Examples

Here's a few pictures of things we have printed.

A functional whistle from thingiverse.com

A dragon's head from thingiverse.com

A test part we designed to to push our printer to the limit. It was also printed on a ZPrint 650 and an Eden 250 for comparison's sake 

 This, and the next two pictures, shows our attempt to infuse a printed part with metal hinges. The part was constructed with a cavity that matched the hinge. When the printer had printed the cavity and was about to print the next full layer, we paused it and put in the hinges, so the top of the hinges was flush with the topmost layer on the part. The paper is necessary because the PLA doesn't stick on the cold metal. The whole thing turned out to work great.

Additional info

Because we had some trouble with the whole construction of the printer being a bit unstable, we made a removable build platform, so it has become a lot easier to remove the printed parts. Before, when some of the parts were a bit stuck, some of the power that went into releasing the parts made the printer bend and warp a bit. The new platform is simply a thin piece of acrylic, with holes at the edges so it fits between the screws on the original platform.

The display on our printer has been broken since we received the printer. Some times it works fine, and sometimes it's completely screwed like this:

We can still use the printer "in the blind" when it's like this, and when we restart the printer it usually looks fine again. We talked to BitsFromBytes support and they have kindly sent us a new screen, but we haven't had a chance to mount it yet.

New corners

We have had some trouble with xy-wobble, and a bit of investigation seemed to point to the acrylic corners as the perpetrators. It seemed that the ball bearings did not fit properly into the laser cut sockets. Because the bottom of the socket was not flat it made the bearings lie at an angle, which seemed to make the threaded rods move off-center.
After finding a new printable set of corners for our RapMan 3.1 on Thingiverse, we decided to try them out. They were designed by another RapMan user, chylld, and can be found here. The reviews seemed positive and chylld has made extensive tests with them to ensure stability.
After printing, and mounting them on the printer, everything seemed good, and the wobble was reduced a bit.
However, when we came back to the printer the next day, the first print was horrible. It turned out that the friction between the steel rods and the corners was too low and everything was moving around and falling apart. After a good half day or readjusting the printer and applying duct tape between the rods and corners, the printer was back on track.
We suspect the reason to be our material, PLA, because the corners are designed and tested in ABS, which may explain the difference in friction.
We also had to redesign the front left and front right corners, because the pull from the y-motor warped the corner part, and the z-motor plate will also have to be redesigned at some point as it's sagging a lot.
All in all our experiences with these new corners have not been good, but for now, we blame our PLA.
Oh, and the xy-wobble is still there.

Untitled from anders sund on Vimeo.

Sagging Platform

As other people with a RapMan printer we also experienced problems with a sacking build platform. Supposedly this should increase the wobble in the xy-plane. We checked out some examples of people replacing the platform with a piece of 16mm MDF. Instead of this we have tried to use aluminum T-profiles bonded to the acrylic using strong adhesive glue.
This actually helped on the sacking platform and also helped a bit with reducing the wobble. Unfortunately there turned out to be a second factor influencing the sacking: our threaded rods are slightly bent. This forces the platform to twist and compress. So after running the printer for about 20 hours of prints the aluminum T-profiles started coming lose. So now we are still experiencing som sag and an increased wobble.

Wobble arresters

We have really been having some problems with our not-straight threaded rods. So we decided to do something about it other than trying to straighten them.
We checked out some different possible alternatives. you can see them here, here and here.
We ended up designing our own wobble arester based on the fact that we have experienced a really low friction between PLA and Acrylic. We were also quite keen on not having to disassemble most of the printer. So this is what we ended up with:


The basic principle here is that we bypass the z-axis threaded rods and rely on theouter static precision rods. Hereby we only use the threaded rods to support the platform and move freely in the xy-plane.


The screws we had at our disposal were to long so we printed a quick-fix. They will be replaced at a later time.

Our experiences

The printer is finished now and we spend most of our time printing stuff. The process has not been without complications though, and we still have some trouble. But it's a long story so let's start from the beginning.


The building phase was quite simple and the instructions were generally good. A few places the manual had some mistakes that we had to work around, and here the 3D manual came to our rescue. Our first major problem was when I cut the nichrome wire in two pieces, when it should have been one! Apparently the kit can come with two different kinds of nichrome wire, an uninsulated and an insulated variety, and the manual contains different sections for each kind of wire, which I wasn't aware of. So I happily started out following the section for the uninsulated wire (we have the insulated one) which ended in two unusable pieces of wire. Luckily the good people at Labitat came to our rescue and supplied us with some nichrome wire. It was a bit thinner than the original, and the resistance was higher, so go get the same resistance as the original piece, we had to cut it to a third of the length. It ended up being 21cm and 4.2 ohm and it works perfectly.


Our second challenge was the hot end and especially the fire cement. The sample we got was very dry and nearly impossible to mold around the nichrome wire and thermistor. We added a tiny amount of water (one or two drops) which made it a bit easier, but the result is still not pretty, albeit functional.

Beside these challenges, the build went fine, but the extruder and hot end part took a lot more time than we expected.


When we started printing with our PLA from Orbitech, it suddenly got stuck. After some tinkering and disassembly of the extruder, we found the reason. We were trying to find the right temperature for our PLA and had left the heater on for too long without running the extruder. This means that heat crawled up the hot end and made the filament soft, so when we turned on the extruder, the filament was just compressed inside the extruder instead of being pushed out. So, the lesson to be learned is: Don't let the heater run at high temperatures without also running the extruder.


We have also printed replacement parts for all the corners, which introduced a whole new slew of problems, but more about that later.

Hello world

This is the first print. We choose a "cup of victory" aka a mini mug for our first part to print. It turned out really well. We tested it to see if it was watertight - and it was. This print is with the ABS fillament supplied by bits from bytes.

Our RapMan 3.1 printing a perfect, watertight mini mug. from Morten Georg Jensen on Vimeo.

last assembly

Here is some of the last parts of the assembly. The video shows the assembly of the hot end of the extruder.

better late than never

Okay. So here is some more of our progress. We are actually done with the assembly by now and have started printing. But we cannot upload anymore today because of an uploading limit. More will follow.

2nd assembly from Morten Georg Jensen on Vimeo.

3rd assembly from Morten Georg Jensen on Vimeo.

1st assembly

Yesterday we started assembling our printer. We worked for 10 hours and I would say we are approx. 75% done. It was a surprisingly easy build, although there were a few mistakes in the assembly manual that we had to figure out for ourselves. I can't wait to finish it and start printing.