Need help looking for a thingamajig...

[tomherrick]

I'm looking for the name of a piece of hardware so that I can search for it. All the terms I've used in Google have come up empty. After spending quite a few hours looking online I need some guidance on what to call this thingamajig.

As part of my boat redo I'm planning on a crane/davit with a mast that would pass through a sleeve in the lazarette resting on a base on the sole. Two reasons for the lazarette pass through: to use the boat structure to provide support rather than a couple of bolts through the gunwale, and to keep the inside of the cockpit relatively free of protruding hardware. The item I'm trying to find is a flange-mounted lock/clamp that would mount on top of the lazarette that the mast would pass through. When loose, the crane can be turned 360-degrees; when tightened the mast should not move under a fair amount of force.

The closest thing I have found is a flange with a set screw like this:

That just won't do to when under the mast is under much torque. I'm trying to find a fitting that would apply friction all the way around the mast, preferably operated by a lever and cam. This pedestal seat mount appears to have the kind of tightening function I'm looking for with the elongated knob on the left:

I'm relatively certain I've seen something like it before but keep coming up empty. Anybody have an idea?

[Grumpy]

I don't know if it helps but if you look here:-

http://www.c-brats.com/modules.php?set_albumName=Kingfisher&op=modload&name=gallery&file=index&include=view_album.php&page=6

You will find the davit arrangement on my Rosborough which was custom made by Brooks Marine in Anacortes WA.
It works well and can be easily dismounted for trailering.

If it is of interest I can take more pictures since the boat is sitting in my driveway surrounded by many pairs of animals waiting for the rain to go away.

Merv

[Matt Gurnsey]

All of the crab pot pullers I've seen use a fitting similar to the first one. You might contact IFS in Bellingham, ad they had about a doizen different models of pot pullers on display at the Seattle Boat SHow, and might have additional information and availability.

[thataway]

Any good machine shop can make what you want. I would want a "toggle" lever for the tightening--that way you can rotate 180 degrees, and then flip it to rotate another 180 degrees.

[Pat Anderson]

If "thingamajig" didn't work, you might try "dealie-bob"...

[tomherrick]

Or, perhaps, the ubiquitous wooger-dogger... ...it's easier to find...

I'm looking for a clamp mechanism that operates like this:



A mounting flange would have to be part of it as well. What I really need at this point are the proper terms to enable a successful search. I keep getting close or part of the mechanism, but not the whole deal. Any ideas are welcome.

[srbaum]

First of all I have enjoyed viewing your project and wish you great success as the boat should be very efficient based upon the increased length to width ratio.
I have had very good results with several past projects from a relatively small sailboat hardware manufacturer. All of their products are top notch and my several request were met with exceptional results at a very reasonable price. Give this company a call and speak to http://garhauermarine.com about your davit design and part needs...they will most likely help you.
Best regards,
Steve Baum

[tomherrick]

Thanks Steve. I appreciate your comments. There are days when I wonder what the hell I'm doing, but they're few. Next time I have one of those days, I'll re-read your comment.

I've not talked to Garhauer but have spent quite a bit of time on their Web site as well as those of their competitors. Still haven't found the specific type of hardware I want - yet...

Below is a nice lever cam action clamp that might be modified with four slots machined through to bolt it just snugly to a mounting flange. Unfortunately, the maximum I.D. of this particular item is 1.5-inches. I'll need something around 2 1/4 to 3 inches I.D. for my application. Still working on it...

[localboy]

[rogerbum]

What about using a compression fitting instead? Something more like this (scroll down until you see "Through-Wall Fittings with Compression Pipe Connections". 2 and 3" diameter fittings are available.

[tomherrick]

Hey, thanks Roger. It appears as those fittings would require a wrench to operate. I'm certain they could be made to work and really like the fact that the mounting flange isn't needed; it just violates one of my principles for this apparatus - no tools. I may have to rewrite my principles, but am trying to hold onto them for now.

[localboy]

Worth a look: http://www.mcmaster.com/#shaft-collars/=bim9sh

[rogerbum]

[tomherrick]

Thanks, localboy. McMaster-Carr carries the Rutland cam lever operated shaft collar that I like but the max size is too small. I'm likely to take the concept to a prototyping machinist here in town and have him gin me up the fitting I need.

[tomherrick]

Roger,

I wonder about loosening the fittings. I often have a tough time loosening some compression clamps, like those used for painting roller extensions. Even though I tightened them by hand I've often had to use channel locks to loosen them up. Perhaps some kind of lubricant would help with that.

You're right about the slots and fasteners and tightness of the cam operated clamp. They'd have to be tight enough to keep it from vibrating, but loose enough to allow a few thousandths of horizontal movement.

I'm going to look into both options as each has merits in its favor. Thanks for the heads up on the compression clamp alternative.

I did, however, pull the boat out of the shop on the dolly today, turn it around 360 on the driveway just to test the dolly operation and how it'll work on the pavement. All went well, better than expected actually. I'll have pics in a coupla days.