I've been at it for the past week modifying the gantry so that it will NEVER foul the ropes again. I had every thing assembled and was raising the boom when I found out that the boom luffing drums have no holding power what so ever!! The rope suddenly jumped backwards on the drums taking all of the tension off the sheaves causing a massive tangle that I had spent the better part of three hours re-rigging the night before. It was a nightmare again. So, I decided that this would not happen again. After 25 hours of work I now think the problem is solved. Here is what I did:

The first thing to fix was the luffing drums. These did not need bolts, just some 0.040" plastic clutches to keep friction on them. They work surprisingly well...nice and tight.






Next was the sheave problem on the gantry:



The sheaves are made from steel, not brass. They were not very well made. The sides were very roughly machined... probably from using dull tooling. They had to be sanded down to accommodate the new separators, Here was the first design I made.



I didn't like the way they looked out of scale so, I made another set for the lower sheaves and, a set for the moving mast.







Here are the finished pieces.













Now I just have to re-rig the gantry and raise the boom. TM

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Tom
It's pretty sad when the only modeling tool you own is a box cutter.

If the only tool you have is a hammer, you start to see every problem as a nail. Abraham Maslow

I do really like your braking solution. Apart from the twisted booms on some of these models, the free rolling drums were the only other major flaw. With that fixed, it makes it a nice model again!

When will you start mass production of these parts???

Paul R

Great job on the sheave rope guards and friction braking addition to the drums RI CRANEMAN. keeping the rope in the sheaves is a common problem with many of these models. Your addition looks like a factory installation and will certainly curtail the aggravation many of us experience with the reeving of our models.

Really awesome fixes there RI!!!!

As was said they look factory made, might be a solution to talk to our fearless leader about and maybe send him some design pictures and it could become a standard feature on those cranes!!!

I am always tweaking my stuff for things that don't look/work right!!

I've been modifying my John Deere Highspeed Dozer so that the tracks function separately (taking out the thru axle) so that it works better while turning as one track should rotate slower than the other.

Keep up the good modifications so the rest of us can get some good ideas for stuff too!!!

Might work for my HS855 in a couple spots

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Dain

I'm a kid at heart, so I will play with any model construction vehicle from 1:87 scale to 1:1 scale!!!!

Age is a state of time NOT a state of mind!!

Tom,
You again have done a wonderful job in solving a common issue. What thickness did you use for the sheave guards? Do they make replacement sheaves in brass? Or is the thickness the issue driving you to file down the existing sheaves?

Thanks

That looks right out of the factory Tom. Another great fix. Thanks for sharing all the little projects you do.