LINN Model DD-15 "HafTrak" Dump (1/14)

[Krewmember]

I have been doing research and planing for this build over the last couple days. I got dimensions of the machine so I already have the design for the frame and some of the dump bed done. So it's time to get this thread started


Here are some photos of the the real machine.





This is a short video I found of the machine in the first photo.
https://www.youtube.com/watch?v=hiYnQv6Y1vg


My plan is to fabricate it mostly out of steel and aluminum. To limits of my current tools at least. I will post updates as I make progress.


Shawn

[Krewmember]

It was a pretty nice day today, so I got out to the garage and to started on the dump bed. First I printed out the design for the bed to scale and used spray adhesive to stick it to a side from a old washing machine I had in my scrap pile, next I used a jigsaw to cut it out.




I got some wood blocks and a hammer and started bending it to shape.. after a couple hours I got this it's a little rough but the bent steel makes it look like a tonka









I still need to weld it and work on a lot of small details. But it's a start.

More in the works.



Shawn

[skeeter]

The bed looks good

[Krewmember]

Originally Posted by skeeter

The bed looks good

Thank you. Hopefully I can get all the small details for it worked out.


Anyway. I just finished the front axle. It didn't come out too bad considering I used hand files it has no holes for mounting or spindles yet I want to make the spindles first so I can get a good fit.










I'm just making random parts as I design them. The spindles should be next I just need to buy a few more things for the lathe to get it up and running.




Shawn

[Krewmember]

No updates for quite a while. But I finally have some more progress to show, just some more random parts. I got my lathe running and turned some wheel blanks for the front.

Also a 3d printer has been added to my tool collection and I love it, the amount of detail that is achievable is amazing. I was able to model the radiator with the cast "LINN" logos on the support frame and the upper radiator also bolts, the radiator cap, and even the holes for the wire bale that hold the cap down
















I'm going to model and print the engine next I'm planing to put a small motor in it so the radiator fan spins




Shawn

[FabOne]

Looking GREAT! Keep us posted!

[Mikem]

Looking great

[Hemi1966]

Nice work Shawn.
Can I ask what 3d printer are you using ?

[Krewmember]

Thank you.

The 3d printer I'm using is a JGAurora A5S I got from a overstock auction for a really good price. The radiator was printed using Cura as the slicer with 1.75mm PLA, 0.1mm layer height, 40mm/s travel speed and 20% Infill. I think the printer is over extruding a little, I may reprint it before final assembly with tuned extruder rates but I'm happy with it for now.



Shawn

[Krewmember]

Also I will be releasing all the STL files I make for this project. so if anyone else wants to make a LINN crawler it will be easier for them



Shawn

[frizzen]

Those parts look awesome.

[Krewmember]

Here is some more random parts that have been designed and 3d printed.

The parts are the corner brackets for the rear frame, front crossmember with starting crank support, idler wheels and some track links for testing. The tracks seem to work well, I used old bike spokes as pins which are self retaining.











At this point I need to get the frame designed and assembled so I can design the drivetrain, just need to get some 1/2" aluminum square tubing that I will cut in half for frame rails.



-Shawn-

[Mikem]

Looking better Shawn

[skeeter]

3D printed tracks are no joke! I know a guy that 3D printed tracks for his Faroe tracked loader. The 3D printed tracks had more hours on them than the stock metal track pads. He finally found an aftermarket track set, & is slowly replacing the stock pads as they break.

The radiator looks very good! I'm anxiously following this thread.

[Krewmember]

Originally Posted by Mikem

Looking better Shawn

Thanks. I still have a lot to learn about 3d printing and have many more tweaks to do but, the nice thing about 3d printing is you can reprint the part as many times as you need to get it right.

Originally Posted by skeeter

3D printed tracks are no joke! I know a guy that 3D printed tracks for his Faroe tracked loader. The 3D printed tracks had more hours on them than the stock metal track pads. He finally found an aftermarket track set, & is slowly replacing the stock pads as they break.

The radiator looks very good! I'm anxiously following this thread.

That's what I like about 3d printed parts if drivetrain components wear out you can just print new parts. I love metal models but this 3d printer is allowing me to model at much greater detail and scale then my current metal working tool would allow me. The 3d model for the radiator took me 2 weeks to model. But it's the centerpiece of the front of the model so I wanted to get as scale and detailed as possible.


Anyway, while I'm waiting for the aluminum for the frame to arrive I have started modeling the cab. It's made of mostly styrene but the roof is 3d printed out of PLA. It kind of looks like the cab on a Peterbilt 334





-Shawn-

[Krewmember]

Quick update. The frame is starting to come together, I still need to design and print the brackets for the cab support rails it also needs the dump bed rails.






The driving driving gear and tracks are coming together nicely as well. it will work just like the real machine with a sliding frame and springs to keep track tension, A rocker block, runner blocks and a chain of track rollers for that "Flexible Traction" system that made LINNs different from other half tracks.








-Shawn-

[skeeter]

That looks amazing!

[kerst]

Very impressive!

Kerst

[crueby]

Looking great! Did you find plans/drawings somewhere, or are you going from old pictures? Not sure if there are any of these still in existance? There are a few of the Lombard versions around. Will be following this build!

[Krewmember]

Originally Posted by skeeter

That looks amazing!

Originally Posted by kerst

Very impressive!

Kerst

Thank you!

Originally Posted by crueby

Looking great! Did you find plans/drawings somewhere, or are you going from old pictures? Not sure if there are any of these still in existance? There are a few of the Lombard versions around. Will be following this build!

Thank you. I have not been able to find drawings from the manual, but I was able to find this export specs sheet from this page http://www.coachbuilt.com/bui/l/linn_mfg/linn_mfg2.htm it got me good reference dimensions and from there I'm scaling pictures and videos that I have found on the net and working off them to design the individual parts in CAD for 3d printing or fabrication.