IOMICA Forum

Wow, I have just had a play with this software and it appears to be very good although I am still getting to grips with it. The only problem I have had with it is that it calculates displacement in Kg which is not really accurate enough. Very good starting point for new designs however

Chris

What are you guys using Hi Anders I would not consider myself an expert builder but I have recently made a hull using 2 layers of 165g/m2 cloth with both layers at 90 degrees. I do not post cure other than puting the hull and mould in a warm (35-40) cupboard for a few days and the hull appears stif...

Hi Robert I have built fins in a similar manner to yourself so I am not sure if I can give you much advise. I have tried vacuum bagging the carbon onto my fins. This has the benefit of removing any excess resin and improving the surface finish. However I have recently tried making a rudder in two ha...

On my boat I want to have each rig set up so that the main booms are different heights off the deck. However Rule C7.4 States that the lower measurement band has to be between 60 and 100 from the deck limit mark and within these limits, the variation in height of each rig is + or - 5mm. Does this me...

I think that I may have gone off at a tangent! I have never made any sails using slits but as I read the proposal it appears that a slit could extend from the leech to say 1mm from the luff and as many slits could be inserted as one wants. A slit of this type would be hard to distinguish from a seam...

Robert has highlight some very interesting issues and I am quite frankly amazed after reading through his issues that the proposal is been considered. Making sails using slits would appear to allow a sail maker to make a suite of sails that would be superior to the standard panelled sails. Roberts s...

Lester has a point about antenna length. From my limited understanding of RF everything he says is right however I have installed a few wireless hotspots at work. Which also operate on 2.4Ghz and when I measured a couple or wireless hotspot antennas I found they were even shorter at 3.2â€

I have only ever used the 5735 so my comments are based on what have read and people I have spoken to rather than actual experience. As I understand it the 5745 has replaced the 5735. My 5735 was very good until my boat got into trouble and it melted possibly due to it being stalled or perhaps water...

There seem to be a few sail makers offering sails with a pocket luff on the main to enable a jack line to be used. What advantage does this provide over more conventional sails?

Aluminium fins are allowed there is a boat at our club with one

Hi Charles You have given me some concerns. As I understood the rules it is legal to permanently adhere fittings to spars. I have already done this on one of my boats! I am also building some new rigs where it was my intention to fix some fittings on the booms using epoxy and carbon fibre tow. I und...

Hi Andrew It depends on how big your wallet is. The standard servos appear to work OK but the servo horns they come with are a bit weak and can flex. I use a Hitec HS475. This servo is ball raced and slightly higher torque but extremely intolerant to water. A lot of people appear to be starting to u...

Hi James Complex question! Current thinking appears to be to place the max rocker and consequently the fin in the middle with almost straight lines to the stem and stern. This can be seen in designs like the Erica and Stealth. If you move the point of maximum fullness further forward trying to achie...

The sails are probably the biggest contributing factor to boat speed so I would expect that replacing the stock sails would lead to a big performance increase. However you will almost certainly have to move the mast aft. Typically an IOM has its mast 20mm forward of the leading edge of the fin and I...

I have researched sail making further and looked at the previous thread. Unfortunately the urls no longer work. I have found Frank Bethwaite’s High Performance Sailing and Larry Robinsons excellent booklet very enlightening and it appears that the shape at the head of the sail and the distribution...

Hi I expect they are all 1000 long, :D max beam is interesting and I also think it is interesting to know the: distance the mast and fin are from the bows hull draught and beam on w/l (bit tricky to measure) lead length fin and rudder dimensions rig dimensions ie where shrouds attach, spreader posit...

Can you post here some of the links where i can find the fiber glasse's / epoxy's ??? You could try: http://www.cfsnet.co.uk http://www.fibretechgb.co.uk for laminating supplies. I have used them both and found them to be very good. If you intend to use foam to make a mould you will have to use epo...

Great site

I’m viewing it using IE6 at 1024 x 768 and a lot of pages have a horizontal scroll bar which I find slightly annoying

Cheers

Chris

- Is it possible to buy the keel and rudder too!? I never worked before with materials like Fiber Glass and other "modern" materials that are used on boat construction... Any alternatives!? Is it possíble to build an 100% wooden boat Most rc yachting suppliers are able to supply all of the bits yo...

I am considering trying to make my own sails and am wondering how best to go about it. After reading about making sails with blocks I am wondering what the best way of doing this is. My questions are: Do I need to make a different block for each seam? Does the lowest seam need any curve inserting or...

I am planning on making a ball raced gooseneck for my new boat and the method I am considering doing it in will IMHO streach the rules. So I would like your advice and comments before going to the trouble of making it and presenting it to my club measurer. My specific questions are: Can I make a goo...

Does anyone know where I can get one of these?

http://www.hitecrcd.com

Hitec HSR5995TG
25kg torque
0.15 sec
180 degrees
62g
40 x 20 x 37

Could this be the ultimate sail servo servo?

I’d like to challenge your idea of building a foam IOM Foam is a good material to work with but the rules state that the hull may not be constructed out expanded foamed or a honeycombed material. Therefore a foam hull would not be allowed. However if it were the volume of an IOM is about 0.02m3 (g...

Hi James You have posted quite a few questions here which challenge current IOM practice. This is a good thing and if you believe strongly I would encourage you to try them. After all nothing ventured nothing gained. However: Some may consider IOMs twitchy when pushed hard but you don’t want a boa...

Ed, The Hitec 815 is easily up to the job and I will be using it in preference to 5735 in my next IOM. It is used by many sailors at my club and none of them have any problems sailing under any wind conditions. Some even use the 715 which even cheaper and lighter. The setup you refer to is ideal and...

I was wondering how to achieve a smooth surface when hulls are manufactured using the vac bagging technique. When I have experimented with vac bagging I always get creases and a slight surface roughness?

Many thanks


Chris

Nice good looking boat. Hope it proves successful

You surprise me about how well a flat plate works. A flat plate fin of 6mm would be much stiffer than a foil section fin of the same width. Therefore would it be possible to make a flat plate fin of say 4mm thickness as strong as a foil section of 6mm. Could it be possible that that the thin flat pl...

I was recently discussing fin thickness and one of the opinions was that once you get below 9% the reduction in drag is so minimal that the disadvantages don’t make it an attractive proposition. The main disadvantages being; the loss in fin stiffness, and the reduced lift that the fin produces red...

Ralph has highlighted a good point and made me question the benefits of the rules governing construction material. Clearly this rule is intended to stop the use of carbon fibre or Kevlar but it could potential stop Jorge building a unique, attractive boat that I don’t think would have any competit...