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Old 01-23-2012, 11:27 PM
Jared Jared is offline
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Join Date: Dec 2010
Location: Southwest Washington
Posts: 173
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Default Re: 1/16 Bucyrus Erie 22B-III

Quote:
Originally Posted by 9W Monighan View Post
The slewing ring measures 60''dia X 47''dia in the hook roller grooves X 9''thick.I count 64T on the internal ring and it looks to be about a 42'' PD. The pinion appears to be 16T. I don't know how you're going to cut the internal ring though. I have measurements for the A frame and the correct wire rope sizes and lengths. This IS going to be a dragline ,Correct? I can also get you some pictures and sizes of the fairlead in the spring when we have our outdoor show. The books I have show alot of details. Especially the 22-RB books.
That's great, Steve! You're a gold mine. Turns out mine is a little smaller. It scales out to 56 inches so I can make it bigger which means that the rest of the undercarriage is pretty close. I was worried I might have jumped the gun and started building too soon.
I've got a shaper that once I make a new gib for the table it should be good to go. I traded 20 hours of labor for it. A friend of mine was going to tear it apart to shake his gold separating table and I talked him out of it. The real trick will be to grind the tool to the proper profile. I think I'm going to stick with the 32 pitch 90 tooth gear, even though 24P 60-something teeth would be more scale simply because the bigger the teeth get, the higher the gear ratio gets and the harder the swing servo will have to work. The one I'm using is the slowest low-profile servo I could find and I'll still have to slow it down some.
The A-frame mesurements would be good, too. I just eyeballed it and I think I'm close but measurements can't be beat. Basically I just need to know how far it is from something like the center of rotation or the boom pins, and how high.
It will be a dragline and fairlead details would be excellent. I haven't been able to find any good pictures that show how it mounts to the deck. I know it pins to the boom foot.

Quote:
Originally Posted by modelman View Post
A scratch build and a cable machine! My-2-favorite things! I will follow this closely. I'm sure you will put a lot of work and $$ in this project but I am not sure about your decision to use servos for your drums. I don't think they will last. Gearmotors would be a better choice in my opinion but maybe you have thought this thru. Sometimes taking the easy way out will cost you in the end but I wish you luck and keep the pictures coming.
I think I'll be ok. At least I hope so. I'm using a pair of servos I already have for the hoist drums. They are Hitech HS-965MGs that are supposed to make 139 in/oz of torque and my drums have a .5 in radius so that means theoretically they should be able to lift 17.375 lbs. I think a bucket full of sand will weigh 2 or 3 lbs so I think they'll hold up. I've already got 6 or 8 hours on them in my other crane and they don't seem to be bothered any. We'll find out. If nothing else, I'll say I'm conducting research for the good of the hobby finding out how servos like this application. The servos have metal gears and dual ball bearings, plus the drums will also be supported by a shaft with two bearings on it.

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