When I started out with swing rigs I used a luff pocket. I didn’t use a separate sleeve, I made the sail a little wider and folded the material over the mast onto double sided tape. I cut a series of perpendicular cuts (darts would have been better) and folded the material over a piece at a time. This kept the wrinkles down.
When I went to McRigs which needed more luff curve, I took the easy way out and tied the sails on. This lets you adjust the individual ties as needed to match the mast bend.
To quote my mentor, Morris “You need to make a lot of sails before you make a good one.”
THOSE are not puckers, those are energisers (or turbulators) and a cunning design feature*
I feel that until you have this tuned to the last small percent they are not a hindrance at all. Rig looks good, as does the entire boat
- I’ve just realised that they are mikoyan wing fences and designed to inhibit spanwise flow.
I should not shoot my mouth off too much - I am just about to crochet a MacRig for my Razor (and therefore need to print a pic of Firstfooty’s boat - which is D*** good and sailable - I commend to you the broad tip chord of the sail (made with a thin pianowire in the mast tube ) also the loop on the end (youll have someone’s eye out with that) is a good place to tie a thin mylar streamer for a (apparent) wind indicator
Couple of pics of the Razor - red hull Boots sail, and winner Gary/Duck/blue sail - both sails are carrier bags, sorry oriented, printed low-density polyethlyene film.
The Boots sail is doubled with no mast pocket (the mast just fits in the fromt of the doubled bit) blue sail is single with a mast pocket - double sided tape, I think
A modest proposal. Does this seem workable?
Razor 08 CAN
Forgot to mention that the mast would need to be stressed into a matching curve and held there while the sail tabs are attached. I always make my sail stuck down to a board, and the mast could be held in it’s curve with drawing pins or small nails, or even just sticky tape.
Rod and others,
Thanks for the helpful suggestions. Could anyone point me to a source (or type in your own information if you are willing) of info for how to tune a sail once you have it?
Here is a typical situation for me…
Since winds here today were light and fluky I made large MacRig for the depron Razor today.
High aspect rig:
Head goes back 75mm perpendicular to luff before angle into roach.
Roach done with a spline, by eye of course
2.5mm luff curve in edge used to form luff pocket. My signature pucker (turbulator) is present but smaller.
Now tell me what I should have cut or how to get an idea of how to tension the corners (yes 420sailor the diagonal crease from clew to mast is also smaller but not gone) and or add battens to get even a reasonable foil out of it.
Sorry for all the rookie questions.
Even with the pathetic shape I had it did pretty well.
As a measure of Mac rigs, can I suggest leff length and LP (Longest Pependicular). LP is the distance from the luff to the clew at right angles to the luff.
This gives an easily calculated approximate area.
Well I had the great fortune of joining the South Daytona club for their monthly Footy race last Saturday. Paul and the gang were fine hosts and refrained from laughing (at least too my face :)) at the persistent trouble I had keeping the boat moving forward.
I think I actually finished one race. Lesson learned, have your boat sorted before you go. I had been runnning AAA batteries because it was what I had a holder for. Saturday morning I dropped the AA’s in for the first time. Big surprise, they wouldn’t fit on the CG so I had to place them aft. My poor Razor couldn’t tack to save herself and getting out of irons once entered was beyond my sailing skill. I did manage a series of very slow downwind tacks in reverse. Mostly though it served as a bright yellow and purple weathervane.
I was also greatly overcanvassed for the conditions and was busy trying to work out the balance issue so I was too lazy to set up the smaller rig. When the boat would go it went very well so at least that was some encouragement.
One thing I should have tried while I was there was bending the front of the Z wire to a less acute angle and raising the clew. This might have helped a great deal with the excessive weather helm.
On Sunday I cut a place in the bulkhead to allow the batteries to move back to the CG. The boat was back to her old self, tacking reliably at will. Oh well, maybe next month. The racing was still very enjoyable and I’m trying to force more locals (Orlando) to get get their foot out and build one. So far 2 other guys have them in the works.
My second depron hull called “Facet” should hit the water this weekend. More details to follow.
Brent, to put things in perspective, it took most of the Daytona Footy fleet several months to get their boat to any state of reliability and it took me longer. It was only after two DNF’s in very light air racing Raleigh that I realised that to win a race series you have to survive it, so make the steady boat bulletproof and you may defeat the rocketship. Tortoise and Hare is definitely a factor in Footy racing. The invite to come tune up with us on saturdays stands, then you’ll be up front for the Florida Winter Rally. email me through this site, I mis-wrote your e and got an undeliverable. Paul
I’m well into my second boat and wanted to see if people would be interested in sharing some weight info. Some of my specs follow:
Chined hull, construction is 2mm depron. 1/8 balsa used for bulkheads. 1/32 and 1/64 ply for mast support and sheet leads. Hull and deck covered in Solite film. Hull assembled using foam safe CA and low temp hotglue. I used thinned epoxy to coat the wood parts. Hull shape definitely falls into the muscle category. I’ll try something skinny soon.
Beam 6" LWL 12"
Fin 1-1/2" x 8" 13g
Rudder 1-3/8 x 4-1/4" with post 3.5g
Hull/deck (all internal structure, no radio gear or batteries) 35g
Rig Luff 18" LP 11-1/4" 12g
Total so far say 65g
AA Lithiums and holder 70g
HS 55 rudder servo 8g
HS 75BB sail servo 36g
GWS RPII4ch rec’v 6g
Any suggestions for a lighter but still sufficient sail servo? This beast is rated for 91.65 oz/in. (6.6kg/cm) at 4.8v and 113.87 oz/in. (8.2kg.cm) at 6v.
As the guys from South Daytona can attest I do have like Big Macs (rigs that is).
I intend to test her at displacements of 300-500g all up. When I float tested she sat on her lines at a whopping 600g. How about a footy with a 60" MacRig? Would it qualify for radical status?
I’d like to see how this compares to some other lightweight construction techniques.
Here’s my latest, Brent:
Target displacement was 450 grams, but I went a bit over by the time it was done. My scale’s precision is 2g.
balsa hull 26g
rig slider (still fooling around with the idea) 10g
fin + bulb 284g
batteries (lithium AA) 70g
rudder servo 8g
sail servo 24g
I think the biggest weight savings that’s easily made is switching from NiH to lithium batteries.
Don’t you just love learning things the hard way? I took my new Footy out to the local flying field Saturday morning hoping to do a little recruiting. One of the guys was very intrigued and looked it over pretty closely. Says he “Hey isn’t that Hitec 75BB a retract servo?” Now the light goes on… full 180 degree rotation lock to lock, no proportional control.
30 minutes of hacking after I returned home got it cut out. So I’m back to the Hitec 225MG. The 225BB also looks like a good option same specs plastic gears 4g lighter and $5 cheaper. In retrospect I don’t imagine the metal gear I’m buying is worth much since a sail servo shouldn’t see any shock load.
What are others using for sail control?
Brent - the answer seems to be ANYTHING, at the moment.
It may be different for All-Amurican Muscle Footys (but I suspect not) but in the UK that I have seen we use all sizes and types from standard servos down to 6gm servos (hitec 50 and 60s)
The MacRigs are well aerodynamically balanced and don’t need a huge pull to move them - we reduce the rig as the wind speed rises since heel gets unmanageable.
As you say the shock loads are not great.
FWIW my personal habit is to avoid “good” spec servos as I don’t want ball races anywhere near my boats (ther can fail by corrosion). Plain bearings are bronze and/or nylon bushes, and won’t worry about corrosion or water lubrication.
Next footy is likely to use 3.4 gm park-flyer servos since I want the narrowness. It will either work or not!