Help with Walthers Crane

[Green_Elite_Cab]

Hey guys,

I recently acquired an Walthers American Crane. Its a neat model, with one troubling issue, the hook tends to "stick" to the thread. Unlike the Athearn 200 ton wreck crane, which uses meta pulleys, the hook on the walthers crane is compose of two solid plastic castings, with a "U" shaped channel cut into one. Ideally, the thread would wind through this channel as the hook is raised or lowered. I have included a part of the Walthers diagram to show the parts, which are in the lower right corner.

However, the problem on my model is that the hook like to "cling" to the thread. Initially, the piece were so tightly pressed together that I had to use a lot of force to pull the hook down to the bottom of the loop where it should hang. I split the hook halves apart and put them together again, but while I can easily tug the hook down, it requires lots of weight to actually keep it down while raising and lowering the hook.

I suspect I can spread the two halves a little further (and maybe reduce the friction a little), but do you have any suggestions for making this hook function more prototypically? Perhaps a thinner thread?

Otherwise, its a neat little crane, and I was really looking forward to putting DCC in it.

[Sumpter250]

I'm not that familiar with the Walthers crane, but I would assume that the "Thread" you speak of is literally "sewing thread", and has a lot of "fuzz".
Two things then: 1- If the hook doesn't have a separate sheave, but has one that is part of the single casting, try polishing the "line surface" of the sheave, with a larger thread " loaded" with something like "Softscrub", or an abrasive cleaner like "Comet".
This will help the thread move more easily across the sheave's surface.
2- If there is a medical supply house near you, see if you can purchase some 000 surgical suture. It's a silk braid, and would slip better than thread.

An alternate to all that would be to find a metal casting of the hook ( weight), drill out the area where the hook sheave would be, and install an actual sheave. The combination of the added weight/more flexible suture/rotating sheave, should vastly improve the look and function of the crane.

[Green_Elite_Cab]

Sumpter,

Yes, it appears to be a sewing thread, though I hesitate to re-rig the crane. It sounds like the suture material would be best though. I think there are some Laboratory and Medical distributors near me, but I've never just "walked in". I'll have to call them up.

I tried looking for tiny pulleys in model ship websites, but I had no luck.

I think its interesting that the Athearn 200 ton crane seems to work so well, even with the "sewing thread" rigging, but with metal pulleys. I'm almost considering trying to see if I can order those crane parts separately and just modify it into a similar looking hook. It seems like the hook on the Athearn crane is actually smaller than the Walthers one, so I might be able to figure something out there.

[Sumpter250]

Sounds like a "plan" to me. Have fun, and hope it goes well.

[Empirebuilder]

You may find a older Athearn 200 ton crane at a swap meet or on ebay and salvage parts off it that your looking for!

[Sumpter250]

I tried looking for tiny pulleys in model ship websites, but I had no luck.

If you haven't found anything yet, try http://www.bluejacketinc.com/, and go to "Fittings".
--------------------------------------------------------------------------------------
   
In this photo of the Schooner, the pulleys ( "Blocks" as in "block and tackle" )at the top of the head sails, are about 1/16' to 3/32", and are built up using some stripwood, and sheaves cut from .040" styrene rod. The sheave is drilled for an axle, and the sides of the block are also drilled the same size. I used "The Chopper" to cut the sheaves from the rod stock, and then used tiny peices of stripwood, the same thickness as the sheave for the top and bottom spacers. The finished block is "stropped" with a single strand of picture hanging wire, having an eye in one end, and the other end being formed into a hook.
In the case of these blocks, the lines run through them don't move, so the entire block can be glued and stropped, and the rigging lines can be pulled through the area at the "top" of the sheave. ( I ran out of commercially made blocks, and had to "get creative" to finish the schooner model ) I just may use this same method for single, double, and treble blocks in the future. The idea of starting with "sheave blanks" ( the "Chopper" allows a consistent thickness of the styrene rod slices, and they determine the rest of the block's size to be fairly consistently reproduced ) helps to set the sizes of all the other pieces used to construct the block.
after a couple of disasters, the process became easier to do, and made much better looking blocks, than the commercially available ones. I haven't tried..... YET ...... to build "working" blocks with this method I have to lose a bit more sanity before I try that.

[doctorwayne]

I didn't like the way the too-light hook hung on the thread, and created a new sheave for it by punching discs out of sheet brass and soldering them together. However, I didn't build mine to work, as there are too many other things which would need to be corrected.
Regardless of whether you want the crane to work or not, it would be wise to place some tension on the boom, either by adding weight to its outermost end or by use of a spring.
I opted for a spring, as it would be difficult to conceal much weight on the boom's tip, and would then require additional off-setting weight at the rear of the cab.

The spring is simply a piece of .015" music wire. One end is bent upwards and inserted into the bottom of the cab's floor, while the outer end is bent up and then out again, so that it rests atop the lower crossbracing of the boom. I cemented a strip of styrene on each side of it, as the built-in tension gave it a tendency to move laterally.




Wayne

[Sumpter250]

Regardless of whether or not there was something being lifted, there would always be tension on the lines that lift/lower the boom itself.
That little "spring" is a fantastic solution !

[Green_Elite_Cab]

I didn't like the way the too-light hook hung on the thread, and created a new sheave for it by punching discs out of sheet brass and soldering them together. However, I didn't build mine to work, as there are too many other things which would need to be corrected.
Regardless of whether you want the crane to work or not, it would be wise to place some tension on the boom, either by adding weight to its outermost end or by use of a spring.
I opted for a spring, as it would be difficult to conceal much weight on the boom's tip, and would then require additional off-setting weight at the rear of the cab.

The spring is simply a piece of .015" music wire. One end is bent upwards and inserted into the bottom of the cab's floor, while the outer end is bent up and then out again, so that it rests atop the lower crossbracing of the boom. I cemented a strip of styrene on each side of it, as the built-in tension gave it a tendency to move laterally.




Wayne

As it turns out, Walthers must have heard this piece of advice before, as my model actually already has such a wire built into it! Right now though, I might need to strengthen that wire.


Not surprisingly, opening up my crane to solve one problem made everything else foul up. It doesn't help that the whole thing is glued together out of the factory!

apparently, the little spool that pulls the boom up and down broke (how, I don't know), and so I tried to flip it around, but I think this now made the threads rub the wrong way or something, and now the boom has trouble lowering. I now remember why I have had any new cranes on my roster for so long!

[Green_Elite_Cab]

You guys must be psychic. I just pulled this crane apart again for the first time Yesterday. Still can't get the rigging to work right. I tried using some old sprues to keep the threads from touching each other so that they would work right, but it was of no use. I might just need to cut the string or something, and just re-arrange it.

I wish I knew why the spool broke on one side in the first place. I'm not sure I like the design of this crane.

[Mr Fixit]

Hi GEC,
About the only thing I can suggest is to checkout model crane user groups or there may perhaps be a model train mobile crane/wreck crane sub group.
You cant be the only guy to face this problem, so the solution is out there somewhere.
I do watch one guy on YT, but his clip on reeving was not really helpful , and he mostly models in 1: 50, so its like the difference between O scale and HO.
Picking up an old 200T wrecker at a swap meet does sound like a good idea, if only for a better understanding as to how they are rigged.

Mark

[Green_Elite_Cab]

Hi GEC,
About the only thing I can suggest is to checkout model crane user groups or there may perhaps be a model train mobile crane/wreck crane sub group.
You cant be the only guy to face this problem, so the solution is out there somewhere.
I do watch one guy on YT, but his clip on reeving was not really helpful , and he mostly models in 1: 50, so its like the difference between O scale and HO.
Picking up an old 200T wrecker at a swap meet does sound like a good idea, if only for a better understanding as to how they are rigged.

Mark

Its not so much the rigging as the model was.

Essentially, the way the model was out of the box was fine, except that the "slot" by the rear spool sheered off for some reason. I tried to fix this by flipping the spool over, but now that the threads cross at some point, the weight and pull of the boom spring isn't enough to lower the boom without me forcing it by hand, which potentially derails the crane, and can cause the spool to unwind on its own.

I could try to flip the spool back and find some other way to turn it, or I can cut the threads and try to swap them.

I'm pretty sure the problem is caused by unnecessary friction and binding.