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Re: New and Improved Mast Crutch Roller

Posted: Mon Aug 13, 2012 8:16 pm
by Divecoz
Far too many unnecessary cuts.. Neither labor or materials expedient..

Re: New and Improved Mast Crutch Roller

Posted: Mon Aug 13, 2012 8:34 pm
by seahouse
Au contraire, mon frère. :wink:

The cuts allow the project to be made from thinner material (1/2") -material easier, in most cases to obtain, or more likely to be on hand than a single big block of stock.

The cuts are also necessary to reduce friction and wear from scuffing. If the roller were a single piece, the smaller inner part would have to rotate at the same speed as the outer part, which would cause a scrubbing action on the side of the mast. This is a great example of transferring something from a drawing, where this might be missed by someone not in the trade, to a functioning part in the real world.

If it were made from a single piece, more material would be wasted. The individual pieces were discs cut from a flat sheet, which means that the individual discs were not much larger than they needed to be to make the part. One big piece would have resulted in more scrap on the floor. And I'm not that bald, Divecoz! :D

-Brian. :wink:

Re: New and Improved Mast Crutch Roller

Posted: Tue Aug 14, 2012 6:09 am
by Tomfoolery
Divecoz wrote:Far too many unnecessary cuts.. Neither labor or materials expedient..
Seahouse - you must have been looking over my shoulder. That's exactly what I did, and why I did it.

I had a bit of 1/2" Starboard left over from my BF50 throttle relocation project, so I cut discs a little oversized. Nested to minimize material waste, as Starboard ain't cheap. I cut them on a bandsaw, though I could have used various hole saws if I had the right sizes.

I actually minimized the number of cuts this time around, as I only had to clean them up to the design diameter, then cut a simple chamfer in the outside corners (back-to-back pairs, but reversed), a la the pic with the cardboard template. The extra groove in the OD of the outer plates (I used a small gouge, run straight into the material by eye) was to clear the nuts on the spreader bracket, and I may still take them back off and just reduce the OD to where they clear. That would make them flat, with no detail that would interface the mast. A quick chamfer on the outside edges, mostly for appearance (just a quick touch with a square nose scraper) is all it would need. Most of the work is in getting them clean and to the needed OD, and even that would go quicker with a better arbor (it's a bolt and a pair of nuts, in a drill chuck locked into the headstock).

These aren't jet engine parts, so common wood turning techniques are more than adequate, and I probably spent more time than really needed, but being a one-off, I wanted to be as close as I could. If I do a third go around, it'll go quicker, without any trial and error needed. Calipers preset for the desired OD, and templates for the profiles (as it were), make quick work of this sort of thing.

And the multiple disks are best to allow the large ones to turn slower than the small ones, as you stated. I asked around once for suggestions on materials for a new roller, and most of the suggestions were for synthetic materials, but a chunk big enough to do this work was too expensive, especially for experimentation. Half the material would have ended up as waste, too, which is pretty material inefficient, as divecoz pointed out. I was going to try some hardwoods, to work out the bugs, when it dawned on me to cut disks from the stuff I already had laying around.

Starboard has amazingly little friction rolling on a clean pin, by the way.

Re: New and Improved Mast Crutch Roller

Posted: Tue Aug 14, 2012 6:26 am
by Tomfoolery
Divecoz wrote:So what exactly was wrong with the black roller in the first post / photo????
Two things - the OD is too large, and it hits the nuts that hold the spreader bracket, and the ID is too small so the two tangs that attach the mast to the roller for trailering don't fit and I have to push the crutch a lot to make them line up with the holes in the mast.

Other than that, it worked just fine. No joke intended, as it was a huge improvement over the original, but I can never leave good-not-great alone. :D

Re: New and Improved Mast Crutch Roller

Posted: Tue Aug 14, 2012 6:51 am
by Divecoz
Thanks for the answers.. I don't have a lathe and have no intentions of purchasing one.. In fact I am selling and giving away a LOT of tools over the next few week's as we prepare to move south.. I only anticipate the need to trailer our boat a very few time for the rest of its life in our hands, so I guess I will leave all as is.. I like what you did and see the benefit of it .. Is there ANY possibility that you can produce these for others for a reasonable cost and allow for a reasonable compensation for your time?
My brother and I are contemplating ....offering a few items for sale, that many here have shown an interest in.. If In Fact.. you say you have no desire to manufacture these "rollers" ? I will present the idea to our CNC guy and get some idea as to a cost..
tkanzler wrote:
Divecoz wrote:So what exactly was wrong with the black roller in the first post / photo????
Two things - the OD is too large, and it hits the nuts that hold the spreader bracket, and the ID is too small so the two tangs that attach the mast to the roller for trailering don't fit and I have to push the crutch a lot to make them line up with the holes in the mast.

Other than that, it worked just fine. No joke intended, as it was a huge improvement over the original, but I can never leave good-not-great alone. :D

Re: New and Improved Mast Crutch Roller

Posted: Tue Aug 14, 2012 7:08 am
by Tomfoolery
Divecoz wrote:.. Is there ANY possibility that you can produce these for others for a reasonable cost and allow for a reasonable compensation for your time?
Perhaps. I'm not sure I'd be looking for much (or any) compensation for my time, and there really isn't that much work involved, and material cost is (so far) less than $15 per 'roller'. Maybe less still if I reduce the OD of the largest one, which needs a little tweeking anyway. They don't weigh very much, and don't take much room, so a flat-rate USPS box would probably be the way to go.

No matter what, I won't get rich making mast crutch rollers. :D

Re: New and Improved Mast Crutch Roller

Posted: Tue Aug 14, 2012 7:54 pm
by Crikey
I really like this modification idea! I can't tell you the number of times I've cursed out-loud manhandling the frikkin mast backwards on the stock roller!
Would there also be an inflatable/softer solution to this as well. I remember seeing, in the past, some dinghy hull rollers that you could pressurize with a basketball pump (sorry I couldn't re-reference any yet.)
R.

Re: New and Improved Mast Crutch Roller

Posted: Wed Aug 15, 2012 5:39 am
by Tomfoolery
Crikey wrote:Would there also be an inflatable/softer solution to this as well.
Not from me. :D I actually thought about trying to turn a groove into the original roller, but soft-ish stuff like that has a tendency to catch (the tool). Not enough material to start with on the original roller anyway.

I'm not sure how a softer roller would be a benefit, as the mast won't roll as easily over it. The Starboard seems to be non-marking so far, but time will tell. Not that it matters - it's better than what was there before, and my mast has lines and marks on it from the sail slides, halyards, bungies, etc. anyway, so I just don't care.

I'm thinking I'll make a small batch of them this winter (when I do most of my shop work - waiting for sailing season to return :cry: ) and sell them at cost.

Re: New and Improved Mast Crutch Roller

Posted: Wed Aug 15, 2012 5:44 am
by Crikey
OK! That's one order, north of the border....

Ross :)

Re: New and Improved Mast Crutch Roller

Posted: Wed Aug 15, 2012 6:35 am
by Tomfoolery
So noted. 8)

I'll have to check with the mods, so I don't get hauled and banished to storage on the hard, in a manner of speaking. :(

Re: New and Improved Mast Crutch Roller

Posted: Wed Aug 15, 2012 8:07 am
by windypatrick
tkanzler wrote:I'm thinking I'll make a small batch of them this winter (when I do most of my shop work - waiting for sailing season to return :cry: ) and sell them at cost.
I'm in, (order # please?) :D let me know when you have one. :) :) :)

It is neat to see the innovations within this group!

Order #2 :P

Re: New and Improved Mast Crutch Roller

Posted: Wed Aug 15, 2012 9:28 am
by fouz
Order 3.

I noticed after removing the spreaders and trying to raise the mast it only wants to flop on it side. So this is a great idea.

Re: New and Improved Mast Crutch Roller

Posted: Wed Aug 15, 2012 11:21 am
by Azzarac
Your orders are all out of order! LOL! Just remember I posted the first one on the 13th post of this thread! I'm actually going to try and make one with your diagrams, but I haven't touched a lathe in years so I don't have tremendous expectations for the turnout. :?

Re: New and Improved Mast Crutch Roller

Posted: Sat Aug 18, 2012 4:41 am
by Catigale
Usually the mast twists due to the weight of the furler on one of the spreaders..I don't think a roller will resist that force but YMMV.... :wink:

Re: New and Improved Mast Crutch Roller

Posted: Thu Aug 23, 2012 2:51 am
by 2ndWind
Ditto great job. I didn't get a mast crutch with my x can I make this out of stock material..