Hello everyone. Some may recall a few weeks back that I was conducting research on the rare Caterpillar Twenty Logging Special with the Willamette Ersted dual drum winch. I was able to get my hands on enough information to begin my model weathering project and thought I'd share it with you all. I had seen high resolution photos of several Cats sitting at the Camp 18 site and wanted to duplicate their condition on a Cat Twenty in model form. My base for the project is a Norscot ACMOC Twenty. While it would not have pulled it in real life, I'm also combining a 1:16th scale early Hyster logging arch with Trackson tracks into the equation as an accent. More on that piece later.

Moderators, if this is in the wrong spot please give me the boot and I'll post it somewhere else. If it is, I'm sorry...

The Prototype: (With special credit to Roger Amato @ Classic Dozers)


The model: (Image credit to Cranes Etc.)


I'll be posting updates to the project as I move forward. I first have to complete the 3D design of the components of the Willamette Ersted winch to go on the back of the Twenty for 3D printing before I begin weathering. Yep, lots of one-off material about to be 3D printed! I've aleady spent a good portion of my free time over the last three days to design the housing part to the winch. This will be the left housing. Looks pretty accurate:


More soon!
Calvin Bensch II

What modeling program (SolidWorks, Alibre, etc.) and 3D printer are you using?

I use Google Sketchup Pro for the 3D modeling. The 3D slicing profile generator and printer controller is via Repetier-Host. Both superb products that I've had excellent results with. The Printer is a Felix 2.0 from Felix Robotics in the Netherlands. It's been a stable platform that provides massive prints in comparison to the competition. I print PLA (Polylactide Acid) as opposed to ABS as I've found the famous ABS warping issue to be genuine.

If anyone wishes to see the hi-res photo of the Twenty from Classic Dozers that link is here:
classicdozers.files.wordpress.com/2013/0...ing-special-1929.jpg

I'm always interested in what combo's people are using. 18yr SolidWorks veteran myself, I've been eyeing the MakerBot for a while. Thanks for the info.

The real breakthrough will be when we can print full strength metal parts.

I admire you for being proficient in Solidworks. That's a sophisticated and professional platform! Very cool!

I believe that no other manufacturer has as much experience or sales volume as Makerbot. Historically, they also might be the oldest manufacturer of consumer grade printers. I can't say for certain. The enclosed print environment is a super feature. The Makerbot Replicator 2X was on my list of possible printers to acquire though I recall it being designed for ABS only. I prefer PLA, though many people would disagree with me, which is fine. However, I'm quite fond of my Felix printer!

On that note the winch housing printed beautifully tonight! I have eight slicing profiles that depict different resolutions and I used a .1 mm print layer for the highest definition. I'm now in the home stretch of designing the PTO to fasten to the rear of the Twenty. I have a feeling both pieces will be printed several times over with multiple tweaks. It's just the nature of the beast. Then there are the drums, braces, levers, seat and seat post...and, since I'm making this a completely mechanical accessory I'll be playing with some involute gears. Pictures tomorrow!

very interesting these 3d printers ! and any pictures of it in proces and end result are very welcome here!!

"MARCOTEN" wrote:

very interesting these 3d printers ! and any pictures of it in proces and end result are very welcome here!!

Thank you for that. I'll upload video of the printer making my next component to YouTube and post it here.

From a computer model profile to an actual tangible component. I am not yet sure if it will fit to the drums, internal gears and PTO housing yet...but that's why they call them "prototypes." I had experimented with raised text on prints before and have found that anything with a solid surface less than .5mm does not print clearly. Therefore I couldn't add the "ERSTED M.M. CO" at the top or the "PORTLAND ORE." at the bottom due to size restraints. Which is annoying because I'm OCD about that stuff.

I made the ERSTED text raised .4mm just to have a slight accent without being in your face. I also wanted to note that the actual winch said "Hyster" across the center. But as "Hyster" is a current brand I didn't want to upset anyone at the company. Ersted existed so long ago and is such an old manufacturer I figured no one would bat an eyelash.

The 3D Model again:


The print:

thats amazing! i heard they will also"ship" a 3d printer to the international space center in the next supplys to them.