Glen-L.com

Hello,

I'd like to build a scale model of the full size boat I'm working on - the rampage. I can't work on the boat during the winter while I'm away at school, and I thought this would be a fun way to pass the time, and a great way to plan layouts, etc.

I have full access to a laser cuter, which speeds development significantly, as I can cut everything *very* quickly. I also have access to a 3D printer, which is great for printing all of the "hardware" like engine, pump, cleats, etc. However, I have a few questions, both for the community and the lovely glen-l folks, who let's be honest, are the greatest most helpful understanding people in the world (Seriously, they are pretty awesome!)

To glen-l: I realize that for any other purpose this is a very silly question, but do you by chance have digital copies of any boat patterns? I'd be completely ok with paying for another copy (though hopefully not full price!), but it would REALLY help if I could import the frames to Solidworks - any digital format whatsoever would be amazing, even scans!

To everyone else: Building at this level, as I think about it more and more, has serious challenges. I'd like to build at 1:10 scale, to make conversions easy - but where does one get MATERIALS at that scale? I'd be fine omitting screws completely, which I think you'd have to do, but where would you get wood? Surely following scale in material size would be an impossible task, as then my plywood would be .0375 inches... less then a millimeter for the metric folk! Does anyone have any experience in this area, or answers?

Thanks guys!

Denon

Tugmyway is building a scale model flying saucer. You can find his thread in "Wood and Plywood" under "The start of a cut down flying saucer". He should be able to answer your question about wood.

Bryan

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Want to build malahini "Mona Lisa"

My wife said "If I build a boat, she's getting a divorce."

Lee Valley has Baltic birch ply in 1/16" ( .060" )

Doug

1/32 (.03125", .794mm) can be purchased at Tower Hobbies on-line. There is also 1/64 (.015625", .397mm) ply called Marvelite but I have lost the name of the supplier, probably could find it with an online search.

Also look at the wood from Aircraft Spruse. Good prices!!!

Im building a scale model Zip. The wood so far has all been bought at the local r/c hobby shop. Im going to have to order online the side/bottom planking and decking to get it in mahogany of the right thickness.

The model is about 28" It will be radio controlled with an Aquacraft EP-1 outboard

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My Zip build log...
http://www.vupilot.blogspot.com
http://picasaweb.google.com/vupilot/Chr ... O0x7SvsQE#

"Nothing screams poor craftsmanship like wrinkles in your duct tape."

Sintra is a great material to make your chine and sheer from on the model. Its very flexible but sands and glues easily. I'm switching out the brittle wood ones on my model for Sintra now.

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My Zip build log...
http://www.vupilot.blogspot.com
http://picasaweb.google.com/vupilot/Chr ... O0x7SvsQE#

"Nothing screams poor craftsmanship like wrinkles in your duct tape."

Wow guys, thanks for all the quick responses!

I went with vupilot's advice and went to my local hobby shop, as I have a fairly good relationship with them already - and to my joy and surprise, they had *everything* I needed (including scale plywood, which I recently discovered is, in my opinion, THE COOLEST FREAKING THING EVER ). Got all the materials needed to get me to where I am now - flip stage - and apparently when you scale by 10, price goes down by 100, thank god! Ended up picking 1/16 for anywhere I need 1/2 or 3/4, as it's roughly halfway between the two, and 1/32 for anywhere I need 3/8 (slightly skinnier then 3/80, but the 1/16 was the next size up and overkill/not flexible enough), all in birch. All the timbre is basswood (it was that or balsa, which seemed far too weak - basswood seems quite similar to mahagony at this scale, to be honest...just the right blend of flexibility, workability, strength, etc), and is within .5" of full scale (so at most, a 2x4 could be 1.5x3.5, or 2.5x4.5) - I figure once faired and glued and finished, any minor differences won't matter.

I'm going to e-mail Gayle and see about getting any form whatsoever of the patterns, as my set is currently locked up on an island in the middle of a half frozen lake 4000 km away. Then, convert any plywood patterns (gussets, transom, stem, etc) to dxf files and laser them out. Cut all my timbre to length and go to town!

I'll try and keep updated with pictures, but progress will be quite slow given my school work...

Thanks again for all your help guys, I can't wait to start!

Denon

Quick update - turns out I (hopefully) have all the info I need in the "notes" section of the rampage's listing...assuming the drawings are accurate, I was able to get all of the frame profiles from the "sections" drawing, and the stem profile from the first overall drawing. So, I will laser the parts tomorrow, and may begin construction on thursday. My last question has to do with scale jet pumps - I'd like to have it RC powered, ideally through a jet pump, as it would be in real life - is there ANY hope of getting a scale jet pump anywhere?

Denon

I'm going to agree with the prevuious poster who suggested Tower Hobbies . Evergreen Styreene in Washington State manufacturers sheet , patterned sheet , structural shapes and clear acetate . In addition , you can also try Plastruct.com in Los Angles . They manufacture an extensive line of archurtectural plastic materials .

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See ya on the road folks ................

There is a company that builds small jet pumps for use with 26cc gas engines...I will try to find a link to it.
Going that route, I would recommend that the minimum LOA would be no less than around 42 inches in order to handle well.


Jason

Less quick update.

Again, this is in two parts due to attachment constraints. Part 1 will be progress, Part 2 plans.

Part 1:

So far, I've lasered all of the floor timbers and gussets after converting everything to SW drawings, and dxf's. Built the frames, lasered and assembled transom and stem, cut and notched motor stringers and notched frames, made keel (it's two pieces since it's a jet), and so far have it to the point that the chines are on. Lasering the parts was a huge shortcut, but I couldn't resist - the whole thing took ~ 2 minutes, and I knew everything (like the angles) was perfect, which was good considering the numerous other shortcuts I've taken. Speaking of which, since I don't have to be in it and I don't care nearly as much about it as my real full size rampage, I'm taking a number of shortcuts. For instance, there are no uprights between the stringers and frames - just huge gobs of epoxy. I didn't even make a building form, and ahvn't really checked for levelness or squareness other then eyeing things out. I didn't use a doubler on the bottom frame members of the transom (just lots of epoxy), etc etc etc. Most worrying, perhaps, is the fairness of the chines. Since I don't really have clamps for this scale, I had to hold them by hand while they dried - thankfully, the "5 minute" epoxy I'm using from home hardware sets in around 15-20 minutes, so this wasn't *too* terrible, but I could only hold down ~2 joints a side with my hands at a time, so that's how the chine went on - this resulted in each "segment" being almost perfectly straight, with a kink between each one (at every second frame) to make up for the lack of curve. It's pretty bad, so I'm glad I'm not riding in it and really don't care how it performs!

Other then that, I've learnt that basswood and the scale birch ply behave almost identically to the full size mahogany I'm using for the real one, in terms of bend ability, etc. It's *much* harder to cut things exactly to size and shape at this scale (notches were especially hard), and you cant really sand things down if they're small because you can't get small enough peices of sand paper (for instance, I had to notch the stringers entirely with a hobby knife). FInally, I learned that the tiny serrated saw blades for hobby knives are worth thier weight in gold - it's very hard to cut even the thinnest timber with the straight sharp blade that comes with them.

Sheers and battens will be next, then some fairing, and then the planking. I'm wondering how I'm going to attach the planking...I can't exactly do it frame by frame as I did with the chines. Anyone have any ideas for this?

Denon

PS sorry for the bad quality pics - had to use my cellphone cam.

Tip from my model building. Use spring clothes pins to hold small parts in posistion while glue dries.

Part 2:

Some digging on the internet found a lovely german product called the Graupner Mini-JET Which seems about perfect for my 24" overall length. The thing's *powerful* too - check out this video for static thrust, and this one for it being used in a small boat - the thing just takes off at 40 seconds, and looks like it weighs more then mine will!

The best thing is, it has reverse, which means I *could* use a nitro(gas) powerplant...still deciding if I want gas or electric. Electric is clearly the smart choice in every conceivable way, so naturally I'll probably end up going with gas ...I was leaning towards this engine as it's max rpm is very low, almost identical to the electric motor they recommend for it, and it's extremely cheap - even cheaper then an electric plant once battery and motor control vs. gas tank are figured in! Might have to get a more aggressive impeller as I believe the gas engine's a bit torquier, but that shouldn't be hard to do. I'd also like to route exhaust out the back of the boat as it would in real life, but I'm still trying to figure out if I can prevent backflow and get it water cooled (as otherwise it would surely burn the wood)...any thoughts? And, of course, a jet-o-vator or trim nozzle would be amazing - I'll have to see if I can machine one to fit on the end of the mini jet, though that might be impossible with the reverse bucket, and the boat will probably be too light to trim up much anyways, so I may forgo this entirely.

Anyways, that's it for now...I'll post the next set of pics when it's ready for planking.

Denon

PRETTY!!!!!!!!!!!!!!!!!!!!!!!

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See ya on the road folks ................