forklift to unload railcars

[hjlyuen]

Modelperry, thank you for telling me about the ITSDF standards pdf file. Your description of a forklift based on a backhoe got me Googling rough terrain forklifts. Sure enough, I found JCB, CASE, and Liftking rough terrain lifts that really look like a backhoe with steer wheels that are almost half the diameter of the drive wheels. What a surprise to me. Thanks again. Henry

[hjlyuen]

I installed the drive axle next because it is behind the mast. After that, the wheels have to be installed in order to determine the height of the fork off the ground. Meanwhile, I forget to make sure that part 3 (where the steer axle attaches to the frame) was level with part 11 (the mid body frame). So my model ending up being tail heavy. Therefore part 27 (steer axle assembly) is basically to raise the rear end of the vehicle so it will sit level on the ground. The prototype has about 13 inches of ground clearance. My model ended up with 19 inches of ground clearance. To be honest, there are other problems that contributed to the ground clearance discrepancy.

[MacSongLi]

Nice work. It would be a fantastic addition to any layout.

Gary

[Siwi]

I wouldn't fret too much about the ground clearance. It's a rather inexact thing to specify unless the precise weight of the truck and the compression of the tyres is known. Having said that, one solution would be to redesign the wheels and cut part of the circumference so that they have a flat spot underneath, which you can see in the real life photos given the weight of the vehicle.

[hjlyuen]

Siwi, thank you for your encouragement. I will post the patterns in the downloads section for whoever wants it and hopefully other paper modelers will check their alignments before gluing so he/she doesn’t end up with a ground clearance discrepancy like I did. Meanwhile, I couldn’t decide where to glue the fork on my model: raised to reach the top row of lumber on a centerbeam railcar, lowered on the ground when parked and not in use, or off the ground when carrying a load. Therefore, I built a mast and fork that could be posed in any position. For that, we need an outer rail, an inner rail, a carriage base, lift chains, and lift cylinders which turn has two parts: inner piston rod and outer sleeve. Everything is built out of cardstock or paper except for the lift chain which is a piece of sewing thread. As can be seen in the photos, the carriage base will rise when the mast is raised. However, the mast and carriage base is very fragile and easily deformed (out of square) when handled.

[Siwi]

I highly commend your efforts at moving parts! It can be difficult working out how to combine functionality with model realism when doing this. The only thought I could offer is to soak or coat parts in superglue so they are stiffer and stronger, but this might damage the printing.

[hjlyuen]

Hi Siwi, thank you for your suggestion about using superglue to stiffen small parts. My problem is accidentally crushing the carriage base between my fingers while I am focused on lifting the inner rail (using forceps to grasp part 34 between the lift cylinders). After repairing the carriage base a couple of times, I ended up leaving it at the lowered position. After four and a half months, starting from 3D drawings in Sketchup, the model is finally done when the lift rings (behind the engine radiator) were glued on. In the real world, Centerbeam flat cars are unloaded by two forklifts working simultaneously on opposite sides in order to keep the rail car balanced. As a way of giving back to the paper modeling community, I am posting the patterns for who ever wants it in the “trains and railways” section of the downloads section. If anyone need help resizing to 1:48 (O scale) or 1:24 (G-scale) fell free to contact me. At the larger scales some of the parts can be redesigned to be more robust.

[lfuente]

I agree with the CA superglue idea - my experience with paper thin balsa (essentially shavings for wingtip bows) is you don't need to saturate the material, even one side is enough. And it's better to use gel rather than liquid CA for better control. I bet you just need to get CA in the inside corners of right angle bends on the unprinted side for rigidity and minimal discoloration.

One thing I've not tried is to brush on fingernail hardener (from beauty shops or dollar stores) on the inner side of structures.

[Siwi]

This is terrific work in HO scale. There is potentially a lot of fun to be had adding weathering to this subject too.

[MacSongLi]

Very detailed work. Nice!

Gary