A Question from RepRap Forums

Earlier today, I was asked on the RepRap Forums why I wanted to know if anyone had had any success with printed timing belts or something similar. Well, there really is no one major reason as to why I am doing this, there are several: to make things just a bit easier in terms of sourcing the materials, to keep to the philosophy of a getting closer to a completely self replicating machine, to keep costs down, to make it easier to replace, and so on. Pick any reason you want.
I have heard that this particular part is a bit hard to source in some areas so I decided to find some sort of alternative to it. However, this is only something that I am considering. This may change by the time I release my complete design. It all depends on what is the most readily available and what is then the easiest. I have not heard anything to suggest that this is a part that needs to be replaced often so it is not as if there is a desperate need to keep many on hand in case one breaks. I am simply trying to keep my options open.

Day 30: Another Draft

In keeping with the promise I made the other day, here is the first draft of the top plate. Again, not sure if I want to have a bolt that will attach the arms or if I want to have the ends of the arm connect to a printed piece. Ultimately, it will come down to what creates the smoothest movement. Right now, I'm leaning towards a smooth rod fitted into each diagonal for the four arms.

Update (5:36 pm): Here's the first draft of one segment of the arms.

Day 29: First Drafts and an Update

Okay, so this first draft is pretty awful and incomplete but I promised to post something and I am.

The design is pretty general and looks like every other delta bot out there pretty much. The arms each have two points of articulation for a grand total of 16 printed pieces not including the pulleys that will be attached between the two rods that make up each arm. The extruder carriage is pretty basic as well. This is mostly because I can't decide what kind of attachment I want.
The motor for the extruder may be mounted on the extruder and hot end or it may be mounted to the side. It really depends on the weight of the motor, which, if there are any RepRap forum readers here that have seen my thread, will either be the standard Nema 17s or 23s. Again, this all depends on how much weight the printed arms can handle since I really want to keep this area as light as possible. There are so many options for this that I really won't know what I like for this project until I start building.
This morning, I ordered new motors for my mendel so, hopefully, I can start printing by Monday or Tuesday, depending on when my post arrives and assuming that the motors work.
I have also decided that there will be some lower priced perks:
-Printed parts only- This is for those of you that would like to source your own materials. This includes only the printed parts and fasteners. The price for this will likely be in the $50- $75 range and will account for the cost of printing materials.
- Printed parts files- This will be the lowest option and will be a $25 donation for which you will recieve the .stl files to print out your own parts.

More crazy updates!

Okay, so, first things first, I have to say, I can never finish a proper mechanical drawing. I have a love hate relationship with them. I love mechanical drawing and surveying (God only knows why) in an archaeological setting. Not so much with the engineering. Why, you ask? I can't draw mechanical parts to save my life. Fashion drawing? Fine. Biological drawings? Pretty passable if given enough time. Anything math or engineering related and I will make your pre-schooler look like Picasso. Ask any of my grad professors who have had to deal with my intensely poor perspective drawings and freehand graphing. It's pretty frightening. My solution? 2D Mechanical drawing software! I'm still trying to get a grip on it and it's features but it has to be better than my poor attempt at sketching out the axis rods for the printer. Hell, I can't even figure out what I meant to draw last night by the picture alone. Thank God for my scribbled notes that weren't smeared with spilled cabernet. I'll be posting the first draft of the framework tonight and possibly the draft of the rod. Why is it taking so long? I can't decide if I should leave the rods unadorned, a la Rostock, ou give them some kind of subtle embellishment.

Also, I haven't been able to start printing because of an issue with my motors. I'll be giving it another shot tonight and if I still am not getting any results, I'll be returning my motors and it'll be another week or so before I can start printing. Disheartening, I know. Either way, at least I'm getting work on this project done.

For anyone that read my previous posts, the sweet little homeless stranger that was brought into my home is still here. She went to the vet on Saturday and everything checked out just fine except that she was still lactating from a litter of kittens she had had fairly recently. She's cranky but a sweet little darling that has been sitting with me while I work on drawings today. However, she seems to think that the cables on the Mendel are for chewing and pouncing. Oh well.

Here's the new software I've been using:
Solid Edge 2D Drafting

More setbacks

Well, it looks like it probably wasn't bad stepper drivers but may actually be the motors that just plain don't work. I've tried everything and nothing can get the damn things to turn. I've tried contacting the person who I bought the motors from and am still waiting for their reply. On another note, the hot end that I bought pre-assembled just fell apart on me. It looks like I'll have to disassemble that to replace the thermistor and double check the wiring. I had been wondering why the hot end simply would not heat up and upon emailing the seller, recieved a rather rude response of: trace the wires. Well I guess I never would have thought of that! Because that wasn't the first thing I did when hooking it up to the PCB to begin with.

My frustration with the motor wiring has begun to affect my boyfriend and set him in a horrible mood on more than one occassion. I have the feeling that perhaps I should have just contacted someone with a working printer to print out the parts for me as this is proving to be a ridiculous hassle.

Day 24: A much needed break

Okay, I seriously had to take a break from this to get my head sorted. I came away with one really important thing: before going insane and rewiring everything because something doesn't work, check that everything is there. How did I come to this mind-blowing notion? I took a break, stepped back and double checked my mendel only to notice that I had forgotten to put the stepper drivers on the PCB and that was causing my motor issues. It only took nearly a week of Adderall-fueled rage and confusion to figure this out.

So what has happened in the couple of days I took off? Not much except for my significant other's frantic call to me yesterday to say that there was a tiny stray kitty two blocks away that he needed to rescue. Other than that good deed, I have some (really) rough sketches of some of the components for the delta bot. Tonight, I plan to finalize the sketches into something actually resembling parts and not a bracket with a face. Let's wish me luck on my first attempt to create an .stl file!

Here are the part(s) I'll be working on tonight:
- arm segments
- Extruder carriage (although I have seen a number of really nice designs already being used)

I'm really interested in trying to find an adapted, printable version of the timing belt. I've seen this discussed on the RepRap forum and am really interested in people's efforts to get around this part of the machine. So here's my weekend quest: Find a suitable replacement for the timing belt or some sort of adaptation of it. This is tough since you can't really print a timing belt in ABS. Well, you can, but it wouldn't exactly function the way it would normally. I guess it would be more akin to a track than a belt but whatever.

Happy weekend, readers!

Update: Prototype design teaser

Here's a whole bunch of design teasers to hold everyone over until I can post pictures of the first group of printed pieces:

- It will be a delta robot since I want to offer a large print space.

- Roughly 50-75% of the parts will be printed. <-- This may bring the final cost down if I can find a good supplier of ABS.

- The print envelope will likely be at the very least 8"x12"x 20".

- Electronics will be mounted on the rear of the unit.

Day 21

After turning to the lovely people on the RepRap forum, I think I have a pretty good idea of where I'm going. Also, the power supply issue of yesterday has been solved thanks to a handy plug I pulled from my HP Desktop printer. Pretty sure that drama was mostly the result of my sitting here staring at wires all day and trying to make things much harder than they had to be.

So here's my plan for today: Start printing, damn it! Other than that, I was able to get down some quick ideas before I completely lost my train of thought while watching Hardcore Pawn and listening to FX's truly ridiculous DVD on TV version of what I'm assuming to be a good movie. If all goes well today, I should have, at the very least, the connecting portions printed for my prototype.

Still no name for my prototype. Hell, Still no name for my project, really. Hmm. Suggestions are greatly appreciated.

I also want to say that with the new school term starting, I probably won't be getting as much time to dedicate to my project as I would like depending on what the workload is like. All this means is that: a) I will be spending equal time between classwork and my project, or b) I'll be spending the same amount of time on my project but with the added time of schoolwork tacked on and kiss sleep goodbye.

One step ahead- Upgrades

So, while thinking about this prototype, and how to make it about 20% cooler (If you got that reference, good for you), I've been thinking about what possible upgrades I can include in the future. If, in the process of building the initial prototype a few of them get sucked in, all the better.
- Dual or triple nozzle for adding different colours. I haven't found a nozzle for this yet and seriously, how big would the extruder be if there were three of them? eep!.
- Pellets instead of filament- Really just haven't had the chance to give this a lot of thought, yet.
- recycled material- this has been done by a group of people as an ingenious way of building one of those milk carton rafts.

Day 20: Can we please start printing already?

So, this weekend? Total bust. Instead of working and trying to post a new update about, well, anything, I spent the weekend wondering just how much about differential equations and Natural Language Processing I'd forgotten in the months since I last took any classes and going to exhibits about the Terracotta Warriors and the history of espionage to appease my anthropologist soul.

Today, I am determined to end my confusion about the best( and easiest) power supply for my mendel so that I can finally start printing something. While printing the pieces for my still as yet unnamed prototype is at least a week away, I will be printing replacement Mendel parts if anyone is interested.

After peeking around on the internet at some truly neat delta robots, I'm condisering adding the more fluid(? not sure if that makes any sense to anyone not me) movement of the Delta robots I had seen on Hack A Day. This option also seems to free up a lot of space so that, if you wanted to watch it print, there is a greater viewing area, as well as taking care of some of the clutter that other frames seem to have.

Day 15: Some stuff broke

I may have slightly busted up my Prusa Mendel before I could even start printing my prorotype. I guess we'll find out how my duct tape fix-it has helped once I start the printing process on Friday, hopefully. I've gotten a bit sidetracked from designing the parts for my prototype by building the Mendel and looking at cool things to print out (a Batmobile was suggested by SOMEONE) and designing the casing for a robot that was temporarily moth-balled.

So here's what I've been working on: determining the print envelope size, part sourcing, determining the final size including casing.

Day 17: Software Issues, Educational packets and Cat Toys

After attempting to install the RepRap Host software with no success, I've gone with ReplicatorG. As not everything is wired and connected yet, I haven't been able to test the printing capabilities of this programme. No biggie, just another delay. Cue the throwing of high heels around my work space. Joy. I've been fiddling around with the software and I've pretty much decided that this will be the software I will include with the kits. Of course, you don't have to use it but until I come across something I like more, I'll be using ReplicatorG.

I've begun outlining what will be included in the educational packs that come with the classroom kits. Besides the obvious assembly manual, I will also include a list of recent articles about 3D printing and what it's being used for (Legally I cannot distribute the actual articles without permission from the author(s). If I manage to get their permission, I will include the acutal article and not just a link.), worksheets on electrical componenets and how they are being used in the machine, ideas on how the printer can be used to supplement traditional learning, and some other items. I will also be giving you the option of having the materials on a thumbdrive or in print. The default, for environmental reasons, will be a digital copy.

On a completely, although still slightly related note, my cats, Jack and Peanut, have decided that the print bed is a delightful place to lay their heads and that timing belts make excellent chew toys.

Who Doesn't Love Free Stuff? or Pay It Forward

Sorry it's taken me so long to finally get around to posting this.

The whole mission of this project is to encourage hands-on learning and creativity. That being said, what could be a better way of promoting the this idea than by giving away a few free printers?

Here's the catch: I will only be giving units to teachers who are nominated since this is primarily an education project. You can nominate yourself or a friend or a well deserving teacher. Depending on how many people are nominated and how many units are purchased through donations, I will determine how many free printers are given away. The cost to produce these free units is included in all (except the basic model) donations. So, the more units people buy, the more I will be donating. Of course, not everyone nominated will recieve a unit. The winners of the free units will be chosen based on why you think they (or you, if you are nominating yourself)deserve a 3d printing kit. Just leave a comment with the individual's name, school they teach at, and your reason why. I'll be choosing the recipients sometime in October.

What will you recieve? I haven't made a final decision as this will also be determined by how well funded this project is so let everyone know about it! It will most likely be a mid-range version of the classroom kits with a laser scanner and a full complement of teaching materials.

Day 13: Radio Shack saves the day?

Many people know of my grudge-filled love/hate relationship with Radio Shack. I like that there is one a block and a half from my apartment but I hate their selection, the general ignornance of the products they carry and their uber-inflated prices. For example: I needed 80-something IR LEDS, they charge $2.19 for ONE IR LED. Seriously. I found a 100 pack on another website, for under $5. I know, right?
Another example: I walk in for a desoldering vaccuum the other day and the sales person asks me if I knew what it was for when my entire purchase was soldering accessories. Granted, not the worst experience but every time I go in there I get questioned about whether or not I know what hte products I am purchasing are. And it's always the same sales person. Maybe it's because I'm a woman and the last time I was in the store I was talking to another sales person about the plight of finding a good (ie. space saving yet still roomy enough to pack full of goodies) computer case for a decent price and this guy started questioning whether or not I acutally knew what I was talking about.
But i digress, I left with a happy little haul of a new desoldering vaccuum, soldering tip, and a new usb cable (mine are always vanishing) only to realise that, in a Benadryl fueled haze, I had melted the little prongs off of my FTDI chip. Joy. Now I have to desolder the sucker, buy a new chip, clean up the board and solder the new chip. I had purchased an extra Sanguinololu board to build and then resell but I guess that one might not be sold as quickly as I had hoped but will get a very thorough testing.

EDIT:In my rush to get my stuff, I overlooked the desoldering vaccuum below which is even better priced (I paid $14.99 for mine) than the one I had bought.