Sorry lost power for a moment. Back to set up. One main factor in adding weight for balance is pendulum weight and reaction. This is often missed by most designers. With gravity you want to be low and light and add weight for balance. This is where pendulum coefficients come in. You can control reaction direction as well balance, fine tuning performance. You can always add aero into the equation but with a dramatic surface change due to ruff seas it's impossible to find. I find that the best solution is to go with mechanical control. If you would like to know more about this delta please reach out me and keep the great videos coming. Thanks Richard Retired Engineer
Hi Scott, I'm a retired engineer just getting into RC boat racing. I just started watching your videos the last couple of months and love your attention to detail. My majors are in thermos and General Dynamics. After viewing your video on (Set Up For Speed)
I been following this build series because you are sharing SO much great info. I really appreciate that. I don't race, but knowing more always helps to get a good running boat to run around just for fun. I love understanding basics and not guessing at setups. My question is, your prop shaft angle of 1.2 degrees, is that positive or negative? Is it lifting the front of the boat(positive, right)? Or lifting the back I'm guessing...
@@chilly7261 - The short answer is that the strut is angled downward at the rear. The longer answer really wouldn't be an answer but more of another one of my guesswork/theory rants. Point being, I don't think anyone really knows exactly what the thrust pattern would be for any given prop. Is the prop thrust perfectly parallel to the hub, or does it splay out to the side slightly, or a lot? Heck, I don't know. So does a 1° strut angle lift the rear, or could it actually be pushing down? Neutral? Don't know. My goal is neutral, and at the moment, with this particular prop, I'm guessing around 1° is it. How's that for confusing the topic?
Awesome! I don’t race boats, but enjoyed watching this build. The amount and detail of set up information you shared was over the top, it all makes sense. Admire you for sharing these race secrets. I don’t care what you build next, I will be watching. Appreciate the Jaxon pics at the beginning as well. Blessings!
I’ve been dorking around with kneel down outboard hydros for quite a few years and the knowledge that you’ve laid out here is gold! Granted I don’t actively race, nor am I around people that think or speak in terms of hydrodynamics,aerodynamics , physics and such, very often leaving a void in my approach to certain tinkering. Thank you for explaining these bullet points giving me great food for thought with my old wood relics! Now I get to dig through your vids for more gold!👍😉
Tip... i sponsored Australia's fastest hydro bare foot drag boat years back when i was a spraypainter, sand the bottom with 1200W&D or a 1600 so the water beads off it and put a silicone polish on it like a Mr Sheen, as Trevor Mcgrath said to me after the first run, if it had wings it would fly, even Rain X they use on race car windows works a treat
As more of a "newbie" i cant say enough how great helpful this video is.. thank you for posting this Scott!! Btw.. NAMBA District 9 has on average of about 9-11 entries of P-LTD sport hydro and P Sport Hydro on any given race weekend. Personally i would love to see a P sport hydro build and a giveaway of that boat!! Either way im sharing this video!
I'll be honest, I don't even know what a P Sport is, but I'm guessing it doesn't have anything to do with writing your name in the snow when relieving yourself 🤣
Hi Scott. We race 1/8 scale electrics here in IMPBA D12 and D13. I do have an old 1/10 scale winged wonder still practically brand new. Could use some pointers on building it (the hull is finished and primered, but no gear has been set). I have a (gas) Blazer Backlash kit I wanna build this winter. Or we can build nothing and drink more coffee...lol. Thanks for the videos Scott. Very informative.
Definitely do the Giveaway. 1/8th FE 1990's/2000's. Build for weight, do many mods/addons/doodads, and a paintjob with a boatload of taping. Lets rock and roll dude!
A lot of these theories work on full size hydros as well. Ours would turn in really fast but the rear end would want to come around to. Moved it back so back of fin is about the balance point of the boat, way better. Also need the fin running off parallel with hull otherwise by the time you are at the end of the straight you have it full right lock. So much fine tuning that can be done. Keep up the great work.
I vote for the 1/10th scale build. I converted my old Sport 40 this year to electric and works amazing. Limited on pond sizes close by so Gasser sits on the trailer too much. The Sport 40 getting a work out and loving it. Really enjoy all your videos! Thanks
You know I’m partial to Gas Boats so my vote is for a Gas Build. The 1/10 giveaway thing would be cool, but a Gasser is what I want to see. As always Thank you 🙏 for the education. Be in touch sir.
All your videos are great to watch! I hear that "chipmunk voice" when you speed through something like mixing epoxy. I then wonder if there"s a tip we may be missing? Not our buddy Scott! He wouldn't do that! LoL Don't know if he still does but, Phil Thomas use to put in his set up notes for each boat that he sold to put the weight that was needed inside of pipe insulation and secure with zip ties. Me, I had to put the weight as far forward and down low... That's your floatation as well. Didn't understand why he was putting it in the pipe insulation... Until I found a time clock that refused to move... There's a reason cars have crumple zones!
One of Best videos yet Its right full of info. So the inner part of your boat is an airfoil which flies the boat at speed is your turn fin at the balance point of the wing?? In our planes the balance on the wing is usually the thickest part of the foil weight forward makes its landing speed faster and its safer to fly and weight rearward makes it more aerobatic and a bit squirrely to fly and land . For planes lighter is always better !!
The entire build is beautiful. Thank you for these vids and your willingness to help us. Anything you build I’ll definitely watch! The give away is an awesome idea, I would donate to the cause. Maybe put an age limit on it, give it to a younger kid possibly spark some future builders.
Hi new time watcher I really learned a lot from three videos from you thank you very much as far as the new boat I would love to see ML backlash gas Build because that is what I'm going to be building next for my second build thank you for all the knowledge I do very very appreciate it I will be watching more and learning a lot more from you thank you
Awesome information, I have used some of it to check my UL-19. Do you ever mess with catamaran boats-- I could only imagine what tips and hints you would have for them.
I've never put one of my boats on scales to actually check weight side to side, though I probably should! But yes, it is a consideration of course. I'm my builds I shift the weight slightly to the left to help offset the counter rotation effect of the engine and prop on the hull.
Sorry for all the words . For the guys who havent sheeted the bottom of the sponsons yet weight could be added by using thicker wood upfront to help balance . Your thoughts ??? When we built F1 pylon racer airplanes their minimum weight was 5 lbs . So we reinforced weak spots to bring the weight up instead of adding lead . So after we built a few and destroyed them racing we knew where we could add more material to reduce stress cracks torn out landing gear etc.!!
Yes, that's correct thinking! I hate adding "unhelpful" weight, but once a boat is finished there isn't another good option. In this build, knowing what I know now, I would definitely use heavier construction and more pour foam up front. Next time!
I have been debating on a 10th scale Oberto, got some old plans from Dave Frank that I have had forever but don't know if it would stand up to today's power systems?? But to answer your question build a 10th scale electric!!
Hi Scott, I have a Dumas Scarab 377 that I bought and built in 1979, I believe. It has a OS Max .46 nitro engine. I've always wanted to convert it over to a solid shaft. Being 60 now I think with the lack of knowledge it would be difficult at best to complete. Is this something you'd be interested in doing???
blazer marine just set a new P unlimited hydro record for IMPBA of 20 seconds 1/3 mile. Would really like to see if you could replicate that. Hull is due to be released to the public sometime this winter. P class being 4s, unlimited being any motor you want. TP 4070 CM is what was in it. Dont know KV.
I have a question regarding a gas motor and stinger setup on a vee hull. I recently picked up a vee boat with a gas motor in it. I took it all apart and noticed the hole where the stuffing tube exits on the transom, is offset to the right 3-4mm. I read it’s to help with prop walk. If I center the gas motor in the mounts and the stinger is mounted square on the transom, won’t that bind the flex cable? or do you have to bend the stuffing tube up to meet the motor AND over a little to keep it inline? I’m thinking about just centering the stinger on the transom. It has turn fins on the transom. Any help or advice would be appreciated
The flex cable is very forgiving and shouldn't have any trouble making a slight jog to one side or the other. As for me, I work very hard to ensure the my engines and struts are very well aligned. I think if I were working with that boat I would correct it instead of compromising with poor alignment
@@M5PerfHydros yea that’s what I’m thinking, it’ll be nothing to move it over where it’s all perfectly aligned. I’ve always done it that way in the past and never had an issue(not that I’ve noticed) . I’m not racing it’s just for sport.
Hmm, I suppose so, but how would you attach the string to the fin? If you tied the string around the fin I think the tension on either side might influence its balance. I like your thinking though. Keep it up!
Curious about where you located the weight in the sponson. Could it have been placed more in the tip of the sponson? It would take less weight to yield the same result. My build would shave 3oz but it does move the weight higher up. Maybe the higher CG of the weight not worth the weight saving?
It's an inertia thing. If the weight is placed near the center of rotation it has less inertia effect than if it were placed farther outboard. Imagine holding a 16lb bowling ball in your hands while you rotate the ball right/left. Pretty simple, right? You can rotate it easily and quite quickly. Now imagine holding a six foot rod in the middle, with an 8lb weight on each end while you try to swing it right/left. Aha! Hard to control, eh? Well there you go
Finnish ply in varying thicknesses from 1mm to 1/4". If you'll watch my "building an RC hydroplane" playlist you'll learn everything you'll need to know, and a lot of stuff you don't too!
Nothing that I share publicly. Many good plans are available online from Newton Marine, and really great wood framing kits can be had at ML Boatworks www.newtonmarine.com/index.php/product-category/hydroplane-plans/ mlboatworksrc.com/shop-our-products/ols/categories/rc-boat-hulls-and-kits
Sorry lost power for a moment. Back to set up. One main factor in adding weight for balance is pendulum weight and reaction. This is often missed by most designers. With gravity you want to be low and light and add weight for balance. This is where pendulum coefficients come in. You can control reaction direction as well balance, fine tuning performance. You can always add aero into the equation but with a dramatic surface change due to ruff seas it's impossible to find. I find that the best solution is to go with mechanical control. If you would like to know more about this delta please reach out me and keep the great videos coming.
Thanks
Richard
Retired Engineer
I got my note pad and taking notes. Class is in session. Thanks for sharing
Hi Scott, I'm a retired engineer just getting into RC boat racing. I just started watching your videos the last couple of months and love your attention to detail. My majors are in thermos and General Dynamics. After viewing your video on (Set Up For Speed)
I just out my dog down today man. I love that you flash Jackson at the beginning. If I had a cool channel I’d do that too. Love the videos!
Oh dang John I'm so sorry to hear that! Thank you for taking a moment to comment, even while I know you're hurting. We press on...
I been following this build series because you are sharing SO much great info. I really appreciate that. I don't race, but knowing more always helps to get a good running boat to run around just for fun. I love understanding basics and not guessing at setups. My question is, your prop shaft angle of 1.2 degrees, is that positive or negative? Is it lifting the front of the boat(positive, right)? Or lifting the back I'm guessing...
@@chilly7261 - The short answer is that the strut is angled downward at the rear. The longer answer really wouldn't be an answer but more of another one of my guesswork/theory rants. Point being, I don't think anyone really knows exactly what the thrust pattern would be for any given prop. Is the prop thrust perfectly parallel to the hub, or does it splay out to the side slightly, or a lot? Heck, I don't know. So does a 1° strut angle lift the rear, or could it actually be pushing down? Neutral? Don't know. My goal is neutral, and at the moment, with this particular prop, I'm guessing around 1° is it. How's that for confusing the topic?
Awesome! I don’t race boats, but enjoyed watching this build. The amount and detail of set up information you shared was over the top, it all makes sense. Admire you for sharing these race secrets.
I don’t care what you build next, I will be watching. Appreciate the Jaxon pics at the beginning as well. Blessings!
Thanks. I've been really enjoying your vids lately too. You might say, hooked on them. Love those waters in your area too!
I would love to see a tenth scale electric build. Love your content and instructions.
You know, I've been thinking about doing just that!
I’ve been dorking around with kneel down outboard hydros for quite a few years and the knowledge that you’ve laid out here is gold! Granted I don’t actively race, nor am I around people that think or speak in terms of hydrodynamics,aerodynamics , physics and such, very often leaving a void in my approach to certain tinkering. Thank you for explaining these bullet points giving me great food for thought with my old wood relics!
Now I get to dig through your vids for more gold!👍😉
I'm glad you found a few nuggets in my little videos. But be warned... there's probably a bit of fools gold in there too!
I appreciate the season wrapup, and the changes you'd make list. This was a great video, thank you Scott!
My pleasure!
Tip... i sponsored Australia's fastest hydro bare foot drag boat years back when i was a spraypainter, sand the bottom with 1200W&D or a 1600 so the water beads off it and put a silicone polish on it like a Mr Sheen, as Trevor Mcgrath said to me after the first run, if it had wings it would fly, even Rain X they use on race car windows works a treat
I don't disagree, and there are a lot of guys doing that with their boats. But dang man, this beautifully glossy bottom looks so stinking nice!
Really enjoyed your fine tuning knowledge. Thanks Scott.
As more of a "newbie" i cant say enough how great helpful this video is.. thank you for posting this Scott!!
Btw.. NAMBA District 9 has on average of about 9-11 entries of P-LTD sport hydro and P Sport Hydro on any given race weekend. Personally i would love to see a P sport hydro build and a giveaway of that boat!! Either way im sharing this video!
I'll be honest, I don't even know what a P Sport is, but I'm guessing it doesn't have anything to do with writing your name in the snow when relieving yourself 🤣
@@M5PerfHydros this would be a Q boat.
Love to see a 1/8th scale Vintage of newer Unlimited build.
Hi Scott. We race 1/8 scale electrics here in IMPBA D12 and D13. I do have an old 1/10 scale winged wonder still practically brand new. Could use some pointers on building it (the hull is finished and primered, but no gear has been set). I have a (gas) Blazer Backlash kit I wanna build this winter. Or we can build nothing and drink more coffee...lol. Thanks for the videos Scott. Very informative.
Gasser is on the way!
Definitely do the Giveaway. 1/8th FE 1990's/2000's. Build for weight, do many mods/addons/doodads, and a paintjob with a boatload of taping. Lets rock and roll dude!
Build the gasser!!!! Make it work!! Take us for the ride!!
I do like a good challenge....
A lot of these theories work on full size hydros as well. Ours would turn in really fast but the rear end would want to come around to. Moved it back so back of fin is about the balance point of the boat, way better. Also need the fin running off parallel with hull otherwise by the time you are at the end of the straight you have it full right lock. So much fine tuning that can be done. Keep up the great work.
Yup, water and air are still water and air, no matter the size!
I vote for the 1/10th scale build. I converted my old Sport 40 this year to electric and works amazing. Limited on pond sizes close by so Gasser sits on the trailer too much. The Sport 40 getting a work out and loving it. Really enjoy all your videos! Thanks
The people have spoken... It's a Gasser!
You know I’m partial to Gas Boats so my vote is for a Gas Build. The 1/10 giveaway thing would be cool, but a Gasser is what I want to see. As always Thank you 🙏 for the education. Be in touch sir.
Yup I know. The Gasser is leading in the poll so far. Have you voted?
@@M5PerfHydros Yes 👍 Sir!!!!
All your videos are great to watch! I hear that "chipmunk voice" when you speed through something like mixing epoxy. I then wonder if there"s a tip we may be missing? Not our buddy Scott! He wouldn't do that! LoL Don't know if he still does but, Phil Thomas use to put in his set up notes for each boat that he sold to put the weight that was needed inside of pipe insulation and secure with zip ties. Me, I had to put the weight as far forward and down low... That's your floatation as well. Didn't understand why he was putting it in the pipe insulation... Until I found a time clock that refused to move... There's a reason cars have crumple zones!
Oh my! I bet time stopped for you that day 🤣
One of Best videos yet
Its right full of info.
So the inner part of your boat is an airfoil which flies the boat at speed is your turn fin at the balance point of the wing??
In our planes the balance on the wing is usually the thickest part of the foil weight forward makes its landing speed faster and its safer to fly and weight rearward makes it more aerobatic and a bit squirrely to fly and land .
For planes lighter is always better !!
Yes, yes, and yes! You've got it exactly!
that tape love the way used it
The entire build is beautiful. Thank you for these vids and your willingness to help us. Anything you build I’ll definitely watch! The give away is an awesome idea, I would donate to the cause. Maybe put an age limit on it, give it to a younger kid possibly spark some future builders.
Exactly my thinking!
I click like immediately every time and I think you should build an electric boat ten scale
Have you seen the poll? It's tipping heavily toward a new Gasser. Go vote!
Love following your builds. 1/10 scale build would be great.
Thanks Jeff
Hi new time watcher I really learned a lot from three videos from you thank you very much as far as the new boat I would love to see ML backlash gas Build because that is what I'm going to be building next for my second build thank you for all the knowledge I do very very appreciate it I will be watching more and learning a lot more from you thank you
Blazer Marine backlash V3 that is
Thanks Ancient Arachnid! But I'm a scale model builder, so no plans to do a Backlash, at least for now
Awesome information, I have used some of it to check my UL-19. Do you ever mess with catamaran boats-- I could only imagine what tips and hints you would have for them.
Nope, not yet!
Have you ever considered scratch building your own design? What would you change/add/ delete? Maybe a Sport hydro.
My Stroh Light for example? Yes, I do my own designs!
Just found your channel, makes me want to build a wood boat.
Get after it!
Awesome video!!! Thank you!!! Build a FE 1/10 scale that would be cool! Have a great day!!
Too late! The people have spoken and we'll be building The Gasser 2.0
Hey Scott, love the videos got a question does the boat need to be balanced laterally as well?
I've never put one of my boats on scales to actually check weight side to side, though I probably should! But yes, it is a consideration of course. I'm my builds I shift the weight slightly to the left to help offset the counter rotation effect of the engine and prop on the hull.
Sorry for all the words .
For the guys who havent sheeted the bottom of the sponsons yet weight could be added by using thicker wood upfront to help balance .
Your thoughts ???
When we built F1 pylon racer airplanes their minimum weight was 5 lbs .
So we reinforced weak spots to bring the weight up instead of adding lead .
So after we built a few and destroyed them racing we knew where we could add more material to reduce stress cracks torn out landing gear etc.!!
Yes, that's correct thinking! I hate adding "unhelpful" weight, but once a boat is finished there isn't another good option. In this build, knowing what I know now, I would definitely use heavier construction and more pour foam up front. Next time!
I have been debating on a 10th scale Oberto, got some old plans from Dave Frank that I have had forever but don't know if it would stand up to today's power systems?? But to answer your question build a 10th scale electric!!
The poll is tipping toward a new Gasser... Go vote!
Pro Tip: Use a plastic bread bag closer tab & place it under the end of the tape roll, you will never have to look for or fight with it. 😀
I know, but I'm too lazy to spend the 3 seconds doing that. I'd much rather spend five minutes looking for the end! 😖
Hi Scott, I have a Dumas Scarab 377 that I bought and built in 1979, I believe. It has a OS Max .46 nitro engine. I've always wanted to convert it over to a solid shaft. Being 60 now I think with the lack of knowledge it would be difficult at best to complete. Is this something you'd be interested in doing???
Nope .. I make my videos in order to teach YOU to do it! Go for it, you'll figure it out!
blazer marine just set a new P unlimited hydro record for IMPBA of 20 seconds 1/3 mile. Would really like to see if you could replicate that. Hull is due to be released to the public sometime this winter. P class being 4s, unlimited being any motor you want. TP 4070 CM is what was in it. Dont know KV.
Tell them cowards to come up here and run with us!
I have a question regarding a gas motor and stinger setup on a vee hull.
I recently picked up a vee boat with a gas motor in it. I took it all apart and noticed the hole where the stuffing tube exits on the transom, is offset to the right 3-4mm. I read it’s to help with prop walk. If I center the gas motor in the mounts and the stinger is mounted square on the transom, won’t that bind the flex cable? or do you have to bend the stuffing tube up to meet the motor AND over a little to keep it inline? I’m thinking about just centering the stinger on the transom. It has turn fins on the transom. Any help or advice would be appreciated
The flex cable is very forgiving and shouldn't have any trouble making a slight jog to one side or the other. As for me, I work very hard to ensure the my engines and struts are very well aligned. I think if I were working with that boat I would correct it instead of compromising with poor alignment
@@M5PerfHydros yea that’s what I’m thinking, it’ll be nothing to move it over where it’s all perfectly aligned. I’ve always done it that way in the past and never had an issue(not that I’ve noticed) . I’m not racing it’s just for sport.
at what point would you adjust the fin angle verses shimming the fin mount?
Aren't we talking about the same thing?
Silly question, if you want the center of balance at the turn fin could you hang it from a string on the turn fin to see if it is level?
Hmm, I suppose so, but how would you attach the string to the fin? If you tied the string around the fin I think the tension on either side might influence its balance. I like your thinking though. Keep it up!
Curious about where you located the weight in the sponson. Could it have been placed more in the tip of the sponson? It would take less weight to yield the same result. My build would shave 3oz but it does move the weight higher up. Maybe the higher CG of the weight not worth the weight saving?
It's an inertia thing. If the weight is placed near the center of rotation it has less inertia effect than if it were placed farther outboard. Imagine holding a 16lb bowling ball in your hands while you rotate the ball right/left. Pretty simple, right? You can rotate it easily and quite quickly. Now imagine holding a six foot rod in the middle, with an 8lb weight on each end while you try to swing it right/left. Aha! Hard to control, eh? Well there you go
Great explanation. Thank you.
Perhaps a gas outrigger or a mono. Come out to Vegas for the World Cup in November
Is that race still happening??
I guess I didn’t get the memo, no World Cup this year .sorry for the confusion. Always great when it happens. 😢
Dang, I was kinda ramping myself up to the idea
any chance that RCU will start running a 1/7 scale FE class?
There's been no mention up to this point, so I guess it's up to you!
What type of wood and thickness do you use to build your boat?
Best to watch his videos in full!
Finnish ply in varying thicknesses from 1mm to 1/4". If you'll watch my "building an RC hydroplane" playlist you'll learn everything you'll need to know, and a lot of stuff you don't too!
thanks
You need to scale the eliminator up and make a gasser
Ya but how to fit the big gas motor under the tiny cowling?
Hello, I like to watch your videos, but I couldn't put a Spanish translation, I think that when you upload the video you should put this option
Ok I will try
Do you have build plans?
Nothing that I share publicly. Many good plans are available online from Newton Marine, and really great wood framing kits can be had at ML Boatworks www.newtonmarine.com/index.php/product-category/hydroplane-plans/
mlboatworksrc.com/shop-our-products/ols/categories/rc-boat-hulls-and-kits
my fayrot... in the real world!
I however would build a 1/10 scale if thats what you decide on.
The poll is tipping Gasser right now...
where can i get a cmb67
Here you go www.hobbysupplies.com.au/CMB%20Engines.HTM
gasser would be fun,
On it!
i think you need to build a modern hydro.
Naw, been there and didn't like it. The wings are such a pain!
Build a Gas Scale
Ok then, I'll do it!
The head-mounted camera made me dizzy...
Me too!
build a round nose
Say what?!?
I mean??