Which size Loos gauge? #sabre34MkII


alex.ivatchev@...
 

I am going to be moving my 34T in the near future. Before I do that, I am thinking it wont hurt to record the tension on the shroud wires. Time to buy a Loos gauge, as it makes sense to me how to use one. But apparently there are many sizes. Anyone knows what is the most universal size gauge to get? I probably need to measure the wire diameters on teh boat, or perhaps someone can save me a trip.


Peter Ogilvie
 

On Feb 8, 2021, at 3:07 PM, alex.ivatchev@... wrote:

I am going to be moving my 34T in the near future. Before I do that, I am thinking it wont hurt to record the tension on the shroud wires. Time to buy a Loos gauge, as it makes sense to me how to use one. But apparently there are many sizes. Anyone knows what is the most universal size gauge to get? I probably need to measure the wire diameters on teh boat, or perhaps someone can save me a trip.


Peter Ogilvie
 

Make that a PT-3 if you want to cover 9/32”/7mm.  IIRC the PT-3 was quite a bit pricier than the PT-2 so check your wire to see if it is 1/4”.

On Feb 8, 2021, at 3:21 PM, Peter Ogilvie via groups.io <roverhi@...> wrote:

A PT-2 covers 3/16” to 9/32”.  Wire on a T34C should be 1/4”/6mm or 9/32”/7mm at the largest.  They make a cheaper model but it’s funky to work with.  They turn up regularly on eBay if you can wait.
https://www.amazon.com/Loos-Co-PT-2-Professional-Hands-Free/dp/B0000AXNQV/ref=asc_df_B0000AXNQV/?tag=hyprod-20&linkCode=df0&hvadid=312139637973&hvpos=&hvnetw=g&hvrand=9728335933229430104&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031287&hvtargid=pla-529836895419&psc=1&tag=&ref=&adgrpid=63813709122&hvpone=&hvptwo=&hvadid=312139637973&hvpos=&hvnetw=g&hvrand=9728335933229430104&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031287&hvtargid=pla-529836895419
On Feb 8, 2021, at 3:07 PM, alex.ivatchev@... wrote:

I am going to be moving my 34T in the near future. Before I do that, I am thinking it wont hurt to record the tension on the shroud wires. Time to buy a Loos gauge, as it makes sense to me how to use one. But apparently there are many sizes. Anyone knows what is the most universal size gauge to get? I probably need to measure the wire diameters on teh boat, or perhaps someone can save me a trip.



Jeff Bartlett
 

Alex,

Glen sent me the rigging specs this summer for my ‘88 S34.

The headstay should be 9/32”, intermediates 7/32”, everything else 1/4”.

Jeff 

On Feb 8, 2021, at 6:07 PM, "alex.ivatchev@..." <alex.ivatchev@...> wrote:

I am going to be moving my 34T in the near future. Before I do that, I am thinking it wont hurt to record the tension on the shroud wires. Time to buy a Loos gauge, as it makes sense to me how to use one. But apparently there are many sizes. Anyone knows what is the most universal size gauge to get? I probably need to measure the wire diameters on teh boat, or perhaps someone can save me a trip.


Harry Keith
 

I used a Loos Gauge (the old style) on my Lightning when I was racing it.  All the sailmakers provided tuning guides based on the Loos Gauge numbers.  But a Lighting is a fractional rig, with a mast built by Zebco (on a heavy air day, that mast had so much bend, you worried about breaking it!).

But there are no tuning guides for the Sabre, and the mast is more like an I-beam than a fishing rod, so you aren't setting up for bend!

In my view, the Sabre is tuned as follows:
*  Center the mast (by halyard measurements) and get all shrouds about equal tension ("feel" is fine).
*  Put desired backstay tension on.  This does require the Loos Gauge to get to some specific pounds of  tension.
*  Adjust forward and aft lowers to give desired pre-bend (a few inches is all you'll get on this mast!).
*  Go sailing.  Adjust shrouds hard on the wind at max normal heel, and tighten until the leeward shrouds are "loose" but not "slack" (no motion, but easy to move an inch or two by hand). Any more tension than this does little for performance and over-stresses the boat.  Adjust uppers and lowers to ensure a straight and centered mast.
With the exception of backstay tension, I'm not sure what, if anything, a Loos Gauge does for you.  Note that, in the slip, you can end up with different tensions between port and starboard if there is any "natural bend" to the mast -- the focus should be "straight," not "equal tension on the Gauge," and so chasing equal tension can actually be counter-productive.

Now, the Sabre has fore and aft lowers.  This gives a fixed amount of bend.  My new boat has all shrouds in line (about a foot aft of the mast, actually).  Backstay tension, which "should" tighten the forestay(s) only does that for a bit -- and then it begins to shorten the mast!  More tension, no change in jib luff curve, but more and more mast bend.  Argh!  It makes so much more sense on a flexible fractional rig boat!

Harry



On Mon, Feb 8, 2021 at 9:28 PM Jeff Bartlett <Jhbartlett@...> wrote:
Alex,

Glen sent me the rigging specs this summer for my ‘88 S34.

The headstay should be 9/32”, intermediates 7/32”, everything else 1/4”.

Jeff 

On Feb 8, 2021, at 6:07 PM, "alex.ivatchev@..." <alex.ivatchev@...> wrote:

I am going to be moving my 34T in the near future. Before I do that, I am thinking it wont hurt to record the tension on the shroud wires. Time to buy a Loos gauge, as it makes sense to me how to use one. But apparently there are many sizes. Anyone knows what is the most universal size gauge to get? I probably need to measure the wire diameters on teh boat, or perhaps someone can save me a trip.


Peter Tollini
 

The 34 II has a double spreader rig, with a flexible spar and upper and intermediate stays, similar to !y 30 III.  I highly recommend skipping the Loos gauge and methodically setting up the rig using a guide like Dedekam's Sail and Rig Tuning, then fine tuning under sail. The set up elements are placing the masthead (center side to side, rake via forestay length (the manual or Glen can provide the design length), tensioning the upper, then intermediate stays to keep the spar straight, introducing desired bend with the forward lowers, using aft lowers to limit bend.  Without a backstay adjuster, tension the backstay to an indifferent (there is no happy) medium, then go sailing and fine tuning.
Pete



On February 8, 2021, at 10:37 PM, Harry Keith <sailor11767@...> wrote:


I used a Loos Gauge (the old style) on my Lightning when I was racing it.  All the sailmakers provided tuning guides based on the Loos Gauge numbers.  But a Lighting is a fractional rig, with a mast built by Zebco (on a heavy air day, that mast had so much bend, you worried about breaking it!).

But there are no tuning guides for the Sabre, and the mast is more like an I-beam than a fishing rod, so you aren't setting up for bend!

In my view, the Sabre is tuned as follows:
*  Center the mast (by halyard measurements) and get all shrouds about equal tension ("feel" is fine).
*  Put desired backstay tension on.  This does require the Loos Gauge to get to some specific pounds of  tension.
*  Adjust forward and aft lowers to give desired pre-bend (a few inches is all you'll get on this mast!).
*  Go sailing.  Adjust shrouds hard on the wind at max normal heel, and tighten until the leeward shrouds are "loose" but not "slack" (no motion, but easy to move an inch or two by hand). Any more tension than this does little for performance and over-stresses the boat.  Adjust uppers and lowers to ensure a straight and centered mast.
With the exception of backstay tension, I'm not sure what, if anything, a Loos Gauge does for you.  Note that, in the slip, you can end up with different tensions between port and starboard if there is any "natural bend" to the mast -- the focus should be "straight," not "equal tension on the Gauge," and so chasing equal tension can actually be counter-productive.

Now, the Sabre has fore and aft lowers.  This gives a fixed amount of bend.  My new boat has all shrouds in line (about a foot aft of the mast, actually).  Backstay tension, which "should" tighten the forestay(s) only does that for a bit -- and then it begins to shorten the mast!  More tension, no change in jib luff curve, but more and more mast bend.  Argh!  It makes so much more sense on a flexible fractional rig boat!

Harry



On Mon, Feb 8, 2021 at 9:28 PM Jeff Bartlett <Jhbartlett@...> wrote:
Alex,

Glen sent me the rigging specs this summer for my ‘88 S34.

The headstay should be 9/32”, intermediates 7/32”, everything else 1/4”.

Jeff 

On Feb 8, 2021, at 6:07 PM, "alex.ivatchev@..." <alex.ivatchev@...> wrote:

I am going to be moving my 34T in the near future. Before I do that, I am thinking it wont hurt to record the tension on the shroud wires. Time to buy a Loos gauge, as it makes sense to me how to use one. But apparently there are many sizes. Anyone knows what is the most universal size gauge to get? I probably need to measure the wire diameters on teh boat, or perhaps someone can save me a trip.