We finally made a measurement box (nothing clear or fancy just hopefully close enough to size) to make our HOP2IT II design legal and to register it. We had been aiming to complete the box to meet the requirements for the postal event but it just didn’t happen.
Anyway it is now officially AUS308.
We began to think of another mark II but as usual we started to change everything at once. Hence HOP2IT Mark III.
Longer 326mm (there was room in the box)
Mast step 10mm forward
More changes to come.
Thank you for posting the plasns. It looks nice…
Just one thing, though, would it be possible to add some sort of reference measurement in the plan, to make sure the size is correct, sometimes PDF files change a litlle depending on PDF reader, printer setting …
Another great looking boat. As I predicted you are becoming quite prolific designer/builders. I am also glad you are keeping the flag flying for Oz. Your build log, if we can call it that, is fantastic & I hope your presence will encourage other Antipodeans to get involved. The footy scene in Oz seams surprisingly quiet to me, so keep up the good work.
I suppose you have been too busy developing this design to get some more internet course times since the close of the July event?
It seems you have another fan in Gio. I also thank you for the pdf’s. I have printed them off, & hope to find the time to build this one. I might try using 3mm depron, a material I have not used before. I’ll keep you posted regarding progress.
No we haven’t done any more serious times. We have found a group of boat modellers, mainly interested in electric and steam, that we have sailed with a couple of times. http://home.vicnet.net.au/~bmbg/Welcome.html There is one guy with a Marblehead and there are a couple of WeeNips but we have only seen one. We don’t think that we are about to convert them to Footys but they put out a couple of buoys and it is fun dodging the other boats and fighting to round the mark first. We probably haven’t been following the rules properly (at all) but it is interesting to see if you can squeeze a footy in the non-existent gap at the buoy. We just got sail number 308. We wonder if this means there are 308 Footys in OZ but doubt it. It is a very large place so you could easily never meet another Footy sailor in a very long time.
You are welcome to the design. The outlines are to size so you will need to allow for the 3mm of Depron. The only frame is placed 10mm aft of bulkhead 1. The bulkheads are only used for the design process and aren’t used in assembly.
We designed and made a number of successful indoor model planes with Depron but never found the building satisfactory or rewarding. The finish is rough at best. There are some people airbrushing designs on their models but they still look like a bit of foam. In OZ there are some very small indoor models made out of 2mm and even 1mm Depron. 2mm would seem about right for a Footy. Depron comes in white and grey here. It would be interesting to see what weight a Depron version came in at.
The other issue with Depron would be a water tight glue joint at the chines. The model planes were anything but water proof. Mainly stuck together with tape. It will be great to see what you come up with. Maybe it might even go OK in one of the events you have in the UK:)
We haven’t ignored your advice re cockpit size. It is just that our version II hasn’t got a single drop of water into it despite being out in some very windy conditions. Basically the whole hull under water. Our cover is lined with a foam rubber and then secured with two nylon 3mm screws. It is easy to take on and off and is many times better than the plastic and tape of our first version. Since it has worked once and gives good access to the gear we have given it a second try.
Hey you two - What is the weight of the combing and cover together with the screws? My combing and 4" plastic lid hatch weighs in around 5.5 grams installed. The 3" lid version is just over 3 grams. Component weight is a major factor,
Your hatch is certainly lighter than ours.
Our hatch is made of 0.4mm ply with 3mm x 6mm balsa edges.
The hatch complete with screws and foam tape weighs 9.6g.
There would need to be some combing on the deck hole anyway so it doesn’t add extra to the overall weight.
Having run out of surplus to requirements heli blades we had to make our own foils for this boat. We therefore took the opportunity to increase the span to 40mm and to make it full depth. This increased the length by 34mm to 234mm long. We made it from Western Red Cedar and encapsulated it in 3/4oz glass cloth applied with West Systems epoxy. Total weight before varnish is 11.5g which is the same as the 30mm X 200mm Trex heli blade version:)
A new mast step was made using aluminium tubing instead of brass. Also we didn’t take it to the bottom of the hull. Weight is 0.6g versus brass at 2.9g.
The new rudder tube is plastic instead of brass.
The new sheet fairlead is also aluminium instead of brass.
The hull with all fittings (no hatch) ready for painting is 29.9g compared to 44g for version II.
We are also working on a low aspect ratio rig.
We might reduce the bulb weight due to it having a longer moment arm.
Can you provide us with any more info or pictures of your hatch covers and coamings? I’m sure a lot of us would be interested in this, since Footys frequently spend some of their time underwater, especially on a broad reach or run, and a good watertight hatch is a necessity, perhaps even more so than most other classes. Do you vacu-form the hatches and coamings, do you do it yourself (what kind of equipment is needed), or have you found some that are commercially made?
Hey Bill and any other interested viewers - The hatch combing details are quite thoroughly covered on an old thread.
In short though, the 4" hatch cover is the plastic lid from a can of cocktail peanuts. The 3" cover is from a can of Pringles Potato Chips.
The combings can be made with different materials, but the concept is to duplicate the rim of the original container. I’ve used thin G-10 Fiberglass sheet but most recently I’ve been using 1/64th inch plywood. With the ply I usually cut a strip wide enough to raise the lower edge of the lid up a scant 1/16th from the deck. You will need to add enough extra width to account for deck thickness (I mount my combings through a 1/16th balsa deck structure which creates a flange to attach the decking to). I cut my strips cross-grain (easier to bend and more crush resistant in use).
The strip of ply is placed inside the original container tight against the sides (clothes pins are good clamps for this). The ply usually comes in 12" x 24" or 48" sheets. So a cross-grain strip will come up a bit short on the 4" combing. For this size I use two strips, roughly dividing the circumference in half. Once the strip is in the container mark the overlap. Cut the strip to length slightly longer than the marking. Make sure both ends are square. You should be able to force the strip into the container opening, the extra length should make it snug. You will need a 3/4" section of the same strip to cover the joint(s). I put a dab of Ca glue on either side of the joint and then press the covering strip tight against the joint. Household epoxy (not the 5 minute kind) can be used as well providing more working time to get things lined up.
The rim of the combing is made the same way. It is wrapped around the the combing and glued using Ca. Anchor one end and pull the rim strip taught as you go. The size of the rim strips is determined by cutting a strip of ply to approximately the same height as the rim on the container (slightly oversize is better than too narrow, you can always sand the whole piece to fit right once it is completed). Several layers have to be built up until the ply rim’s width matches that of the container’s rim.
This combing construction technique can be used for any size hatch lid, square ones as well provided the corners are well rounded.