The Australian distributor of the RapMan 3D printers were kind enough to lend us a RapMan Version 3.1 kit to build, review, run some test prints and just get our opinion on the machine. After having recently built a Makerbot Cupcake CNC we still had our tools at the ready and we’re keen to jump into another build. The RapMan Version 3.1 is an entry level 3D printer and retails for just over $2,500 AUD.
The RapMan design is based around a Z axis build platform with a moving extruder head (X/Y axis) which is the opposite of the Makerbot Cupcake design which moves the build platform and has a Z axis extruder. In our opinion, the RapMan design is superior to the cupcake CNC as it allows for a much bigger build platform (around 4 times the area of the cupcake) while only being around twice the size. Interestingly most commercial 3D printers follow this same design philosophy as it allows maximum print size with minimum footprint.
Unboxing the RapMan
We love getting gadgets in the mail and opening a big brown box is always going to be good fun, especially if it has a 3D printer inside. One thing these guys have down pat is the packaging. This thing is seriously well packaged and there is a hell of a lot of stuff in a very compact box. Everything is clearly marked and easy to find, they have even gone to the extent of laser cutting some MDF boards to securely hold the stepper motors and steel rods. One of my favourite touches is the bolt tray which has each size and type of bolt in a separate bin which are all numbered and referred to in the build instructions. This makes looking for the right bolt a breeze and your much less likely to have any bolts go missing. It solved a lot of arguments over who was using the correct fasteners!
Building the RapMan is not something you can knock over in an afternoon! We managed to throw together a Makerbot in roughly 4-5 hours (that’s with 2 people working on it) and we were hoping we could do the same with the RapMan, however we we’re informed that it would take the good part of a weekend to complete. However being a fairly ambitious bunch of dudes we set ourselves a goal to knock it over in one day! The first stage of the build is the slowest (well at least it feels that way) and involves assembling all the laser cut acrylic corner clamp plates. These guys are a little fiddley but once you knock these over the frame comes together very quickly. The scaffold style of the RapMan means that the whole frame feels a little loose, but once you have tightened up all the corner clamps and have the diagonal braces the frame becomes very very solid. Every part is numbered and is easy to locate, except for the laser cuts parts which you need to refer back to a visual guide in the instructions which is great as long as you can resist the urge to strip out all the parts and remove the protective films before waiting until the parts are required.
Speaking of instructions, this is another area where BFB have excelled. Not only do they provide detailed step by step PDF’s instructions but they also provide embedded video’s and these really neat animated 3D assembly video’s which show how each sub assembly goes together. We found ourselves bouncing back and forth between the 2D and the 3D guides to make sure we were putting things together in the right orientation.
The motion system for the X and Y axis use captive linear ball bearings running on 12mm solid stainless steel rods. The Y axis is especially impressive on this machine as the Y axis is driven on both side which provides very smooth motion with no crab walking. This extremely smooth motion system is one of the main reasons why these machines print such good parts. The Z axis relies on standard “all thread” rod with a neat spring loaded dual nut setup to take any slack. We think that the machine could really benefit from a decent set of professional ball screws and rods to tidy up the Z axis but we know these things aren’t cheap so we’re glad that the X/Y Axis got such a good setup.
The extruder and hot end
After having heaps of dramas getting a Makerbot Plastruder Mk4 to feed plastic consistently with out stripping the filament and not having much luck we we’re super impressed with the design of the RapMan extruder. The plastic drive mechanism of the RapMan relies on a threaded shaft to feed the filament in a worm drive type arrangement. This set up has two major advantages over the toothed gear design you see on Makerbot’s and Mendels.
- You get a huge contact area with the filament, approximately 15mm!!! So its less likely to strip the filament.
- As the threaded shaft acts like a worm gear so you don’t need any complicated gearboxes to get the right feed/motor ratio.
The extruder is driven using a stepper motor and a set of acrylic gears which I was a little worried about at first, however after seeing how little load is put on the gears due to the worm thread drive mechanism, I was quiet happy with them.
One area which causes people a lot of trouble when assembling 3D printer kits is the hot end. Soldering nichrome wire and tiny thermistors is not everyones cup of tea and can lead to all kinds of problems which you don’t realize you have, until you complete the assembly and plug it in. Disassembling the 3rd time gets a bit old! However, you won’t have any of those dramas’s with the RapMan as it comes shipped with a professionally assembled and tested hot end. Just bolt it on, and your away! Yes it really is that easy.
The moment of truth!
Once we had the extruded bolted and and the drive belts tensioned up it was time to see if all our hard work had paid off! Upon connecting all the wires into the PCB we nervously plugged the power adapter into the main’s and flicked the switch….. The LED’s blinked, the fans started spinning and the tiny little colour LCD screen shone into life. Success! Amazingly we must have followed the instructions correctly because everything seemed to be working! A quick look around for any escaped smoke… nope… we’re in business. We checked the movement of all the axis with the manual controls and they all moved in the right directions. Time to load in a program and give her a run. We decided to try the standard test raft first. Load the program onto the SD card, whack it into the RapMan, load it up and cross our fingers. The machine sprang into life and sent the head into the home position. All limit switches registered and looked to be in alignment (luckily). The head then traveled diagonally across to the build platform where it came to rest in the opposite corner as it headed the hot end. We obnoxiously watched the temp increase. Once the desired temp was reached (240ºC) the head moved off and started the first of 5 test rafts. To our surprise its laid down a pretty neat and consistent raft in all four corners and then one in the middle. It WORKS! A quick calibration of the build platform to make it level and we quickly scoured the net looking for our first test part. We didn’t want a boring cube or box so we looked around on the BFB website and found a heart shaped jewelery test file which we thought we be a good first test. We loaded it up and hit print and away it went. The raft looked great and before long we we’re intently watching the part build up layer by layer before our eyes… Amazingly the part come out spot on! After playing around with a Makerbot for a few weeks now we we’re expecting to have to tweak a few settings and make a bunch of adjustments to get it to run successfully but straight out of the box the RapMan was printing great parts!
BFB supply a supper easy to use software package for transforming your 3D models into g-code that the RapMan machine can understand. The program called BFB Axon V1.11 is downloadable from the BFB website along with a very informative manual (not that we have read it).
The software allows you to open an stl file (3D model), move the file into the orientation that you want to print it in and then position the model on the build platform. Once the modle is aligned correctly the model is ready to be processed, just push the build button and the software will slice the model and produce the g-code file along with all the necessary feeds, extruder speeds and temperature settings. Once the file has been produced (this may take a few minutes while your CPU crunches the numbers) push the save to SD card button, place the SD card (supplied with machine) into the RapMan’s CNC controller and print. It that easy!
Because BFB Axon V1.1 is made to be used with the BFB products once you select the machine “RapMan V3.1″ and the material type “2.5mm ABS” all the setting are automatically configured for the best build quality. This is not to say that you don’t have any control as all setting can be overridden in a very easy to use settings menu. Another impressive feature of the software is the ability to view g-code files in a visual 3D format. By sliding a scale on the right of the viewer your are able to view every layer of the g-code if needed.
All in all the software is very good but unfortunately if you have a MAC your out of luck as the software is Windows based. This really isn’t a big deal though, because there are a few other free open source software packages available for download such as SkeinForge that will generate code for the RapMan just fine.
All up the RapMan took us a good 12 hours to assemble with 2 people working on it but once it was complete it was up and running and printing decent parts with out any adjustment with factory settings. That in itself says a lot. One of the things that really struck us when using the RapMan was how quiet the machine is when its printing. The linear bearings and steel rails allow the X and Y axis to move freely without making much noise at all. If you have ever been standing next to a Makerbot when its printing you will know that they are not exactly quiet (the timber box resonates the sound of the stepper motors very well!). The RapMan on the other hand makes no more noise than a modern laser printer and is definitely office friendly.
The build process is a little more complicated than a Makerbot mainly due to the scaffold frame design however its not any harder, it just takes more time to assemble. When you consider the size of the build platform of this thing and the ease of operation its pretty hard to look past it as one of the best value for money 3D printers on the market. The Makerbot cupcake CNC is around half the price of the RapMan but your only getting a 1/4 of the build size so if you want to print parts bigger than 100 x 100mm its worth having a good look at a RapMan.
We were very impressed with the RapMan and would highly recommend it to any one who is considering getting a Rep Rap style 3D printing machine. Two thumbs up!
If your interested in purchasing a RapMan visit www.rapid3D.com.au – The Afforable 3D Printers