3Dprinting on mendelmax3 (what a pain)

4 months in after my move to Kigali, I heard rumors of a 3d printer roaming around. After leaving my Afinia in NYC I was desperate to get my hands on my favorite tool again. Especially in a geography where tools are scarce and supremely expensive. Later I got word of a abandoned, dis-functional 3d printer gathering dust in someone’s basement. Through some quick research, It turns out that actually a colleague of mine had acquired it and was waiting to fix it. After a few days of nagging the beast appeared in our office. A “Mendel Max 3” a complete DIY system based on the RepRap rambo board. With a massive heated print bed it was everything a maker could want. Upon quickly starting to tinker I found out the X-axis end stop was broken. Fixing this was quite easy. You simple disable end stop homing for X-Axis in the Slicer. Was I was using CURA with RepieterHost so getting to the bottom of this one was simple and sweet.

After a few initial prints with PLA I quickly found out that the feeder stepper motor on the mendel max is prone to start skipping on the 1.75mm PLA filament. Specifically with softer filaments like PLA that’s been gathering dust for some time. Initial inspection found that the filament runs through a heatsink pipe section which sits between the stepper motor and the extruder heating element. (picture)

The 30mm fan located here was actually pulling rather than pushing air around the heatsink. In the process of removing this fan I unfortunatly shorted the connection leads and blew the 15A tiny fuse. These are impossible to find in rwanda. I was able to put in a quick acting car fuse to circumvent this problem.

Keep in mind that the documentation for the mendel max is decent but there doesn’t seem to be a whole lot of them out there so you’re generally relying more so on the RepRap ultimaker documentation.

While fixing the fuses, I’m unsure what happened but the firmware got corrupted so I had to reflash the EEPROM. The problem here is that I lost all my settings for my actuator steps and acceleration values. I quickly found that prints were coming out larger on the X Y axis and Shorter on the Z axis.

After fiddling around with the parameters I found that these values work the best. One thing to note here is that repieter host will allow you to change the EEPROM parameters through it’s own UI. However I found that modifying the values through repieter host didn’t persist. This might and will drive you crazy if you don’t know that it’s going on.

Download the latest image for your reprap rambo board and open “configuration.h” in your arduino IDE.

Scroll down and you should see a section like this. Below are my parameters.

// default settings

#define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,1600,99} // default steps per unit for Ultimaker/ 80 80 xy for mendelmax z 1600
#define DEFAULT_MAX_FEEDRATE {500, 500, 5, 30} // (mm/sec) // mendelxmax z-10.5
#define DEFAULT_MAX_ACCELERATION {1100,1100,10,10000} // X, Y, Z - 50 to 10 , E maximum start speed for accelerated moves. E default values are good for skeinforge 40+, for older versions raise them a lot.

#define DEFAULT_ACCELERATION 400 // X, Y, Z and E max acceleration in mm/s^2 for printing moves # changing from 1100 to 400
#define DEFAULT_RETRACT_ACCELERATION 1500 // X, Y, Z and E max acceleration in mm/s^2 for retracts

// Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
// The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
// For the other hotends it is their distance from the extruder 0 hotend.
// #define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
// #define EXTRUDER_OFFSET_Y {0.0, 5.00} // (in mm) for each extruder, offset of the hotend on the Y axis

// The speed change that does not require acceleration (i.e. the software might assume it can be done instantaneously)
#define DEFAULT_XYJERK 15.0 // (mm/sec)
#define DEFAULT_ZJERK 0.2 // (mm/sec)
#define DEFAULT_EJERK 5.0 // (mm/sec)

One other thing to keep in mind with the mendel max 3 is that starting to heat the bed and the extruder simultaneously led to overheating in the 2 pin connection on the rambo board. This resulted in a small melt down and could have led to much worse things.

Happy printing and drop my a line if you need anything printed in Kigali!

ABS Welding for 3dprinted objects

Recently, a close friend of mine sent me a video showing a method to fuse ABS printed parts together. Generally, with 3d printing, as the objects being created get further complicated , it’s a common requirement to print them as multiple part and  use some sort of adhesive to bring them together.

ABS Filament fusing is just like welding. Though, instead of using electricity to arch and thus cause heat, we are looking at using a dermal to cause heat through friction.

It’s a very straight forward process and works very well! I’ve included a video of me demonstrating after a recent test. The results are far better than using a hot glue gone or simply super glue.

A quick final  note: I’m using ABS filament for this. In principle I don’t see why PLA shouldn’t work though I haven’t tried it. If someone does I would love to hear their experience.

Poor Man’s DropCam

3d printers are both incredibly fast and obscenely slow. They are fast in the sense that what would in the past take you days to create using traditional tooling now takes you only a few hours and the end result is in millimetric precision. Though it’s also slow in the sense that the average print still takes at least an hour or more. As this technology is still in it’s early stages each print takes a good amount of baby sitting. I’m sure anyone who’s had a printer and left it unattended has come back to see this multiple times. fail From nozzle clogging or simply print board adherence are some of the common causes for such print failures. So what does dropcam have to do with this. Well I don’t have a fancy new makerbot so I can’t just launch an app and see how my print is doing. Also I didn’t want to drop a couple hundred dollars on a dropcam just to see my prints were progressing or failing. I found this incredibly useful piece of software called YAWcam(Yet Another Webcam Software http://www.yawcam.com/). The app I written in Java and is far from beautiful but what it lacks in beauty in makes up for by far in simplicity. You can simply launch your app and create a streaming webserver on the fly like this. I use it with my Microsoft webcam which is aging by the day.


Pretty cool though make sure you open your ports on your router so you can access it externally.. No more worrying and thinking “did my print fail”. Now I need to figure out a way to stop my printer if I see something wrong and feed the cats. Alp

Hot boxing your 3d printer (How to prevent warping when 3d printing with ABS)

If you’ve followed my pasts post you’ll probably already know that I really like printing in ABS. The prints come out sharp, crisp and the details in the resulting model are incredible. The good news ends however when you switch to larger models, even with a fully heated print bed the dreaded warping is difficult to prevent. When printing precision components the warping can cause problems including but not limited to making components not fit or even fail the print entirely.

I have a now aging Afinia-H series printer. With a 5 X 5 heated print bed it’s a awesome little work horse. Though as I get more serious with my prints I found that the warping becomes a huge issue for the reasons explained above. I almost can hear you say ” well, why not use PLA” , the answer is a bit complicated. Yes, PLA doesn’t warp but the prints are nowhere in quality with ABS. Any model with protruding or difficult shapes you can generally end up with the gooey PLA streaks everywhere.

After running around online reading what’s the best way to prevent warping without the use of support structures. The easiest way seemed to be to simply hot box your printer.

What you’ll need:
1. 13 X 13 acrylic panel (roof)
4. 13 X 15 inch acrylic panel
6. 1 inch hinges
1 simple latch

I was able to obtain large clear 3m acrylic panels from Canal plastics where they were cut in the sizes I needed. Hinges and latch I got from Home Depot.


And some hinges from home depot. After 30 minutes of some heavy drilling, You could skip the drilling and imply use duct tape as well thought I wanted something that I could fold and put away at times.

The end product turned out to look like this



The prints as a result have dramatically improved. You can definitely feel the heat building up when you preheat your bed and this is still certainly a requirement. I added some painters tape to the upper corners to prevent heat from escaping through the cracks. The result is large ABS prints with almost

Happy prototyping.

Solidworks and Surface Pro 3

When I first picked up my Surface Pro 3 on Monday I was extremely excited about the possibilities of having a full power laptop with the thin form factor of a tablet. I was really curious to see if it could be the ultimate creating machine, something I could do my dev work on as well as something that’s ultra portable. I also really like the idea of touch and having a pen for using with CAD software. I usually use my desktop for this work as it has a pretty beefy GPU that comes in handy, but when I compared the specs there really isn’t that much more that’s pushing my desktop ahead. So my first test was to see if I could actually work on the road with solidworks on my surface pro3.

To give a brief here are the specs of my desktop compared to SP3

Specs for desktop:
Cpu: Intel core i5 750@ 2.67ghz
Ram: 12 GB
GPU: Nvidia GeForece GTX 650 Ti
Disk: Samsung 840 Evo SSD

Specs for Surface Pro 3
Cpu: Intel core i5 4300@ 2.5ghz
Ram: 8GB
GPU: Intel HD 4400
Disk: unknown 256 SSD

When I run solidworks benchmarks;

Solidworks benchmark on SP3

Solidworks benchmark on SP3

Solidworks benchmark on Desktop

Solidworks benchmark on Desktop

So it looks like my surface pro isn’t as fast as my age old desktop PC yet, but the thought of Solidworks getting a touch makeover and the ability that it enables with portability is well worth the performance difference. The biggest caveat is obviously having the discrete graphics processor on my desktop where the differences is the most obvious but not terrible at all. For the novice Solidworks user this is well worth the difference as most designs I work with are quite basic. Currently solidworks supports certain touch features that are really cool like zooming, panning and rotating with touch. The pen also provides a precise means on clicking on toolsets. So far I’m quite pleased!


Adding a cup holder to the NYC Citi bike

I think the most amazing thing 3d printing brings to the table is to produce millimetric quality prints that can be used for modifying things of almost any shape.
You suddenly realize that the caliper becomes an immensely powerful tool, letting you make incredibly tight fitting builds that you can use to modify or advance almost anything. Last winter a friend of mine had a really cool idea. What if there was a cup holder on the citi bikes. Since a lot of people are using the bikes to commute. It would be pretty fun to have someplace to hold your beverage. I don’t support drinking and biking but having someplace to hold your coffee while you peddle to work just felt liked a good idea.

This is a proof of concept design that I put together using Solidworks 2014.

I wanted to create something that was simple enough and durable enough to hold a Venti Starbucks cup.

I also wanted to make sure that it was easy to attach the cupholder without using any extra components. For this I though of using the bungee cord that comes pre equipped with every city bike.

I went through a couple iterations trying to simplify the design to make it be stable and simple. I started working in Tinkercad but found it too limiting very quickly.
Moving over to solidworks had its learning curve but the benefits were immense.

I’ve uploaded the finished product to Thingiverse where anyone can download it and print it:http://www.thingiverse.com/thing:317540

PM me if anyone would like the Solidworks assemblies.

WP_20140625_14_35_48_Pro WP_20140625_14_35_26_Pro WP_20140625_14_35_37_Pro

Happy biking,