3d printed metal bike lugs!

This is the convergence of all of my interests: bikes, 3d printing and shiny things!

I saw it featured over on Hackaday, but it’s just too good to not repost.

This is a bike built up from carbon fiber rods and laser-sintered metallic lugs. There is a whole lot of awesome in that sentence. I’m surprised that it looks like it somehow prints with support and requires a ton of cleanup, but it is 105% awesome regardless.

Here’s the vid.

VRZ 1. a tack bike frame with 3d printed lugs from Ralf Holleis on Vimeo.

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Nail Files – Reprap tools list

I’ll admit it. I went into cvs and walked out with two packages of nail files and a snapple. What of it?

Despite the weird looks from cashiers, nail files are absolutely _perfect_ for cleaning up prints. You can do fine sanding, clean up seams, or round off those sharp corners from a kapton heated bed. The best thing? It’s less than $2 for a pack of ten. Pick them up with your groceries, or use them as a cart stuffer on amazon so you can get up over the $25 minimum for free shipping.

Wow, most of them on amazon are a bad deal, but you can pick up a gross of them for $9 with free shipping!

reprap tools shopping list – Irwin self-adjusting wire strippers.

reprap tools - self adjusting wire stripper
I’m really excited about some tools I have found recently, so I figured I would start a recurring series of posts about them. There will be some simple cheap ones, and some expensive ones. Hopefully they are useful to someone else!

If you want a sneak peek, then you can check out the amazon list I made.

Here is the first review: keep your eyes peeled for more!

Irwin Industrial self-adjusting wire strippers.

You can certainly get good results with a traditional wire stripper, but this is faster and can be done one-handed and in awkward situations. Once I unwrapped it, I ran around the house looking for wires to strip (not always a good idea) and happily found a few solid core and stranded wires. This stripper was like magic. You can set a depth stop or you can eyeball how much wire you would like to strip. It has a simple cutter (probably better for solid core) as well as a few crimpers built into the handle. The plastic covers on the steel handle really give the tool a solid feel in your hand.

The best thing is that this is roughly the same price as a good quality pair of traditional wire strippers. I got mine from amazon for about $16, and you may be able to do better off by shopping around. If you do see them in-store, pick them up and feel them. It is a solidly built tool.


I think the usefulness of this is obvious, but it will assist you in doing all of the wiring for your reprap. Your motors, endstops, power cables, heated bed, extruders and thermistors all need to be stripped / cabled and attached to your electronics. It is super useful beyond the reprap as well. Automotive, audio video, and home electrical all are made easier with this.

One last note: If you do end up getting this from amazon, then definitely browse through the rest of my reprap tools list. You might get that cart-filler to become eligible for free shipping, or you might find something that will knock your socks off.

Why Kapton rocks

I have never been a big believer in using kapton tape as a heated bed surface. I never saw much benefit, and whenever I used it I ended up cutting it or scratching it very easily trying to get the parts off.

When I use blue tape I generally heat the bed up to 90-110. I print the part, and then as soon as it is finished I pry it off with a chisel. This ends up with a lot of damage to the blue tape, but it is pretty cheap to replace, and easy to pull up a single strip at a time.

The turning point for me came when I tried to do the same procedure on my kapton bed. The adhesive simply wasn’t strong enough to keep the tape on the bed and it ended up bending and lifting and tearing. I knew that was not supposed to happen, so I stopped and looked at what I was doing, and realized that the point of kapton is that it loses grip as it cools. That means you need to cool the bed in order to get the part off! I feel silly admitting that it took me so long to see I was being impatient.

Now that I have that figured out I print, cool, and then generally I can snap the piece off fairly easily. I wipe the surface down with nail polish remover on a cotton ball before every print. Sometimes I still need to get the chisel out and put the tip under one edge of the piece, but once one corner pops free, the whole piece is free. No more prying from every corner.

My one complaint is that I only have 1″ wide kapton. 2 or 3″ would be much nicer. I’ve also been meaning to get some PET tape with a high temp adhesive to test against.

Ways i have messed up reprap prints

This is a running list of all of the ways I have broken a print. This doesn’t have anything to do with my machine calibration. That’s a whole other post in itself!

-I got a snag in the filament feed which stopped extrusion.
-My heated bed shorted out on a bulldog clip.
-With the print not centered on bed it hit the endstop a few hours into the print.
-I have tried to print from stls not positioned at z-0.
-My cooling fan for extruder unplugged midway through and then the extruder jammed up.
-With the firmware z speed not limited properly, i have lost steps due to rapid z moves.
-Filament strips and stops extruding.
-I have run out of filament.
-On a multi part bed, one part became loose and then slowly caused blobs to build up on other parts. It eventually knocked most of the other parts loose.
-Before I had my heated bed fully figured out I had a LOT of parts curl and then come loose from the bed midway through a print.
-I didn’t check the scale of one stl I downloaded from thingiverse and it ended up being about 4mmx4mm.

Got any more to add? post them below in the comments! I’m sure I’ll keep discovering more.

Hardware store fix for prusa belt tensioner

On my self sourced prusa I have been going back and forth on how best to tension the belts lately. I had a zip tie hack that actually worked out fairly well, but it had a fair bit of slop in it, and I think that helped set up some vibrations and Generally keep it from being the best it can be.
I love my local hardware store. I went there (twice) today and on the first walk there I remembered this piece of hardware that is generally used to tension screen doors to keep them square. I checked one out and I think it will be perfect for my y belt. I may even throw one on my x axis, but I’m not sure if I need it.
Here’s a pic

As you can see in the pic I have been experimenting with a very light y stage. It is perforated hardboard that they sell for hanging tools. The actual bed will go on top of there with 4, 5mm bolts and have the glass and hbp clipped to it.

I have also gone with a double wide skate bearing for the idler end of the x and y axis. If the two ends are aligned, then you don’t need anything else keeping the belt “on” the pulleys. Simple tension holds them there. This has made things much smoother and simpler compared to using fender washers.

Advice needed for Makerbot rebuild

To be honest: I posted this to the makerbot forums. I have had limited luck on those forums before so I am also posting here. I’d like to be able to get input from reprappers as well as makerbotters.

I’m rebuilding a late-model cupcake for fablab Boston. It has had some parts stolen, and I’m looking for advice on what route to go.

The two issues are that the motherboard has been stolen and it has a mk4 extruder. I know that the simplest thing to do would be to buy a new motherboard but the direct replacement (1.2) seems to be perennially out of stock.

Then we get to the fact that it still has a mk4 extruder. Since this will be used to teach kids how to print and do 3d design, I would really prefer if it had a bulletproof hot end. I think that generally means stepper-based, either mk6, mk7, or a wades style printed one.

Option 1_ I can get a motherboard v2.4, stepstruder mk7 complete kit, and an arduino mega 2560 from Makerbot for $85+$229+$65=$379

Option 2_ I can get a motherboard v2.4, another stepper driver, a stepper motor, arduino mega 2560 from Makerbot and some printed wades extruder parts for $85+$92+$65+free=$242

Option 3_ I can just get the motherboard v2.4 and an arduino from Makerbot and fight with the old dc extruder for $85+$65=$150

Option 4_ I can get a full reprap-style ramps board from reprapworld.com with stepper drivers, an arduino mega, a stepper motor and printed parts for a wade extruder for $130+$16+free=$146

Am I missing any better options? I’m leaning towards option 4 currently, but I could be persuaded. Am I correct in assuming that I can’t use repg on a RAMPS setup? That would basically be a full reprap toolchain conversion.

I’m honestly fairly excited about moving to a slic3r / pronterface toolchain because repG has always been fairly buggy and I feel like the cupcake is not that well supported in recent versions.

Direct drive Extruder gear

I’ve been on the lookout for the same kind of gear that makergear uses on their extruder for quite a while. Not the gearhead for the motor, but the actual part that bites into the filament.

I found cornwall model boats this morning, and I ordered a few from England. It appears to be a fitted end for a model boat u-joint, but it looks like it could easily work and they are available in both 5mm and 1/4″. I have a vague idea of using two of those on the shaft of this motor to make a dual filament bowden extruder.

The point of that would be to print the same part on the same machine twice at the same time. RAMPS has support for three thermistors and three outputs, so I could effectively double my print speed for parts that occupy less than half of the bed! An alternate idea is to use one RAMPS to control two machines, by either getting more powerful motor drivers or by getting twice as many. The only issue with that would be the 4 thermistor issue. Either printing PLA or some external circuitry could be fix that. I’ve been meaning to build up a bang-bang heated bed for some time now…

Boston Reprap User group meeting

I’m trying to put together a meeting of people interested in 3d printing. It’s called reprap because I think most of the people will come from there, but makerbotters and professional printers alike are more than welcome!

I’ve got a post over on the reprap forums trying to get an idea of how many people are interested and when we should do it. If you want to come out, then post a little bit about yourself over there and hopefully we can meet up!

makergear prusa z-axis fine adjustment screw detail

The makergear google doc only has a mention of this adjuster screw. I was really confused regarding what they were talking about. I finally saw it in one of renosis’s flickr pics and I decided I would take a closeup to show it in all of its glory.

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