Quick expedient chainbreaker

Warning: metal content.

Gotta trim a roller chain to length on site at the end of my dock, this for the motor drive for my boatlift. I design stuff up to a point, but don't get anal about it -- there comes a time to shoot the engineer and make something that works.

I found with Google search that cutting roller chain to length is customarily done with a "chainbreaker", saw some photos. So I made one tonight that I can use on site, got it RFN at no cost -- since the lathe, mill, TIG welder and rawstock were already at hand. (hee hee!) No drawings, just make the SOB. Turn the cranks, don' need no steenkin' CNC to make a one-off. I like turning cranks. Held a tolerance of +/- .0005 where it mattered, easy peasy with one setup and a reamer. The drillrod ram slides in the hole slick as loonshit with no wobble 'tall, not a bit of it. Making it was about as fussy as frying an egg.

Couldn't resist giving it a black oxide finish since it only took a minnit to do so.

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Reply to
Don Foreman
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Elegant! Did you heat-treat the ram? (I hope that you painted that motor)

Reply to
Tom Gardner

Take a close look at bicycle chainbreakers. They have an extra set of slots.

Once you re-connect the chain, the link will be too tight. That's what the extra slots are for, they allow you to slack the tension between the two side plates.

Another tricky point is, never drive the rivet all the way out...

And never drive it out flush with the inside, either. Leave it protuding by 1/64 inch so it re-assembles easy.

Jim

Reply to
jim rozen

I used music wire (already heat treated) for the ram.

Left the motor ugly so nobody'd want it.

Reply to
Don Foreman

Thanks! I'll just use a stainless master link to reassemble the chain. There are little detents in the posts to set the clearance between the side plates.

Reply to
Don Foreman

I wasn't trying to be picky there Don - but I made *all* those mistakes as a youngster working on bicycles, as soon as I bought a chainbreaker tool.

1) drive the pin all the way out of the sideplate. No way to recover from that one, short of throwing that link away. 2) drive the pin *flush* with the sideplate when disassembling - again, a very frustrating job of getting the pin to re-enter the link. 3) leaving the pin standing proud, so the assembly is easy, but not relieving the link before installing. That one cost me one of those nylon "simplex" derailers. *snap*! They show you how to loosen the tight link in the bike books by bending the chain side-to-side, but even that doesn't really work. The second set of slots does the job great.

I realized at the time that once I bought new tools, to *watch* an old hand using the thing for a couple of times before jumping in. As they say, the devil's in the details.

Jim

Reply to
jim rozen

Before I had a chainbreaker (found in the street) I always just ground the head off one link and punched out that pin. Replace with master link. Despite being told to never use more than one master per chain I did it often. I NEVER had a chain come apart on a bicycle or motorcycle. Lucky I suppose.

Reply to
daniel peterman

Why cant you use more than one?

Gunner

"If thy pride is sorely vexed when others disparage your offering, be as lamb's wool is to cold rain and the Gore-tex of Odin's raiment is to gullshit in the gale, for thy angst shall vex them not at all. Yea, they shall scorn thee all the more. Rejoice in sharing what you have to share without expectation of adoration, knowing that sharing your treasure does not diminish your treasure but enriches it."

- Onni 1:33

Reply to
Gunner

I thought the pins were rivets, not re-usable. Are they really pins that press fit into the rollers or sideplates or ???

I used a master link. Chain is assembled and in place, the drive is mounted on the lift and wiring is done. I need to drill one hole and insert one bolt tomorrow and then I'll push the button and we'll see ... uh... probably what I forgot or screwed up.

Dropped no tools and only one bolt in the lake today, and the big magnet I finally remembered to bring found it in seconds.

Reply to
Don Foreman

They can be reused and they press into the sideplates.

Nick

Reply to
Nick Müller

I'm not sure of your particular chain, but on all motorcycle and bicycle chains, you can break and re-make them with the same pin. They call them rivets, but really they're smooth walled pins. Take an old bicycle chain and push one all the way out, you'll see.

Jim

Reply to
jim rozen

Your knowledge is out of date, Jim. Bicycle chains now have very tight pins which make cross-chaining across a wide set of sprockets, up to 10 now.

Re-using the pins will stretch the holes and will often result in a broken chain. Shimano supplies a specially sized and hardened pin; others use a link which can be snapped open.

Ted

Reply to
Ted Bennett

This is a bicycle chain, brand new, some zippy Japanese model that is preferred by bike messengers because it's plated and won't rust. It came with a stainless master link in the box, so I used that.

Reply to
Don Foreman

The latest technology for bicycle chains, as the number of cogs in the rear increased, more than 9 on some cassettes sets. (up from 5 on a 10 speed bicycle) The space between the rear drops didn't change. so the chain plates and rollers are thinner. The only places to get space. There is less plate thickness for the rivet. There is usually a warning not to reuse a rivet that has been removed. This mean that I have to carry a master link in my tool bag, along with the chain tool that I always carry. One manufacturer pack a special rivet with new chains. In an emergency, reports on the bicycle NG mention reusing the rivet to get home and replacing with the correct method as soon as possible. PS The quick and dirty chain tool is as good as needed.

Reply to
Bill Cotton

Hmm. Ain't they heard of grease?

Mark Rand RTFM

Reply to
Mark Rand

Just don't do what they did at an old Downtown Theatre a few years ago - they were doing a total building restoration, and they had a motorized extension apron for the front of the stage that rolled out over the orchestra pit. Two 15HP 480V 3Ph motors and gearboxes mounted on opposite sides of the stage, and a large driveshaft between the two sides to keep them synchronized...

You guessed it, they didn't check the motor rotations...

Blew the motors, broke things in the gearboxes, ripped a few hundred feet of conduit off the wall, made a mess of the power panels, etc.

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Reply to
Bruce L. Bergman

Ouch!

I lucked out. The boat goes up, the boat goes down. YAY! The squall of the winch motor drives the goddamned sparrows out from under the canopy, not a bad thing at all.

Reply to
Don Foreman

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