4 Meter mono foiler project

[yachtyakka]

Hi Doug, have you got a higher res image of the yacht?

[wind_apparent]

Wind_apparent, how far down the build track are you?

I've got about 2 months of drawing and research in, and I've ordered foam for the hull and MFD for the mold frames. I have also talked to all the suppliers I'm going to use and got estimates.

1) The front looks strong and the kingpost and triangles add a great amount of strength. The rear crossbeam to rack joint looks a little unsupported and possibly weak.

The rear bar is unsupported , but pretty stout tube, it only has to support the skipper weight and not rig load, it should be fine, its actually like 30cm shorter per side than a moth, which also uses an unsupported rear bar, never seen problems with that.......If anything I can put a crossbeam in after checking the flex.

2) The square layout may work well for the rack width adjustability but it doesn't translate to real world well. Foiling adds a new dimension and also limits fore aft movement as you have to keep the boat in the air.

after studying the RS600ff vids on you tube, and just asking questions to foilers, I have found that you hardly ever go very far forward, and "never" use the aft section of the rack, in the "real word" foilers stay in a very small area in the middle of the rack a majority of the time. for me it will be baby steps forward and baby steps back, so I plan on just optimizing my Trapeze length for that area.

3) The wide racks are fine. You don't need a tramp net - or at least I don't think so.

I don't think so either, I would really like to not use them because I would like to use the gunnel as an intermediate trap rail, and tramps would be in the way of that.

4) It may pay to mock up the layout's critical dimensions in a big garage

plywood, 2x4s, 2" PVC, and closet poles (its what I had laying around in the shed) I spent every night this week messing with that , then took 30 minutes to draw my rack last night.

I think the human dynamics and ergonomics of your design are where you really have to get things right up front. If you watch video of Bora Gulari he really self limits his smooth, controlled movement to stay within a small "box" that allows his Bladerider to work.

I watch the Sam Pascoe RS600ff vid like 12 times a day, just to study and get ideas, after the first couple tiny little steps to initiate foiling he never moves his feet till its time to tack. It seems like its all little upper body movements that keep the whole thing balanced, I could probably get away with having a 2' long rack bar (I would save a ton on carbon)

Contacting the RS600FF guys may be in order to ask about fore/aft movement requirements and how smooth the tack/gybe to rack trapeze transition needs to be.

True, if there are any of you out there, pm me



thank you again, very helpful stuff..........

[wind_apparent]

Originally Posted by Doug Lord

Sam, I used 2.375ID(60mm) with a .093"(2.3mm) wall for my cross(rack) tubes for my boat which had way more SA(182) with the shrouds attached to the forward tubes. I'd say yours were probably big enough but just barely.

keep in mind that the big crossbars (53.6mm OD) have a fairly nice length of 48.7mm OD tube running through them as well (essentially 3.8mm wall combined). My shrouds are going to be attached to the crossbars where the kingpin triangle frame meets it.

thanks for the input and Veloceraptor links...

[bistros]

I used the Imron because of faster cure time and the eventual hardness it reaches. Imron doesn't use reducer like most paints for spray application - just their own hardener.

Some folks I really respect at Phil's Foils swear by it for finish paint.

Imron is pretty evil in terms of the chemical content. You've got to have a positive pressure air system, paint booth and a good mask as well as 100% skin coverage. I didn't go near it during painting - a lot of automotive painters won't use it, even though it produces unquestionably good results.

Eric painted the boat in his paint booth using a good spray gun and compressor.

I'm very happy with the finish. No detectable orange peel and no runs.

Fairing compound? West System. I kind of have a bad memory of this as you put it on and remove 99% of it sanding, but you have to do it. After fairing and sanding we used a fair amount of Awlgrip primer to build it up again for wet sanding at 220, then 400. There were two colors of Awlgrip primer used - first grey and then white to help gauge final sanding. Almost all of the white was sanded off, and it provided a very visible indication of surface problems - you could see sanding scratches easily because of the white on grey. After sanding there was a final finishing filler pass which was used to fill any remaining problems, re-sanding at 600 wet and then the final Imron.

Eric is really good at this - I learned a lot. Eric spent a couple weeks interning with Larry Tuttle of Waterrat fame this year learning about finishing technique.If you don't know who Larry is, ask a 505 guy.

[wind_apparent]

After sanding there was a final finishing filler pass which was used to fill any remaining problems

What did you use for this?

[bistros]

Originally Posted by wind_apparent

What did you use for this?

Even after the 400 wet pass sanding down the white primer to mostly grey, it was very visually apparent when there were sanding scratches and voids. The primer did not fill everything in completely, so a very fine filler was ghosted over these areas, which were then brought up to surface level. This filler was something I had never seen before - Eric indicated that high end automotive painters and perfectionists like Larry did this to assure their finished surfaces were fair and flat. From the results it really works.

The final 600 wet rendered a very nice surface for the Imron, and probably had a lot to do with how well the paint spread and settled flat. Although it is paint on epoxy/glass over wood it looks like a Mercedes car quality finish.

I'll ask Eric what exactly the product was at this stage. It was in a squeeze tube and was a very fine paste filler. We used a soft plastic scraper for application.

--
Bill

[wind_apparent]

so, I spent another Sunday on the computer, I cant wait to start getting my hands dirty. today it was all about mold design. Got some frame sheets done for my deck mold and pretty far into my hull mold (just have to draw a stucture for my frames to go on).

Heres the pics.......

( I cant believe I got all those frames on to one 4x8 sheet)

[Chris Ostlind]

Originally Posted by wind_apparent

( I cant believe I got all those frames on to one 4x8 sheet)

I hope you are cutting those on a CNC setup and that you left the correct spacing for the tool pass.

I know this from having a very understanding software guy at the CNC shop 6 years ago who took the time to reconfig my original nest so that it would work when I started to put the thing together.

Chris

[wind_apparent]

Originally Posted by Chris Ostlind

I hope you are cutting those on a CNC setup and that you left the correct spacing for the tool pass.

I was going to do it the old school way, Kinko's and a saw, (I've seen many boats done this way, Swift solo, half the worlds moths, International Canoes,) they all seem to still get through the water alright I know CnC is more accurate and faster, and now that I think about it probably more cost effective. So on second thought I might have to make some calls tomorrow. If I did go Cnc and had to change the drawings it would not be hard, all the frames are "joined" objects, so I can just drag them around at will, would take about 10 minutes. Just for kicks, what is a good frame spacing? and what kind of file do I need to convert to?

Thanks

[Chris Ostlind]

The typical cutting tool is 1/2" in diameter minimum for this type of operation.

They should be able to accept .dwg, .dxf files for conversion to their machine software with no problem. The trick is making sure that all the curves are joined and that there are no breaks for the cut path.

If you send them the file before you show-up with the stock to be cut, you probably will not be there more than 1 hour total.

Smallish cabinet shops with full sheet CNC tables will be the most cost effective, with the bigger shops having the fastest feed rate machines. It's really good if you find a shop where the machine operator or the shop owner are boat nuts (of any kind) I've had my best experiences with that type of setup.

Also doesn't hurt to supply them with some CAD images of the project as it will tulook when completed. Most of these guys are cutting Melamine laminated particle board all day, so when someone shows-up who is making a carbon flying machine, they will get special attention.

The guys who cut my parts have renderings of my boats hanging on the wall next to the control station and a couple of them have dropped by to see how it all is going together. It makes for a fun project for everyone.

Chris

[bistros]

Originally Posted by wind_apparent

I was going to do it the old school way, Kinko's and a saw, (I've seen many boats done this way, Swift solo, half the worlds moths, International Canoes,) they all seem to still get through the water alright I know CnC is more accurate and faster, and now that I think about it probably more cost effective. So on second thought I might have to make some calls tomorrow. If I did go Cnc and had to change the drawings it would not be hard, all the frames are "joined" objects, so I can just drag them around at will, would take about 10 minutes. Just for kicks, what is a good frame spacing? and what kind of file do I need to convert to?

Thanks

It cost me around $230 to get all my (14) station molds (1/2 exterior plywood), all panels and bulkheads (3mm Okume) cut on a CNC table. When you look a the cost of your time it's a no-brainer to go this route. Nice part of the CNC process is you can mark up some registration points/holes in the CAD files and use them to help visually aligning the stations on the strongback. It's easier to trust than manual cutting. We had stringer cut outs on the stations we used for checking alignment. We also included a horizontal extension below the station that attached to the strongback. This station extension made a great frame of reference point for lining things up, as well as a good clamping point during initial setup of the stations. Once things were lined up we screwed the stations to the strongback..

The panels were "wet out" and cured with epoxy before cutting on the CNC table to help prevent edge tearing and save time later during assembly. We only had to wet out the edges after cutting.

In your case with the male plug you might want to consider wetting out the inside of the frames just to keep the moisture out of the finished plug. Not that it will be an issue for the first hull, but over time the plug may not be stable if you seal the outside surface and leave the inside to breath and absorb water. This idea may or may not have merit. Just a thought.

--
Bill

[wind_apparent]

so, talked to a friend who manages a wood shop (the one selling me the MDF and plywood), he doesn't have a Cnc, but has a good friend who has a nice machine in his spindle shop, 4x8 table, so I need to go talk to them when I have my drawings finalized. (yet one more reason to stay focused and get them done)

The panels were "wet out" and cured with epoxy before cutting on the CNC table to help prevent edge tearing and save time later during assembly. We only had to wet out the edges after cutting.

This is a good idea, I will look into it, talk to the Cnc tech and see what he thinks.

In your case with the male plug you might want to consider wetting out the inside of the frames just to keep the moisture out of the finished plug

I live in colorado so moisture isn't a problem, but if I move and I'm still using this mold I'll think about spraying the inside with a couple coats of marine varnish.

thanks for the pointers, keep em comin...


****background info****** I am making a male mold from 3/8'' Mdf, covered with a 1/4'' ply skin, microlight filler, then 9oz glass, more mircrolight, then sprayed with sandable primer. Buff a little then vac bag to it. sound good

[Chris Ostlind]

So many coats of release agent that your head swims three coats ago.

It is absolutely astounding how the most tiny of little air dents in the surface will manage to hold your part when you try to make a clean pull.

Take the kids out of the room when you pull the first part. Daddy may turn ugly.... ;-)

Chris

[wind_apparent]

So many coats of release agent that your head swims three coats ago.

Oh yeah, I almost forgot.......I am making a male mold from 3/8'' Mdf, covered with a 1/4'' ply skin, microlight filler, then 9oz glass, more mircrolight, then sprayed with sandable primer. Buff a little, than"so many coats of release agent that my head swims three coats ago",then vac bag to it

[bistros]

Originally Posted by wind_apparent

so, talked to a friend who manages a wood shop (the one selling me the MDF and plywood), he doesn't have a Cnc, but has a good friend who has a nice machine in his spindle shop, 4x8 table, so I need to go talk to them when I have my drawings finalized. (yet one more reason to stay focused and get them done)



This is a good idea, I will look into it, talk to the Cnc tech and see what he thinks.



I live in colorado so moisture isn't a problem, but if I move and I'm still using this mold I'll think about spraying the inside with a couple coats of marine varnish.

thanks for the pointers, keep em comin...


****background info****** I am making a male mold from 3/8'' Mdf, covered with a 1/4'' ply skin, microlight filler, then 9oz glass, more mircrolight, then sprayed with sandable primer. Buff a little then vac bag to it. sound good

Sounds good. About the wet out of the panels - it really helps, because if you have routed manually you know it works well in only one direction - if you move the router in the wrong direction you can get pretty bad grabs & tearouts. In a CNC table the router is fixed, but the material you are working on is still subject to the same forces. Epoxying the surface before routing reduces problems dramatically, as the surface grain is stabilized quite a bit. I'm sure there may be greater bit wear, but what does a 1/2 straight bit cost?

As well when talking to the CNC people find out clearly about how they hold down the material. Many use vacuum tables, but if they aren't high tech, make sure you know where they will be clamping/screwing down so you don't put a part where you don't want it ventilated or smooshed. I'd be a little skeptical about vacuum tables as well - you just can't afford to lose registration of your datum once the cutting starts.