1/25 6 Axle Lattice Crane

[Southgate ll]

Way-ell, guys... It's been a while! As life goes and comes up with all manner of distractions, not in a bad way necessarily, I've been MIA here. I had been trying for a while to log in but couldn't get my password(s) to work, so I changed my forum name a little and re registered. But I'm back

The Crane.
Long story as short as I think I can get it; as I was about 99% finished with this project, I faced up to the fact that I was never quite satisfied that I took some liberties in building it. It's supposed to be 1/25 scale, but in reality, it was pretty over sized for the class of crane I was shooting for. I was working with and around components and skills I had at the time.

Fast forward to 9-18-2017. That's the day I decided, after extensive measuring, calculating, sketching, and even a bit of guessing, I decided to bring it into the proportions I'd really be happy with.

The upper unit needed narrowing. That's involved enough. The carrier however was far and away the harder to downsize. It had to be narrowed, lowered, and the length shortened, each on it's own a big challenge.

This post so far took longer to write than I thought it would, but I'll post it lest I should lose it somehow. I'll be back with pictures and progress notes soon. It's good to be able to log on again! Dan.

[Southgate ll]

I just spent about 1 1/2 hours writing and posting pix to update progress. Hit "preview post", POOF! Gone.

[Originalrob]

Hi Dan
Welcome back to the forum ! I have only been about a short time (on my first build) so it’s good to have some veteran builders about for advice and different builds like your crane. Looking forward to seeing your progress !
Rob

[Southgate ll]

I need some help here. When I open page 6 of this thread, I am logged in. When I go to page 7, I am NOT logged in, and may not post replies. And, try as I might, I can not log in. I definitely know my password and forum name. I am replying from page 6 as I write. Ideas?

Edited in: now on p 7, since I replied from page 6, I'm logged in. Odd.

Anyway, thank you, Rob. I have to tell you I am anything but a veteran when it comes to RC. This crane is my only venture into RC, and I only RC'ed it cuz it was the only way to make it functional at any level. I'm mainly a 1/25 scale model truck builder. (and switch off occasionally to HO model RR, simple DC only) And when you look at the caliber of machinery being engineered and built on this forum, you'll see I'm kind of a runt here. That said, I'd be glad to help any way I can.

As mentioned above, The crane is undergoing a heavy makeover to downsize it Here's a before picture. Note the extended front end, the size of the wheels, and how high the carrier deck is, compared to that little figure by the rear wheel.


Now note all the above on this take.


While I don't follow any one specific 1/1 prototype crane for this build, I do try to stay within "typical" parameters. I do lean heavily on Link Belt and P&H influence. Call it "protolanced", to borrow a model railroader term.

The overall length of the carrier was shortened around 9 scale feet, (over 4"), the deck height lowered about 14 scale inches, and the width of both the carrier and the upper unit were narrowed about 10 scale inches. This brings it well into scale proportions compared to a Link Belt HC 278 H, the class of cranes I'm shooting for.

Original tires were pirated from (gulp) 3 Ertl AMT Payhauler 350 dump trucks. They'll be returned now. New smaller tires were scratchbuilt from black ABS pipe connectors and 1/4" ABS sheet, for the sidewalls. VERY messy lathe work. The treads are made from bands of bicycle inner tube for traction and quiet operation on a hard floor.








Once the sidewalls were glued in with pipe cement, They were sanded which left them a lighter flat black color, and I left them at that.



Note also in that last picture the new narrower rear equalizing suspension pieces, the access notches cut into the frame to allow wheel/axle travel, and how deep the hub detail is inset into the rim due to narrower motor-gearheads. All hard earned lowering, narrowing, and length shortening processes.
I'll post before I lose this again.

[Southgate ll]

Continuing a little bit, compare the front end of the earlier carrier to the later. I originally copied P&H carrier looks with that heavy frontal overhang, but came to dislike it. I saw a Link Belt pic on the 'net, that placed the cab more over the wheels, and just a little forward still, and thought that's the look!

Part of the overhang was room for the circuit board for the whole headlight, parking light, and flasher feature,(as can be seen in picture below) but that is now under the engine hood. Also, originally the steering servo was mounted vertically under the driver seat, forcing it in front of the axles. Then It occured to me it could be mounted horizontally between the frame rails, with a pitman arm arrangement for motion. Lop off about 3+ scale feet of bulk!

Here's a look at the 2 carrier decks. This picture, I think, best captures the difference in proportions. Over 120 square scale feet, a decent sized bedroom, was reduced from the carrier deck!


"No wonder the thing was so wide!"


The shorter motor on the left now powers the carrier drive axles,6 mounted transversely, back to back, and the drums in the upper unit. Also transverse, shaft to shaft. You can see the huge diff that would make.
Thank you for following, more later! Dan

[Southgate ll]

logging in

[frizzen]

That's such a cool crane! It definately shows that you're a modeler first, then radio control.

Where did you source the new smaller motors, or do they have part numbers?

[Southgate ll]

Thank you, Frizzen. I got the new motors on an Ebay buy it now source. Type in motor gearheads and all kinds of stuff comes up. The motors in the upper unit drums are 6v, rated at 20 rpm... I shoulda gone with 30 but they're livable. They are really powerful and have great torque. They are 25mm around. I ordered them right when the covid thing really took off in the U.S, but they got here in decent time.