Scott, loving the videos. Have a notebook full of information growing with each video watched for my MLB build. Have a question. What are the angles of the knife edges on the turn fins you're using or have purchased? I have and am proficient with my mini mill and angle vise and can't get myself to pay for a $75+ turn fin that I can fabricate myself. Beveled edge goes to outside of fin? Guess that's 2 questions. LOL Recall you mentioning this but can't seem to find it. Appreciate any info you can provide. THX
Cut both the leading edge and the bottom at 9° or greater angle, but not less. I tried using a really light angle at one point in time, 7° if I remember right, but I always felt like it made it "darty". I figured that must be why submarines have a large radius nose instead of a sharp bevel. Something to think about, eh? And yes, you want to cut only the outside. The inside should be entirely flat to hold water in the turns. I did detail my reasoning thoroughly in one of the videos, but if you want to hear all that nonsense you'll have to go find it yourself! I'm glad you're enjoying the videos, and I hope your boats work well in spite of my ramblings.
@@M5PerfHydros Thanks for the reply Scott. Funny I just watched a video on submarines. Older subs had a pointy bow as they often operated more like ships having to surface to charge batteries with diesel generators. With advent of nuclear power this need went away. It was found that a round nose is quieter in the water as noise from a pointed nose bow would be picked up in the ships own sonar. Your submarine lesson for the day. LOL. Picked up some aluminum material to make my turn fin. Was talking to my boss about this and he gave me a small sample sheet of .100" AZ91D magnesium (2/3 weight of same size aluminum) he had for a job we are going to do. I'm a maintenance tech for company that does magnesium injection molding. Going to try a side by side comparison of turn fin made with each. Here's my question-just watched your 2023 Columbia Cup video. Great shots of sponsons and transom of Graham Trucking. Is there any reason my turn fin could not be made to scale size and shape of that on the full scale boat? You mentioned possibly cutting down height on HP Racing fin you mounted in video. Graham Trucking fin looked shorter but wider front to back. Do you see any performance issues on the smaller scale with short and fat as opposed to tall and skinny? Skinny act more like a hinge to pivot around? Appreciate your help as always. Thank you.-Bill
Scott, happened to watch your 2023 Columbia Cup video with great enthusiasm as you got some great shots of the Graham Trucking boat which I'm modeling with 1/8 MLB kit. Got to thinking if I'm going to fab a turn fin (below) why not do one like the scale boat? Took a screen shot of fin from video and using height of rear of sponson of GT vs known 1/8 boat got rough dimensions of full fin to scale down for fin to be fabbed. The Rattlesnake RC fin you used looks to have about 4" in the water at about 2-1/2" wide. 10 sq inches. The scale shape fin comes in at about 7.5 sq inches being slightly wider but not as deep. Would I be greatly inhibiting my ability to turn if I went with the scale shape? Being new to this not sure how the scale shape on a 10-11 lb boat works vs something at almost 7000 lbs. Appreciate any insight you can share. Thank you.-Bill
Hi Bill, You're on the right track when you consider the difference between a full size hydroplane and our models. With that said, I actually do prefer a design quite similar to the big boat fins and normally make them myself, but in this video series I was trying to use readily available parts so that anyone could easily copy what I was doing. You're quite a way off on the depth however. In the videos I did have it set quite deep, somewhere in the neighborhood of 2.75", but I quickly raised it to 2". Not every boat can get away with it that shallow, as the weight of the boat and the ride height each will have an effect. Generally, 2.5 +/- is a good place to start. Then raise it a bit at a time if you can, so long as the boat will still hold a tight, hard turn.
I recognize the turn fin came from Rattlesnake RC but could you please tell your viewers (yes you have many who are watching right now) where the 90-degree bracket for the turn fin came from? I’m pretty sure you manufactured the bracket yourself? Thanks in advance.
I normally build my own, but so that others can use the same parts that I am in this build, I got the bracket from Rattlesnake RC also. I do some modifications to it as shown in the video. If you were watching at, say, 7:30 instead of 2:30 IN THE MORNING you might have caught that part! Go to bed, watch it again after coffee, and I think you'll get a bit more out of it. But I do respect your dedication Mark!
Very nice work!! there is a lot to think about when building a hydro. Since I've been watching I've learned a lot! If I may ask, where do you get your 1/16" Baltic birch plywood?
I clean my brushes with acetone and then wipe with a paper towel or kleenex and store them upside down so any residue glues yhe hairs to tha handle . Call me cheap !
Just thought of a new gameshow. Guess what's in Scott's trash bucket. Btw, by now you know that you nailed the GoPro angle.
You don't wanna know what's in there!
Scott, loving the videos. Have a notebook full of information growing with each video watched for my MLB build. Have a question. What are the angles of the knife edges on the turn fins you're using or have purchased? I have and am proficient with my mini mill and angle vise and can't get myself to pay for a $75+ turn fin that I can fabricate myself. Beveled edge goes to outside of fin? Guess that's 2 questions. LOL Recall you mentioning this but can't seem to find it. Appreciate any info you can provide. THX
Cut both the leading edge and the bottom at 9° or greater angle, but not less. I tried using a really light angle at one point in time, 7° if I remember right, but I always felt like it made it "darty". I figured that must be why submarines have a large radius nose instead of a sharp bevel. Something to think about, eh? And yes, you want to cut only the outside. The inside should be entirely flat to hold water in the turns. I did detail my reasoning thoroughly in one of the videos, but if you want to hear all that nonsense you'll have to go find it yourself! I'm glad you're enjoying the videos, and I hope your boats work well in spite of my ramblings.
@@M5PerfHydros Thanks for the reply Scott. Funny I just watched a video on submarines. Older subs had a pointy bow as they often operated more like ships having to surface to charge batteries with diesel generators. With advent of nuclear power this need went away. It was found that a round nose is quieter in the water as noise from a pointed nose bow would be picked up in the ships own sonar. Your submarine lesson for the day. LOL.
Picked up some aluminum material to make my turn fin. Was talking to my boss about this and he gave me a small sample sheet of .100" AZ91D magnesium (2/3 weight of same size aluminum) he had for a job we are going to do. I'm a maintenance tech for company that does magnesium injection molding. Going to try a side by side comparison of turn fin made with each. Here's my question-just watched your 2023 Columbia Cup video. Great shots of sponsons and transom of Graham Trucking. Is there any reason my turn fin could not be made to scale size and shape of that on the full scale boat? You mentioned possibly cutting down height on HP Racing fin you mounted in video. Graham Trucking fin looked shorter but wider front to back. Do you see any performance issues on the smaller scale with short and fat as opposed to tall and skinny? Skinny act more like a hinge to pivot around? Appreciate your help as always. Thank you.-Bill
good info !
Thanks!
Scott, happened to watch your 2023 Columbia Cup video with great enthusiasm as you got some great shots of the Graham Trucking boat which I'm modeling with 1/8 MLB kit. Got to thinking if I'm going to fab a turn fin (below) why not do one like the scale boat? Took a screen shot of fin from video and using height of rear of sponson of GT vs known 1/8 boat got rough dimensions of full fin to scale down for fin to be fabbed. The Rattlesnake RC fin you used looks to have about 4" in the water at about 2-1/2" wide. 10 sq inches. The scale shape fin comes in at about 7.5 sq inches being slightly wider but not as deep. Would I be greatly inhibiting my ability to turn if I went with the scale shape? Being new to this not sure how the scale shape on a 10-11 lb boat works vs something at almost 7000 lbs. Appreciate any insight you can share. Thank you.-Bill
Hi Bill,
You're on the right track when you consider the difference between a full size hydroplane and our models. With that said, I actually do prefer a design quite similar to the big boat fins and normally make them myself, but in this video series I was trying to use readily available parts so that anyone could easily copy what I was doing. You're quite a way off on the depth however. In the videos I did have it set quite deep, somewhere in the neighborhood of 2.75", but I quickly raised it to 2". Not every boat can get away with it that shallow, as the weight of the boat and the ride height each will have an effect. Generally, 2.5 +/- is a good place to start. Then raise it a bit at a time if you can, so long as the boat will still hold a tight, hard turn.
I recognize the turn fin came from Rattlesnake RC but could you please tell your viewers (yes you have many who are watching right now) where the 90-degree bracket for the turn fin came from? I’m pretty sure you manufactured the bracket yourself? Thanks in advance.
I normally build my own, but so that others can use the same parts that I am in this build, I got the bracket from Rattlesnake RC also. I do some modifications to it as shown in the video. If you were watching at, say, 7:30 instead of 2:30 IN THE MORNING you might have caught that part! Go to bed, watch it again after coffee, and I think you'll get a bit more out of it. But I do respect your dedication Mark!
Very nice work!! there is a lot to think about when building a hydro. Since I've been watching I've learned a lot!
If I may ask, where do you get your 1/16" Baltic birch plywood?
It's Finnish birch that I get from Aircraft Spruce www.aircraftspruce.com/catalog/wppages/finnishbirch.php
@@M5PerfHydros thank you Scott! The 1/16" seems to be like hens teeth in Baltic.
I clean my brushes with acetone and then wipe with a paper towel or kleenex and store them upside down so any residue glues yhe hairs to tha handle .
Call me cheap !
Ok ... Cheap!