Other Stuff

I accidentally ordered a roll of ABS filament (I had been using PLA) so that forced me to do a bit of tweaking on my 3d printer. Tried the glass bed with it, didn’t work very well. Ended up going back to the regular one but I don’t use painters tape anymore, just print right on the bed. Everything sticks fine although I’m not sure I like ABS for people. Anyhow, I have been meaning to post files of my people if anyone wants to play with them or 3d print. I use Makehuman to create them, Blender to pose em, Netfabb to seal the ‘holes’ and Cura to slice them for my Creality Ender 3. Almost all of these files are originals but I may have a few things I downloaded from thingiverse.com or something like that in there, they are just dumps of my 3d folders.

There are two zips, one has the blender files which are the ‘source’ files. You can load these into Blender and pose and sculpt them in various ways, then export them into stl or obj files for printing, that file is here:


The other one has already processed files, exported from blender ready to be loaded into a slicer for 3d printing. That zip is here:


Computer Lab

My current setup. Left to right. CHG computer, RaspberryPi development, ProxMox VE (repurposed PowerEdge), Windows 10 Fileserver, Ubuntu/Ansible box, printer, Windows 10 main machine, Solder/Lab area for model train controls, Ender3 3D printer.

Here is a guy I made in MakeHuman and edited in Blender. He came out quite well and I only had to do minimal changes in blender for the pose. Just adjusted his hands a bit so that they would be flat against his leg and sides. Of course, as usual, you have to edit the head mesh to remove the eye sockets and mouth but using the hide and then ‘select loop’ tool it’s actually pretty quick.

I have zipped up the final OBJ file (obj was a bit smaller than an STL) and uploaded it here: http://martinsant.net/new3d/

This mesh has been tweaked and run through netfabb to remove any holes or openings in the pants and sleeves, etc. I am not sure of the exact scale of the object but I just resize in Cura before I print it. For 1/29 GScale, he is 60mm tall which comes out to about 5 feet 11 inches or so.

Finally got all the parts happy together. Ended up with a combination of several components I had not tried before- a Pololu 18v7 motor controller plus a relay for the lights. I had to add some code to the PT receiver but I think I will keep that as a configurable option from now on. I tried to use an old soundraxx sierra board but it just didn’t work very well. So I also added an old soundtraxx tsunami which gives the ooh-gah sound but unfortunately only diesel locomotive prime mover sounds. The speaker is a tiny 2 inch visaton-frws-5-r-2-fullrange-speaker, but it sounds pretty good.

Doing a little running outside today, it was a nice day. My layout is a bit thin, needs some ballast and maintenance, it’s been a tough weather season this year, I have not kept up.

So here are the insides. I like that it’s all self contained, no track power- 3000mah LiPo prime mover, the 5A power amplifier with the big heatsink drives the TCSWow. (You can’t see it here, its underneath the Xbee Receiver)

My receiver board has a standard Xbee sort of foot print for the network chip, it’s what I originally designed it for. Lately I have had a Bluetooth compatible radio chip in it so I could drive my trains with my Android Phone. I swapped that out with an Xbee Series 1 so it would get the Protothrottle network traffic. I coded up some new firmware for the receiver and flashed it into my USAT PRR GP9. Worked really well. I think I have most of the bugs worked out, just needs a bit of tweaking.

I changed the brake on the protothrottle to ‘pulsed’ on F7 for the TCSWow and it works great. I love that brake squeal. I still have lots to do here, the decoder is still ‘out of the box’ I have not tweaked it much at all. I want to configure it with my smart phone, I don’t like the ‘audio assist’ thing much- I have some of that code built out but it will take a while to get it going.


Latest incarnation of the Phone Throttle Contraption. The phone communicates with the Xbee Controller via bluetooth, a custom app runs on the phone. This is based on previous experiments with an android tablet, you can read about that here- Android, Bluetooth and Xbee

I’m trying to emulate a generic sort of DCC throttle ‘feel’ with this. I have all of the base code written and tested, it’s just a matter of pulling all the parts together. Slowly I’m getting everything working.


I picked up a cheap Aristocraft U25B in Chessie paint the other day and have been taking it apart so I can rebuild it. The idea is to get from the toy like unit I have into at least a semi-scaled sort of model. The photo above is the closest prototype image I’ve found to what is depicted with this Aristocraft rendition. So I’m stripping it down to the base parts with the idea to install my control system, batteries and sound. And of course, a bit of paint and detail work- it is a bit cheezy with the cast color parts. Yuck. So anyhow, I’m getting there. Below is an image of the original model. More in a later post.


PCB as Art?


I’ve been doing quite a bit of PCB design these days, here is a version of my controller board, the ‘microwidget’. It’s quite compact. I have not had any made yet but I thought it came out really sort of, well, neat. Like art kinda.

All total I have about five or six small circuits for doing control networks- specifically for large scale model trains. DCC input and output, servo control, DC brushed motor control, reversing relays- all via Industrial strength Xbee Network wireless.

I’m also thinking of making an apt-get debian package to install JMRI on a RPi 2 and gitlab for my code. Hmm.

I think I need a Kickstarter 🙂



Here are the final two prototypes. The master obviously connects to the Prodigy Express and sports a long range antenna for max transmission power. What I’m thinking here is this is the module that will be connected to my RPi 2 which I am planning on running JMRI on. The Pi 2 will also have a long range wifi antenna on it so I can use it to source web pages to my phone and tablet. My standard handheld design is what I actually use to drive my trains with.

The second pic is the client. This one is fairly comprehensive and has quite a few parts but I use it as my standard prototype rig. In addition to the control board, it also has an (expensive) Pololu 18v7 motor controller and a current sensor. The DCC output stage is the board with the large chip beside the speaker. All it is used for in this incarnation is to drive the Econami Diesel DCC decoder which powers the speaker on the right.

Here are all the parts labeled, you can click on the picture for a larger version-