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

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 :cool:


Here are some photos of the the real machine.

http://www.tenfourmagazine.com/OldTi.../MayOTTpic.jpg

https://dmt55mxnkgbz2.cloudfront.net...28716-lin2.jpg

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

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

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.

https://i.imgur.com/XkvTu8oh.jpg


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

https://i.imgur.com/N6uuni6h.jpg

https://i.imgur.com/G8C9wsEh.jpg

https://i.imgur.com/0rIT7yxh.jpg

https://i.imgur.com/0SHEuPkh.jpg

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

More in the works.



Shawn

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

The bed looks good

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

Looking GREAT! Keep us posted!

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

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.

https://i.imgur.com/Gmy4TiE.jpg

https://i.imgur.com/XYMv5y1h.jpg

https://i.imgur.com/Lu54hZbh.jpg

https://i.imgur.com/hETEyKLh.jpg


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

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

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 :cool: 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 :D


https://i.imgur.com/CusBzuEh.jpg

https://i.imgur.com/VBZEncch.jpg

https://i.imgur.com/fGsn0x7h.jpg

https://i.imgur.com/l0D447wh.jpg

https://i.imgur.com/N4a8wmgh.jpg

https://i.imgur.com/6c24NZPh.jpg



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 :D




Shawn

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

Looking great

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

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

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

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

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

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

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

Those parts look awesome.

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

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.

https://i.imgur.com/ZGSQcGNh.jpg

https://i.imgur.com/jt68VLgh.jpg

https://i.imgur.com/SzuppMph.jpg

https://i.imgur.com/HB9Oy4Yh.jpg

https://i.imgur.com/IqQyGHmh.jpg

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-

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

Looking better Shawn

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

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.

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

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.

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 :thinking:

https://i.imgur.com/OiXJ5vth.jpg



-Shawn-

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

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.

https://i.imgur.com/SqqUCplh.jpg

https://i.imgur.com/Frtj4JEh.jpg


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.

http://www.coachbuilt.com/bui/l/linn..._catalog_2.jpg


https://i.imgur.com/hROBDx5h.jpg



-Shawn-

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

That looks amazing!

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

Very impressive!

Kerst

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

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!

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

Thank you!



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.

http://www.coachbuilt.com/bui/l/linn...port_specs.jpg

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

Wow - lots of information on that link, thanks! Towards the bottom there was a link for 'More Pictures', on that second page there are a lot of plan views and detail drawings.

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

Those are looking great, that's going to be a really impressive truck

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

Wow, good catch I can not believe I missed that :p

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

I'm back with a update on the Linn. I finally have some progress to show after a lot of research, I have a designed a prototype of the differential and final drives for the tractor. The trouble this entire build has been a lack of info, I quickly discovered that it is vary hard to find any technical or dimensional info about Linn tractors. I had a breakthrough when I found this post on the justoldtrucks forums by user 'Linntractornut' http://forums.justoldtrucks.com/2169...-Technical-etc in this post I found this image.

https://i.imgur.com/ycKgYNGh.jpg

Its a scan of a Linn parts book! And of the differential and final drives :drool: big thanks to 'Linntractornut' of shaing this info. So I finally had something to scale off.

Here is a photo of the differential in the real thing.

https://i.imgur.com/NxdBqQah.jpg

I this designed a model in CAD to allow me 3d print a prototype and hopefully CNC finished parts out of aluminum.

https://i.imgur.com/T4JevhGh.png


Lots of failed prints and designs later...

https://i.imgur.com/bSow66th.jpg

https://i.imgur.com/mxoLx89h.jpg



I have this.

https://i.imgur.com/hpbWh6Rh.jpg

https://i.imgur.com/MTJ9XuCh.jpg

https://i.imgur.com/UckdnWqh.jpg

https://i.imgur.com/Zr3TN2Eh.jpg


The differential is out of a 1/16 Traxxas E-revo and it is perfect size for this! I got the idea to use this differential from kerst's Liebherr LTM 1055 S-4 build. Thanks Kerst.

Now for the final drives gears I was going to cut my own as I now have a mill and indexing head but, I found that 48 Pitch gears which are commonly used in RC cars are perfect size. Using CAD I determined that a 12T pinion and 60t spur fits perfectly in the final drive case.

https://i.imgur.com/m4LHrhhh.jpg

So this how it sits. I will be working on machining the half shafts and a drive shaft, finishing the other track and hooking up a motor so it can finally move under its own power! :bounce:

https://i.imgur.com/Ce2bhHjh.jpg



-Shawn-

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

Glad to see this project alive and well....looking forward to seeing this one....

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

Really excellent design work! I love it. I usually end up with a pile of parts like that after a build also. Can't wait to see more.

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

That's looking good! I'm looking at those phillips head screws, though. There's a site called microfasteners.com that sells small hex head nuts and bolts that would look real good on that case.

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

I agree with you, the phillips heads do not look that good, but are good for quick and cheap fastening of prototype parts.

I'm going replace most of the 3d printed parts for cast aluminum or CNC'd parts as part designs are finalized. At that point I will replace all the fasteners with hex head nuts and bolts. I hope to post more about the aluminum casting as I get tools and work flow setup.


Thanks for the tip about microfasteners.com it looks like that is I will be purchasing my fasteners at.


-Shawn-

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

Well that is a coincedence. On the Dutch forum someone is also building a Linn logging truck.

I believe it is an older model, but the fact that it is a Linn truck is rare enough.

For the text you need Translate, but you can check the pictures: https://www.modelbouwforum.nl/thread...-truck.278238/

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

I'm still trying to wrap (pun intended) my head around the suspension. You're doing amazing work! I'm half-way (again, pun intended) doing a WWII half-track, and they pose a unique set of challenges.

I cheated and used a set of tracks from a robot kit (they're so cheap on Amazon/Fleabay it wasn't worth printing, and they're scaled pretty close), but otherwise not dissimilar to what you're doing. I think the track length is greater on those than on yours, so the suspension with its volute springs pushing on the bogies is simpler. Or at least better documented, lots of books about military stuff vs not so much for civvy.

The other pain I faced was that the front axle is driven, but the effective tire diameter of the track is much greater than the front tires (like 2.5x), so I couldn't use the same motor to drive the front axle as the tracks.

Oh, and it looks like you 3D printed the front leaf springs. Did you do them as one pack? I've done that for a coupla builds, with sufficient CAD work they *look* right, but I keep meaning to try printing individual leaves out of nylon and see if they are stronger / more accurate looking.

Anyway, wow, that's beautiful detail work, especially for parts that won't always be seen. I'll also be following with interest.

-- A

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

Shawn:

Any progress on the Linn?

Don

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

Not much I'm afraid. Unfortunately I have been on a hiatus from my projects due to having to move, All my tools are in storage (No room for them) I still have been doing CAD work and research for the Linn, my Gradall project and future projects :p (Hopto H-1900, Hopto H-700, Clark Michigan 175A, a tracked Gradall G-1000, Bucyrus-Erie 88-B) I have original manuals for them. I just need the time and space. Oh well maybe some day :thinking:

I'm still here, just in the background. Thank you for your interest I hope I can show some progress soon.

-Shawn-

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

Understand about losing workshop space hope we get to see more of this one though....oh and this one Clark Michigan 175A... and this one..Bucyrus-Erie 88-B... LOL

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

The 88-B would be quite a under taking for sure, the Michigan 175A should be pretty straight forward as it's quite simple in design.


-Shawn-

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

Lol... simple for you maybe....

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

Here is a small update on this project. It has been on the shelf for a while.

Some time back I was able to find a original parts book from a Linn tractor :drool:

https://i.imgur.com/Xxg53P4h.jpg

https://i.imgur.com/BwA8uxph.jpg

https://i.imgur.com/Pv1wn85h.jpg

https://i.imgur.com/8sIdZsoh.jpg







This inspired me to make a few parts for the drive line. From the parts book I learned that Linn used a splined universal joint, actually its more like a CV joint..

https://i.imgur.com/e3uJokKh.jpg

https://i.imgur.com/j3iBouAh.jpg

https://i.imgur.com/zgNHGHbh.jpg


Here you can see the scale of the parts.

https://i.imgur.com/m7vaUDDh.jpg


Rear hub and brake drum.

https://i.imgur.com/pA4pAJOh.jpg

https://i.imgur.com/wXnioOqh.jpg

https://i.imgur.com/EQT5MZ6h.jpg


I also machined a input housing for the differential to replace the 3d printed one.

https://i.imgur.com/MnezmuUh.jpeg


G-code test.

https://i.imgur.com/3EKE0obh.jpeg


Finished part.

https://i.imgur.com/OAtdd2Zh.jpg

https://i.imgur.com/hm95pNah.jpg

https://i.imgur.com/DBDwinOh.jpg

https://i.imgur.com/w5pFR6ph.jpg




-Shawn-

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

https://i.imgur.com/28hSCwBh.jpg

https://i.imgur.com/YCEJ4UUh.jpg

https://i.imgur.com/gp2kO0th.jpg

https://i.imgur.com/I2V9y2th.jpg

https://i.imgur.com/YXarT6hh.jpg

https://i.imgur.com/JVEJTruh.jpg




-Shawn-

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

Awesome to see this getting worked on again. The drivecup and pinion mount are beautiful. Do you plan on swapping all the printed parts for metal, or only high stress parts?

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

I too am very glad to see this again. Some really great work you've done. Love the old manuals. I always look for them when I'm planning a build, they are a great reference to have. Often the only way to get dimensions if you don't actually have access to the real thing. What size milling bit did you have to use to cut out that input housing?

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

Thank you.

I plan to replace all the 3d printed parts starting with the drive train. Planning the differential housing tool paths and work holding is proving to be difficult, but I will get there.

I used a 2 flute 1/8" (0.125) ball end mill 3 roughing passes 1 finishing pass.



-Shawn-