Why NOT to buy a clonedel

For the uninitiated, a clonedel is a set of molds with which you can cast a reprap with polyester resin. It made a big splash in the reprap circles when it first came out, but Clonedels have really died off in popularity since then. I know why. It seems like a great idea. It can theoretically produce an entire set in an hour or so, and the material cost is significantly cheaper as well.

Unfortunately, clonedel is only a good idea in theory. I bought my clonedel set for $50 when printed prusa kits were $80-$120. Then I had to drill all of the pieces out, sand pieces flat, cut off the mold lines, and deal with missing pieces in my kit. Oh, I also forgot to mention that my parts ended up coming in a fruity flavored assortment of colors that looks pretty hideous.

The thing that really put me over the edge is that the parts just aren’t strong enough. My x-axis motor mount is now flexible enough that the motor shaft isn’t perpendicular to the belt, and my prusa hasn’t printed a single thing yet! In the top view you can see how far off the belt is deflected, and the side view is just for fun. Is there anyone out there who can print me both x axis parts? Pretty please? Those are the only two big parts that I haven’t replaced, and There is no way I can print their replacements with the belt constantly slipping off of the motor.

After a fair bit of thinking, I have changed my stance on how people should build their first reprap. Unless you have a strong community around you. I really think that a kit is the best idea for your first machine. Provided you buy it from a reputable vendor (I like makergear) then you should get all of the parts you need and support to help you get it together. Then feel free to self source your second one!

Go buy a Makerbot Grab bag!

I don’t remember who tweeted it, but I saw a tweet a week or so ago saying that the makerbot grab bags were a good deal. I looked at them and bought three. I figured that at $9 each they would be a good deal.
even if they had nothing but the ftdi cable.
I got my box today and Wow!

I got two of the grab bag #1 and one #2. Each of the #1’s had TWO ftdi cables, two early nozzles, 5 pfte barrels, 2 brass barrels, a bunch of thermistors, pulleys, a fan, and some plastic build plates. They said that the grab bag could or could not include those items, but I didn’t think it would come close to having them all!

The second grab bag was similarly stocked, with a ton of pulleys, belts, some rods, some wooden build platforms and a ton of fasteners and plastic bearings.

They said it in the description, but I want to reiterate it: If you are a cupcake operator, you should probably get this. It is a great source of spare parts that would have cost you hundreds to buy a few weeks ago from makerbot. It will hopefully keep your bot printing for a long time to come.

If you are not a cupcake operator: it’s still a damn good deal.

Thanks makerbot!

mini free-day @ sparkfun?

The other day I saw a tweet from sparkle labs saying that they were ‘participating’ in American Express small business saturday. The jist of that event is that Amex will give you a $25 statement credit if you register your card on their sbs site and then use it to buy more than $25 from a small business on November 26th.

I did a little sleuthing and it seems like Sparkfun also qualifies. They show up on the sbs page in a search for Boulder, CO. There is no sure-fire way of knowing if it will work, but all signs point to yes.
If you want to give it a shot, be sure to actually register your card on their site, buy some stuff, and have (spark)fun supporting small businesses!

Please note: This has nothing to do with sparkfun themselves, and I doubt they even know about the programs existence. Don’t bug them with questions. Call up Amex if you want to ask someone. Either way you end up with cool stuff. One way you get a $25 credit for buying it. Oh yeah, it also seems like you can get the credit for every Amex card you have with them that you register(!)

Reprap Prusa: pushing plastic, almost ready to roll!

Here’s an overview shot of the prusa, E-stop switch, and macbook. I still have to build the bed, but the rest is all there. Yesterday I flashed it with the sprinter firmware and I like it so far! The biggest thing is that it has acceleration. That enables lower torque motors to start slow and ramp up faster over time. I also installed pronterface, because replicatorg has been very buggy with my prusa. One quirk is that the default z-axis speed is set to 200mm/minute. That was way too fast for my 80oz/in motors. Perhaps with a slow acceleration curve they might get up to that. I cut it down to 100 and they were much happier.
Continue reading “Reprap Prusa: pushing plastic, almost ready to roll!”

Prusa Update

It’s been a busy start to the summer! I was able to go to Maker Faire, and now that I’m back I’ve spent every spare second on my bike or at the new hackerspace in town. One benefit of being a hackerspace member is that I finally have a place to keep my big /noisy / messy projects!

Here’s a pic of where it stands right now. I have everything together, but it’s not wired up yet. I’m also replacing the clonedel parts as fast as I can. They are causing more trouble than they are worth right now.
Here’s a link to solid state depot’s wiki on my prusa.

Here’s a pic of my monster e-stop button. It came out of a printing press. It is wildly overkill, but it looks cool. It is currently wired up to the psu, so if the switch is tripped, it cuts power to the machine. dead stop.

I’ll update more when I do more. I’ve been learning how to use a lathe in order to drill out some hot ends. It’s been exciting so far…

super easy measuring rod

rulers are nice, but when you want to tell the difference between 470mm and 469mm, there is no better way than with a stick that is 469mm long.

The reprap build instructions suggest you cut some sticks of precise lengths in order to verify that your threaded rod lengths are exact when the frame is all bolted together. That is a good idea, but it seemed like a little too much effort. What I did was to use the last threaded rod from the reprap build. Before I installed it, I put two nuts on with a washer in between. Now I can move the washer to whatever length I need to measure and I can stick it between two vertexes. It’s less steps, and it already uses parts that you have!

completely unsorted reflections on building a clonedel

1) Last weekend I completed drilling out my clondel kit and started bolting things together. Here’s a list of things I realized.

2) Having precisely cut threaded rods is nice, but not necessary provided they are longer than spec.

3) Drilling out the metrix createspace clonedel kit is difficult verging on impossible to do exactly. The vertex pieces that require precision don’t have flat, 90 degree sides. Also, some of my pieces varied +- 3mm in thickness. That is a big problem when the piece is 15mm thick, and it’s off in the – direction. I had to do a fair bit of eyeballing on those undersized pieces or else the drill bit would have just ripped through one side. This kit is a lot better than nothing, but the first thing to print is definitely replacement pieces. I also think I have one of their earlier versions judging by the way my z motor brackets look, so potentially they have improved since the first few batches.

4) I scavenged some 8mm rod from two desktop printers. That gave me enough for the z and the y axis. To get the long rods needed for the x axis I think I will probably need 2 more printers to destroy. I’ve been toying with looking into the rods from ikea filing cabinets to see if they are even vaguely straight or consistent. I doubt it.

5) Looking at the printers made me wonder if dc motors could be used with opto-encoders for this project as a replacement for the steppers. I’m not sure what would be the best way to do it, but I’m considering making a “stepper driver board” out of an arduino to see if I can get it to behave as a drop in replacement.

6) It appears like the thin and thick sheet are unnecessary for a prusa. Well that’s nice.

7) I’m looking into using my xylotex 3 axis kit as the stepper interface for this prusa. I think that just means I need to put the mosfets, end stop pins, and thermistor circuits on a shield for my mega and I ought to be good to go.

Nema 17 on the left, Nema 23 (with 260 oz/in of torque) on the right
8) I’ve got 3 nema 23 260 oz/in steppers that would be delightfully overkill for this. I’m wondering if it is worth the trouble of building new brackets for everything. I know that torque does not necessarily equal speed, but I would like to see how fast those would print. I would try the extruder (possibly) and the x and y with those monsters. The z axis doesn’t need that kind of speed.

9) I ended up buying some 8mm linear ball bearings from ebay. 12 for $15 isn’t too bad considering they will last a lot longer than the pla.

10) Using the testing setup of repg from Ben Jackson I have been able to connect to a mega 1280 and a 328. I can’t do much else before it crashes, but at least its a start. Repsnapper seems to work flawlessly with the 1280, untested on the 328.

A Makerbot disaster struck!

I’m not sure what’s been going on with my makerbot, but I don’t like the way it has been progressing! All week long I have been having trouble with my extruder board. I’ve been talking with Matt at Makerbot and he has been super helpful, but we haven’t figured it out yet. It will give me the dreaded “toolhead 0 : not found” error, and once finally connected it will “get tired” mid print and stop heating.

Well… today it stopped heating the extruder tip while printing, then it snagged on the print, bent the brass tube, and the hot end snapped off of the mount with a little flourish!

broken makerbot hot end

I’m going to try to find the drawings for the plastic mount piece that broke. Thankfully that ought to be easy enough to make by hand. After that I have to say I’m at a loss as for what I can do to prevent this from happening again. This is why they call it DIY. I just wish sometimes it was more “doing”, and less “yourself”.

$10 DIY Makerbot filament spool

I can’t believe it took this long, but I finally had a bad filament tangle last week, and a few aborted prints because my old setup wasn’t working. I really needed to get my filament spooled so that it would nicely dispense, and not jam, tangle, or unspool.

I really love the way the official makerbot kit looks, and I bet it really works smoothly. I just don’t have $90 sitting around. I’ve already spent that on ABS, relays, arduinos, and prusa parts!

I went down to the old Home Depot and picked up a cheap ($8) extension cord spool and a few feet of nylon water tubing. My extruder hasn’t had any trouble with its grip, so this creation has the extruder just pull the filament off the spool. I drilled out the handle and carefully spooled the ABS on the spool. THAT took a while, but it’s way better than having to constantly babysit the machine.

Continue reading “$10 DIY Makerbot filament spool”

Help me hack the Belkin Conserve

Howdy internets!

I love the idea of being able to safely switch ac power from a microcontroller. There are products like the powerSwitch tail from sparkfun that easily do this job, but I like to try to be as cheap as possible, so I’m trying to do it for half the price with the Belkin Conserve. This seems like it is just a relay built into a wall wart that is only activate for a pre-selected amount of time. Ideally it helps you reduce your energy use by only charging your phone for say, 3 hours, or by turning off your tv after you fall asleep.

I bought one thinking the relay was probably powered by a dc voltage, and then that I could activate it with a pin from the arduino. Maybe I would have to put in a mosfet or an opto isolator, but it wouldn’t be too hard. After opening it up, I realized that it was all AC and I’m at the limit of my knowledge. I don’t want to zap anyone or any thing, so I’m asking the internet as a whole: what can I do with this?

Here is a closeup of the front of the board,

Here is a closeup of the back of the board.

If anyone has any ideas on how to safely trip the relay from a microcontroller pin I would love to hear about it. If not, then maybe I’ll just let it do what it was intended to do. And then go buy the powerswitch tail.