Hello! I am new to r/c boating but have about 10 years in r/c planes. I have built a 48" deep vee mono hull and am in need of some assistance with hardware selection and setup.
With my planes, i have always tried to buy hardware that will still be usable when i move up to the next, bigger plane. Id like to do the same here.
So far, I have read good things about the rcmk engines so i was thinking of using it or the rev-unlimited pro-mod engine.
My biggest concerns are with the rudder and flex shaft setup. stinger or strut? single or dual rudder? Im not going to run a clutch, so do I still need a water pump? Prop selection?
I apologize if i have posted this in the wrong forum.
Any help would be greatly appreciated.
James

go to top of page and under Magazine (under boats) there a lots of builds - reading them may help understand better

www.modelgasboats.com/Magazine_Content/Boats/


whoever manufactures the boat you want should have hardware suggestions if not post picture of boat first and ask

Don't do the " I bought all this stuff will it work ??" that never seems to work out - pick a good name hull (not eBay) and start from there and post post post

way easy to answer when we know about a specific boat or hull ...... 48 Mono is kind of general

WHat hull should be first question??

Cheers -- have fun - guys here will help - just need specific questions with a specific hull -- as many are diff

Randy

MCB

Hi James, I verry new to gas boating but did run FE, just switched to gas for autonomy reasons.I can pass along whatever little I need. First of all RCMK engines are really good, I have friends who run them and are verry happy. I my self but an RCMK twin cyl engine for my 58 Deep V. As far as quality goes they are really good for a fair price. Will last a lot longer if you mod up, than a zenoah or similar brand. For flexshaft just go 1/4", It will be the thikest and strongest assuming you are going for flexshaft. Remember that it has to be welded the flex from the shaft, no ferrule stuff it will break. the brand that Gizmomotorz, carries are one of the best. They also carry lots of rcmk watercooled engines the ones with the K30 cyl are pretty good, and deliver lots of power.

As far as stinger or strut its basically just preference no written rule about this. Usually stinger will be used for surface drive and struts for totally submerged drives, but dependes how far down you put them. In all my boats I run struts for surface drives. In general, Stingers are easier to tune up or down. But struts will generally put your prop further away letting it bite more water. At the end it will depend on your transome space, configuration, and personal preference...

Rudder: For monos it is common practice to go with a single offset rudder, to compensate for torque roll. Being that said, this can be achieved as well, by putting the shaft offset as well. Either way, I am particularly drawn to twin rudders, Al my boats have them I thik they just look cool .... So to compensate for torque roll the hole setup has tu be mounte a few degrees offset from center, (this offset vary from engine to engine, and boat to boat, you should ask the boat hull manufacter how much offset should you give to your setup. this can also be compensated moving aroud weight insede the hull (pipes, gas tank,etc)... Also personal preference. remember if your are set on racing, I am not, dual rudder will give you more drag and speed you down but will let you give sharper turns.

If you are not running clutch the water pump is useless, you will always have foward momentum letting water through your cooling system. Remember when bench testing, always make wate run through your system as well, can be achieved by the small fishtank water pumps. And never run your propeller un loaded, out of the water even if watercooled, for more than 10 or 15 sec you will burn something due to high revs.

Prop selection for a 26cc should start somwhere between a 67mm and 70 mm diameter with a 1.4" to 1.5" for pitch when using a 2 blade prop. I will aslo state that you could go with three blades but start with the same size prop and then move up according to readings, temp, revs, and speed.

Dont take my advice as written in stone, this is what I have gathered, learned, and read. So read and ask everyone you can. Go to your local boating club and ask around thats the best help you could get beacuse there will be able to see your particualr setup and give specific advise. Look for similar working setups as yours THAT ARE WORKING!!!! and copy it. Chances for you to invent something new and works are slim and at the end will drive you away from your new hobby. For starting in this hobby as you might now from planes is best to keep it as simple as possible and learn from others mistakes. Pardon my english if a made mistakes or misspeled, as is not my maiden language. Hope is all well for you and your new boat!

Thanks for the input!And I apologize for the slow reply. I was away for the holidays. The hull is one built by yours truly from a set of plans downloaded from the internet. If I can figure out how to post pics, I will do that. I understand the offset. I do similar thing with planes.
What are the advantages of a surface piercing drive versus completely submerged?
Thanks,
James

In theory advantages and disadvantages will vary with hull type. And again in theory will suit different pourposes. This is a great article I know is out there in the original source but here is the page to offshoreelectrics a great website for info and spares.
www.offshoreelectrics.com/info...-propellers.php

Be awere that when building your own hull. Take the same principle with planes for every offset and defect you will pay for later on the water, it just wont crash, but you get the idea. Good look with your new build and post if you have any question, we are here to help.

Ok. I took a few pics if this will help at all. The boat is just over 48" long and has a 13" beam.

a few more