Just wanted to report the question of using Transmitter with full carbon hull & deck, just completed building another AC 120 that has 2 x 245 gm hull and deck 1 x 245 carbon.
There have been reports of carbon blocking signals from the Transmitter, I did a land test where had some-one walk roughly 500 meters away and no problems, then out on the water max sailing distance reached was 400 meters attennas below deck inside waterproof box …No problems what so ever !
Transmitter is Futaba 6EX - 2.4Ghz with FASST system using dual antennas bunched together in the box (not 90 degree’s apart)
Nice, I’m looking at replacing my old futaba 40 MHz system for the Graupner mx12 HOTT…
I keep getting weird glitches every now and then sailing in the harbour in Valencia. If I sail in another spot, no problems.
I think it’s the Superyacht systems interfering…
Alan,
Some time ago, I had a CF editon Seawind - I experienced no issues using my RDS8000 (Airtronics) Radio and matching receiver with no external antenna.
Not sure if I was just lucky as at the time I was not aware of any potential for a problem. No longer have that boat, replaced it with the ABS version, at a much reduced price! Can’t say I notice any difference in the performance of the two boat, but my wallet sure feels better.
Posted a couple of pics of the old CF Seawind - one with my beloved Yamaha RTW -
Your new creation is a fine looking craft for sure! Nicely done Mate!
Boomer
Alan,
Some time ago, I had a CF editon Seawind - I experienced no issues using my RDS8000 (Airtronics) Radio and matching receiver with no external antenna.
Not sure I was lucky - at the time I was not aware of any potential for a problem. No longer have that boat, replaced it with the ABS version, at a much reduced price! Can’t say I notice any difference in the performance of the two boat, but my wallet sure feels better.
I included a couple of pictures of the CF Seawind.
Your new creation is a fine looking craft for sure! Nicely done Mate!
Boomer
Alan,Superb workmanship, once again - I don’t reckon you’ve produced a duff one yet. 2 questions immediatley come to mind; 1) Has this current (ish?) build been published as a build log on any other fora you may frequent ? 2) From what I can see of the graphics, were they achieved through lots of masking tape & then either rattle cans or spray gun with all the attendent paraphernalia, or were designs created on the pc etc and then printed out for final trim & then bonding to hull. (seem to recall Jim saying that his RedBull design gave an additional 8g / side??)Eitherway, once I can start achieving sensible workshop time (the time is getting very close!)then I’ll hopefully be able to emulate, 'tho perhaps not to quite the same standardsThat’s it 4 now, hope it’s not too disjointed - I’m currently experiencing the ‘delights’ of opiates amongst others, so hopefully not rambling too much.Thats it 4 now,Regards,Row
Row, glad to hear things are on the improve with little buzz to go with it I have not published this build anywhere, trying to wind down publishing and sail more often.
You guessed correctly about lots of masking and rattle cans but I will have final gloss coat done be professional painter.
Graphics were done by eye looking at photo’s & drawing curves with pencil until it looks right on one side of the hull. Then tape curves with electrical tape (quick & easy) overlay the side of the hull with paper and smudge lines onto the paper using pencil, finally cut the curves to use as templates on other side of the hull.
Then the fun (not) of masking for hours for few seconds painting with 12 hrs drying between coats, but the weather gods were kind to me this year, 3 days straight with near 30 C temps.
Hi Alan,
nice job as usual.
I learn reading this tread that you already made 8 AC120 models. You have put on a manufacturing yard !!
Very glad to see what you have done !
Cheers
ClaudioD
Time spent masking etc is obviously well worth it - from the photos the transition lines between the colours look incredibly sharp. Just to get things straight in my head, did you use the electrical tape as a masking for the spray painting? Sorry to ask if it’s obvious, but my head is still in some far off land with the fairies!!
Hi Claudio, I’ve only made 5 at this stage & the other three (designs we worked together) are not yet complete.
Always looking to improve with each hull, funnily enough I cannot set-up any on boats so far to sail with little lee helm (like to try it) I keep moving coupling between CLR & CE further apart.
Sorry I did not make myself clear Row, I did not want to waste time with PC with shapes then printing etc. to get it right, so just went by eye directly on the hull with pencil using curved shaping rulers and eraser, until I go it right on one side.
The electrical tape was temporary (gives raised surface) so I could trace lines onto paper to be able to transfer exact same shape from one side of the hull to the other.
The sharp lines come from two things 1) using high quality Tamiya masking tape, the usual masking tape I find paint shops here cannot give sharp lines & 2) peeling the masking tape off 10 mins after painting results in sharp lines, no tearing of dry paint.
A very easy way to add a bit of lee helm is to put a larger rudder on your boat. As you are probably finding out, you need to make substantial changes to the coupling distances to achieve very minor helm differences. The rudder size makes a substantial difference! (bigger area more lee helm, smaller more weather helm). A quick, relatively easy experiment!
Interesting topic that I have some spend on, but maybe not enough :rolleyes: no idea how many rudders I’ve made but recently got down to selection of 7 for testing over last few months, still inclusive as need different wind conditions to start comparing results with two boat testing
What I can say is increasing rudder surface by roughly 30% area has significant increase in drag and from my observations there was less influence on helm than stepping the mast.
Jon I would like to try larger rudder for lee helm and my question is how much bigger should it be ?
Apologies in advance for delayed replies, but I’m on the hop and need to run to airport.
Sorry Alan,
to put my nose in, but from the picture out of 7 rudders, 5 are almost the same and the other 2 are also similar, therefore according to my experience they are only 2 types. IMO, the first in the row should be the best in therms of efficiency, means less drag for higher lift.
A 1/4 of ellipse may offer the best compromise without forgetting the thickness from 10 to 12%.
If you wish to play with the surface dimensions to change the tuning, then it is sufficient to make smaller or larger rudders by keeping the same shape. Lee helm can also be obtained by increasing Jib surface or moving or rake the mast forward !
Ciao
ClaudioD
So far I have preference for rudders from the left #4 for medium air & # 5 for heavy air & #7 when there is only very light air around. Note the axis & angle of leading edge #7 has surprising affect on turning.
The larger rudders on the left (pic in previous post) have too much area that are noticeably slower over 50 meters, I have stepped & racked the mast as far forward as it will go and still cannot achieve Lee helm also changing boom angles but too far out start affecting pointing.
To add to the mix I have started testing exactly as you suggest, changing Jib/Main sail area ratios that has significant impact on helm balance in different wind conditions but even my largest Jib cannot induce Lee helm so far…having said that I need more time in different wind conditions before I know what I’m doing there.
I’m beginning to think Lee helm is a bit of a myth
Alan,
generally skippers do not like lee helm because is dangerous on real boats.
Is also not recommended to have a tilted leading edge since it produce more lift at the stern and consequently a nose down !
ciao
ClaudioD
100% agree about ‘big boat’ skippers not liking lee helm, but somewhere on this forum I remember reading that one of the top skippers set his boat up with lee helm,one of the reasons being that if he was in the middle of a pack approaching windward mark (and therefore had no clear view of his boat) having lee trim meant that he was less likely to put his boat in irons. Seemed like good logic when I read the reasoning, even if it was counter to everything experience has taught me!
Alan,
Quite surprised to see your ‘heavy wind’ rudder had such a low aspect ratio - I know you’ve done a lot of experimentation but I can’t help thinking that the greater chord coupled with the same or greater depth than the others would give better control. My thinking is entirely from ‘big boat’ experience - I still have nightmares about a delivery trip I did once, a 52 foot shoal draft boat with centre board and hence shallow rudder. Once the wind got up helm input made little or no difference to heading, I ended up lashing the helm just to leeward and steered using the sails which made for an exhausting trip. As you indicated though, the only real test is with a two boat system - then time will tell.
I have not published this build anywhere, trying to wind down publishing and sail more often.