor. I didn't make a movie because it would be redundant as I've already done the same thing a couple times with gate logic and now I've to done it programmatically. I have to say I found the Arduino IDE pleasant and easy to use and set up. I read about some people complaining about the non brand name Arduinos giving a problem because the serial chip is a cheap CH340G. Even the ebay seller sent me a message reminding me to download the drivers for it which I did. Windows 7 found and installed the drivers by itself. The IDE was able to communicate with it and install the firmware(Marlin). The printer interface software also was able to talk to the firmware just fine. It remains to be see if I will have a problem in the future and if I do then I'll pay the extra 3 bucks for a real Arduino Atmega 2560 and demote this one some future project.

I added some more wood to my frame today so it's starting to look like it will be able do something soon:

I found this scanner in my attic that is so old it has a parallel plug. I will be dismantling it gleefully:

So I have gotten the electronics and the motors. I have also ordered the heated bed for which I paid $7.49.

I have decided to go with a bowden style feeder(which is used in delta printers) so I ordered the printed parts and hardware for it for $7.50.

I'm watching a j-head and an extruder gear.

This is what my work space looks like right now and I thus far spent $83.61:

Thursday, February 5, 2015

3d Printer Part 9

I broke out the drill press so I could make some precise holes in some scrap wood I have. I built a little bed on rails and connected it to the motor using a zip tie as a link. As you can see in the video my pinch roller wasn't pinching enough so it slipped. It occurred to me that whenever I'm building something, I'm always frantically searching for hardware. While I'm out gallivanting around on the morrow, I'll pick a bunch of nuts and bolts and I'll be able to make good brackets and stuff. That will rock.

I used the circuit from my last video to drive this motor but I eliminated one of nte1825's and bumped the voltage up to 12 volts on the remaining one. That made the motor strong enough to move the bed with a spool of solder on it. You view now:

I have some breadboards in route here from China so I can make some reusable modules for my experiments.

Wednesday, February 4, 2015

3d Printer Part 8

I got the teac motor working with my circuit and I bought a grip of ttl chips to play with.


I'm going to have some extra parts I'm not using in the 3d printer so I've been considering other project I can make out of those parts. Maybe a couple persistence of vision projects featuring lasers like a raster and/or vector display or 3d scanner.

Mayhaps my faithful readers can give some suggestions of microcontroller controlled automation projects..

Killing time till my parts get here, I made another circuit with a counter and a demultiplexor(the last one, I made the demultiplexor with NAND gate & AND gates). View it here:

Someone asked this:
"is knowing which bits to print first complicated? or do you just get the printer to start at the bottom and trust your 'plans' will work out ok printed that way?"

Mostly, you just can't print anything horizontal that is hanging in the air without support because there is nothing to squirt the plastic onto. Such as a chair- it would take some planning to print a chair because no matter how you rotate it, there will always be some just hanging in the air. My solution for stuff like that will be to make things in parts like this guy's robots.
I would like to do things like this and a some other ideas.

This is my new current plan: Build this thing with crap around the house and stuff I've ordered and use it to print proper and more precise parts to upgrade it. Then I'll use these parts for some other project like a plotter or CNC thingy featuring a Dremel. I have one of those flex shafts for my Dremel so that should make it easy. I may not get away with not learning g code..

Tuesday, February 3, 2015

3d Printer Part 7

Welp, I ordered the Arduino Atmega 2560 which I got for $10.59 and the RAMPS shield with 5 motor drivers for $18.04. I will now wait as fast as I can until they get here from China.

I believe my plan for now is to make it work with crappy printer motors until I can upgrade them to NEMA 17s like the plans call for. I might order the heated bed today too.

The circuits I made above drive the motor at 5 volts which is not enough to run the motor at full power and speed, but I was being conservative as I'm not really electrically inclined either beyond basic circuits and digital design.

Also, I have discovered in my reading, the traversing bed is the y axis not the x axis.

I found one of my Teac motors from a 5 1/4 floppy drive and know I have at least 2 more- Weee! Also, I remembered I have 4 micro-controllers I could have used to simplify my design- 3 TI Launchpads and a coriduimcorp microcontroller! The reason that is easier is that rather than wiring 2 gates with 6 wires each and hour's work and testing, the logic can be obtained through coding with just a few keystrokes. I was glad I did it the hard way at least once though. That'll give me something to do till China sends me my shiz.

Too bad I don't have any darlington arrays laying around(aside from on that scanner control board that is) My 10 o'clock is right near OEM Parts so I may find myself accidentally shopping for good stuff on the morrow...

Sunday, February 1, 2015

3d Printer Part 6

The image shows a dude not happy with what he has as it is woefully inadequate.

My Dell printer yielded 2 stepper motors and a regular permanent magnate motor and the main slide I want to use has guess which motor mounted to it? That's right. The permanent magnet motor which can't be used in this application. I look upon those printer parts as the Phantom Limb looks at his baby arm.

Thursday, January 29, 2015

3d Printer Part 5

I got my chips to move the motor- gaze upon the magnificence here:

Thanks! Next up for sacrifice to my vanity is this lovely Dell printer/scanner:

See how I rip at its flesh to get to the juicy succulent innards!

I failed to mention the scanner that is forming the base of my 3d printer yielded a nice cold cathode tube and voltage inverter I intend to us as accent lighting. It runs on 12 volts and i have already tested it. No picture yet.. 

3d Printer Part 4

I discovered I have a bunch of 74ls08's laying around and those are AND gates- bonus! That make's it simpler- see my new diagram(just imagine those inverters are not going to be NAND gates hahaha)

Here's what it looks like blinking in sequence as it should(too bad I didn't get the other chip in the picture- whoops):

Maybe tomorrow I'll wire the motor to it.

Monday, January 26, 2015

3d Printer Part 3

I was able to make the motor move by sweeping the wire across 4 leads manually. I wired up a decade counter to do it automatically and added a 16 output multiplexor to change the two binary outputs to four lines going to two NTE1825 motor drivers(these are meant to be used as H-bridges so don't tell anyone of my perverted use for them)

Stupid me- I forgot the 74ls154 outputs an inverted value so I have to invert every output which I did tying the 2 inputs of NAND gates(I have a buttload of these 74ls00 chips) together to make an inverter.

Sadly my multiplexor is not working right so I need to make a multiplexor from NAND gates. Here's what that would look like:

Yeah, I'm not doing that. From my swiggles one can see I will need 12 gates to get it done. That's 3 chips all wired up for a proof of concept experiment that is unneeded because I've already proven I can move the motor using the sequence I did. Bah, be gone with it!

Note to self:

Thursday, January 22, 2015

3d Printer Part 2

I had not grounded pin 1 on the 555 is why it wasn't working. The following gif is a simulation of what it looks like working:

I took a picture of it on and one of it off and since I had to touch the camera the image moved. I edited the rest of the image out with an opaque mask but didn't align the two images positionally. That's why the gif looks like universe warps around the lit led. The real circuit is flashing about twice as fast as it is simulated here. The rate can be changed by fiddling with the resisters and/or capacitor. The is a formula one can use to maintain tight control but I don't need it for what I'm doing. I wish I owned an oscilloscope- then I could be one of the cool kids.

I'm powering this stuff with an atx power supply. Red wires have 5v+. Ground out the green one and the power supply gets turned on- oo la la!

This is the circuit I'm using minus the led connected to vcc.

Notes to self:

A+ = Black
Acom = Red
A- = Brown
B+ = Yellow
Bcom = Blue
B- = Orange

Wednesday, January 21, 2015

3d Printer Part 1

I am going to build 3d printer for a cheap as I can.

The posting is meant to document my progress and keep me focused and motivated.

In holiday season, I'm always slow because people don't get their crap repaired when they're busy buying new crap. Consequently, I'm broke right now so some forward movement will require waiting on me to get out of this financial hole. I was wanting to buy a 3d printer outright all built, but for a few reasons(besides brokenness) I'm going to build one. I read a few books and watched a documentary on the subject and his dude's instructable convinced me I could adapt current open source firmware and supporting software to any Cartesian printer as the g code language never changes. The printers are surprisingly simple in what they do..

To begin I dug around in the garage and found a scanner I have knowing the travel will be pretty long. Too bad I've thrown away a zillion printers and scanners in the last year- doof. Here it is sans lid with some of the guts removed:

And here is how I am going to use it with the scanner's glass as a traversing build bed-. I believe that to be the x axis.

I can't order the computer yet but I can mess with the motor and of course that is more complicated than just plugging two wires in. The motor in the scanner and all of the other motors I'll be using are stepper motors so they require some orchestration. Right now I'm making a pulsing circuit from a 555 timer as I have done many times but this one isn't working:

Once I get the pulsing circuit working, I'll figure out the pin outs and sequence to drive the motor and run it on a ttl counter. The final project won't need all those shennigans as stepper motor drivers will be mounted right on the RAMPS Arduino shield.

Monday, February 17, 2014