Good Morning All,
I have decided to start off using an Arduino Mega-2560 with a RAMPS 1.4 Shield for the first iteration. Here is a picture of the progress so far. Ignore the resistors in the picture. I thought I needed them to use the Arduino control signals but as it turns out the larger drivers can use the 5v Arduino logic without any pull up resistors.

Stay Tuned.....

 

Just out of curiosity...Has any one ever taken an old USB memory card reader out of an old AT style computer and tried to get it to play with an Arduino???

 

Chirp..Chirp...

I guess I will take that as a no.

Boo and I made some good progress today. We took an old ATx power supply apart and gutted the wiring then modified the connections so it will work without the motherboard. We also changed the top plate arrangement a little so it would fit. Tomorrow should see almost all of the top plate wiring finished. Getting close to the first moves

Stay Tuned....

 

LOL with all the commotions even Lord Zulu seems to have taken an interest in our project. He jumped down from his perch to do a personal inspection.

 

Hi All,

Another good day today. I built my shielded signal cables and got them installed as well as the wiring for the optical switches. I am just about ready to put the v-slot back in and start on building the carriage plates and effector arms...

Stay Tuned...

 

Hi Bob,
Boo had a lot going on yesterday...but I showed him a copy of the engineering change notice and he gave me a verbal bark of approval and promised to make it official with a follow up e-mail which was in my inbox this morning . I'm still trying to figure out how he gets the emails out so fast with no thumbs

 

s

Good Morning John,
Thanks for all the encouragement. Basically an ATx or AT standard power supply is a simple switched mode PSU with a lot of outputs off a set of common rails or connection points combined with a few simple control circuits. Reprap.Org on Wiki has a good article for repurposing them for other applications.

http://reprap.org/wiki/PCPowerSupply

Thanks for the link on the SD ramps. I know the SD card reader for the Arduino is cheap I was just curious if it would be a simple plug in with a USB host controller shield added to the stack which would also give me more options for hooking up more stuff

 

Hi All,
Boo and I have been working hard...

I managed to get the shop all cleaned and swept again after another furious flurry of flying fur this week. I also spent some time going through the old PC that kindly donated its internal organs to our cause and pulled a nice CPU fan that runs on 12VDC and even includes a tachometer output and PWM input for speed control. I also took some pieces from the frame and made a stand off to hold it over the RAMPS board to cool it. I didn't hook up the tach or pwm in, so it will always run full speed while power is on. If its too much air or noise I may add in a low power and standby mode later. And as a bonus it came with a 3/4 pound aluminum heat sink that might just find itself participating in a combined multi-color single screw extruder and hot end experiment. But to start with I will be using the Bowden extruder and Excalibur style hot end.

Well after his inspection Lord Zulu has given us leave to carry on and returned to his other lordly endeavors. Of course Boo is getting excited now that all the wires are hooked up and ready for a smoke check. He even asked if he could stand by on the extinguisher

Lot's more to come, Stay Tuned...

 

Hey Folks,
Could not wait to share this. I decided to take a look at the big heat sink that came out of the old computer to start thinking about how I might use it in the future.....Wellllll....It practically jumped onto the robot! I couldn't believe how well it fit the baseplate on the router motor I picked up. And it's solid as a rock, I guess I am just going to have to use it sooner, rather than later LOL....I just love it when things pretty much build themselves.

 

Hey Mark,
The heat sink has become the starting base for my hot end for 3D printing. For the first iteration I won't be trying anything too fancy...basically I will just drill a hole through the middle and tap some threads for the Teflon tube quick connect on one side and then tap the other side to screw in the tip and heater assembly. I was going to start with an Excalibur type hot end but then I would have to build an adapter and figure out how to mount it, etc....

All I had to do with the one out of the computer was line it up to center and drill four small holes for the backing plate and I can be sure that it's compatible with whatever I use to mount the router because the delrin plate came right off the bottom of the cast casing for it

 

Good Morning All,
Thought I would post a few pics showing the progress on the tool head. Every thing seems to be coming together nicely.
My brother Shaun usually stops by on Sundays and today was no exception. Of course, as I was explaining how the framing system should work Boo just couldn't resist pointing out all the things he helped with

Stay Tuned....

 

Hi John,
Thanks again, Like I said, it practically built itself. I will still have to do a few mods to get the effector mounts exactly where they need to be but I don't think it will take much to get the mounting blocks incorporated.

And I am definitely looking for more flow from my hot end than your average 3d printer if I can make it happen. I plan on running 3mm filament and I will be using 3 ceramic heater cartridges at the hot end tip to melt it as fast as possible while that big heat sink keeps the melt zone as short as we can get it back from the tip. I will probably have to go with a min .5mm nozzle and maybe bigger if I can get the nema 23s spun up to high speed for plastic mode. With the current transmission running the motors at 1000 rpms would give me app 850 mms at the effector.

Changing between tools should be extremely easy. Right now to remove the router motor it only takes releasing a clamp and unscrewing it from the base. To put the hot end on takes just three small hex head machine bolts and a couple quick connections on the top. Of course the working beds will be different too...but I have a nice idea to make it modular also.

Springs in between the effector arms is the traditional method for reducing lash in parallel type bots. The hardware store around the corner from me has a good selection of heavy duty ones that would be about the right size and would probably make due for getting started. I also might look at exploring a different method depending on a lot of factors.

Stay Tuned...

 

He would have given me two thumbs up but he doesn't have any

 

Good Morning All,
I have been waiting on some parts for the frame...so I decided to get some work done on the hot end. It's still a work in progress but I am liking this layout ATM. I will have to shorten it up a little and come up with a shroud for air flow but it is definitely getting there
I owe John another big Thank You for the extruder parts and an apology to Wade for mixing him up with Mr. Bowden since what I have is a Wades Geared Extruder and not a Bowden. Sorry for the confusion folks.

 

Hi All,
Thanks Mark. Still lots of work to do but I enjoy the challenges that comes with doing something completely out of the box

The hot end is nearing completion. I got the new extruder mount done and it looks like I will not use the router base to hold the hot end since the Nema 17 motor on the extruder sticks out too far and I don't want to start cutting up the router base to make it fit. No big deal since they still will both mount using the same 3 hole pattern. One concern I have with printing really large items is extruder speeds. I have heard the hobbed bolt has a tendency to strip the filament at high lay down rates or if the head is accelerated too fast from a dead stop. Soooo.... I figured while I was at it I would try a new idea for the filament feeder. Basically what I did was file out the bolt where the filament contacts it and installed two rubber O rings to see if I can get some fast feeds without the risk of stripping the filament. Haven't seen anything like this but before I claim it for my own, I would like to know if anyone else has seen anything like it??? If not I am calling it Brian's Rubber Baby Buggy Bumpers...so I can chuckle every time someone has to cite it for attribution.

 

Thanks Tweakie

 

Hi Bob,
Boo says I can do all experiments I want as long as I have a fall back position. In this case, if the O ring idea flops I can just replace the bolt with one that is hobbed like the original design calls for. Slippage would definitely be a killer. I don't think I will have to worry about the hot end getting too cold, but if it is an issue I might also look at a hybrid design with two O rings, one each placed in a groove on either side of a hobbed notch.

 

Hi Yetiman,
I am sad to say that I did not make much progress last week at all. I managed to snap my tap while hobbing a bolt for the extruder, so that brought my hot end build to a slow crawl. I ordered two new taps and they should be here in the next day or so. I am also waiting on a few parts for the frame that I need to proceed to the next steps. I have taken some of the time to update my drawings and I have been toying with the idea of a stackable form for the frame that I am working on today. If Boo and I can make some progress on it I will post up some pics later.

The suspense is killing me too.... Stay Tuned...

 

Hey Guys,
I haven't abandoned you. I have been working on finishing up the forms and prepping for the pour. Here is a picture of the bottom section which is nearing completion. I am working on setting up the video camera to document the process live and in color when the forms and concrete come together. More pics to come as I make progress.

Stay Tuned...