6' Home built Chain Saw Engine boat!!!!

6' Home built Chain Saw Engine boat!!!! (Full Version)

All Forums >> [RC Boats] >> Speed - RC Gas Boats

Message

lmopar69 -> 6' Home built Chain Saw Engine boat!!!! (4/22/2004 5:30 AM)
Ok, I am finally back from Iraq and can finish my insane project. Some people had asked for pictures of my frankenboat thing before I left and I never got the chance to post them. Now here they are. My real question is if it will work! Who knows. Wont be perfect by far, but Im havin fun makin it. Now remember, I have/had ZERO experience with boats of any kind prior to starting this. I did NO research at all. Just started throwing junk from my garage together to see if I could make a R/C boat out of some junk and a chain saw engine. So far it has come along ok. I do know it floats level with the engine in it. That surprised me! May or may not acctually move under its own power when its done, who knows. Like I said though, Im havin fun! It started out as 3 chunks of plywood cut to make the basic shape. Then filled with window type sealer foam, then covered with fiberglass mat and lots and lots of resin. Still have lots of sanding to do and fill in the low spots with more resin. I learned that the foam does not take kindly to fiberglass resin. It kinda melts. Oh well, it will work out in the end. The motor is a Poulan 33? cc chain saw motor. It runs excellent. The drive shaft is a hunk of brass I had machined down to fit the clutch. Its supported by two go kart axle bearings. The prop was donated to me by a marina when I was stationed at Ft. Eustis, VA. Im sure the prop is too big, but hey, it was free, what the heck. Fine tuning to come later, I wanna drive the dang thing. The biggest problem Ive had so far is mounting the engine. The first way I did it was not secure enough and it vibrated/ripped itself loose running on the table in the garage. So, off to plan B. Dont know what plan B is yet though. We will see. After that, I gotta figure out how to steer the thing. I have ideas, lets see if any of them will work. I would love to hear everyones comments on this thing. Good or bad, cuz no matter what anyone says, Im still gonna try my own ways first. Why? Cuz I can! Ha! Anyway, check it out.

OLD_SLOW and in the WAY -> RE: 6' Home built Chain Saw Engine boat!!!! (4/22/2004 12:56 PM)
First and foremost thank you for your service to our great country i like your attitude I saw a tee shirt with a bradley fighting vehicle on it and it said " it might hurt but it "WILL" go in ok boat stuff now...... you might try picking up the mount points for the bar or the handle on the saw for mount points. as far as a prop goes an octura 482 is more what your lookin for. normally a 1/4" flex shaft is used for a driveline and that runs in a close fitting brass tube good luck dude keep us posted here is a link to a dutch boat site that is very helpful and has loads of pics they have an english language version too XTREME RC BOATS

lmopar69 -> RE: 6' Home built Chain Saw Engine boat!!!! (4/22/2004 1:11 PM)
Thanks. The Army is a job you have to do cuz you love it. Luckily, I do. A year over there sucked. I hate being away from my wife and 3 kids that long, but they are very understanding. Thats the hard part. The mortars bombs and gun fire aint nothing compared to missing your kids and wife. You would think that after 11 years of it I would get used to it, you never do. Thanks for the support! Help our guys out over there, adopt a soldier at www.operationac.com believe me, it DOES make a difference!!!! The flex shaft sounds like a good idea, but getting it to attatch to the clutch would be interresting. The hole on the clutch bell is about a 1/2" in diameter. As far as the prop, where could I get one and what would it cost? Also, this thing weighs quite a bit as Im sure you can imagine. roughly 40 lbs. Thanks for the help, ideas and support.

skoda450 -> RE: 6' Home built Chain Saw Engine boat!!!! (4/22/2004 6:58 PM)
From your pics and comments you are a "build it yourself" kind of guy, like me, so here are my thoughts. You have a great start. FPS has the right idea on the prop. Since you have lots of weight, you don't want too much pitch in the prop but it should be big enough to push it with some authotity. The propeller drive componants are the most critical part of the system. My advice would be to buy a 1/4" prop shaft, drive dog, needle bearing strut, and 1/4" flex drive coupling (which connects the flexable drive cable to the prop shaft) and 1/4 flexable drive cable. The items are available from Octura, Marine Specialties or Warehouse Hobbies on line. The rudder, mounting hardware, and stuffing box you can make from aluminum angle stock, brass tubing and sheet stock. I found 1/4" ID Oillite bronze bushings (available from the local hardware store) work well to support both ends of the flexable shaft soldered in the brass tube stuffing box. Coated well with lithium grease they do not allow water to leak in. The shaft connection to the motor will be a bigger challenge since the chain saw motor you are using did not connect to a shaft of any kind. You are going to have to get creative for this solution. Investigate the weedwhacker method and see if you can adapt some of it's componants to your chainsaw motor for the flexable cable connection. Good luck. Get back to this forum with your progress.

XxXnTk -> RE: 6' Home built Chain Saw Engine boat!!!! (4/22/2004 7:14 PM)
You said you were stationed at Ft. Eustis? i live in Yorktown, used to swim on FTE, Fort Eustis's Swim team, funny :)

lmopar69 -> RE: 6' Home built Chain Saw Engine boat!!!! (4/22/2004 8:54 PM)
I looked around at warehouse hobbies. The prop isnt a bad price but man the drive and rudder systems sure are not cheap! Im going to see how it does with the 5 1/2" trolling motor prop on there that was given to me! Its not made for high speed or anything, but hey, Ive got less than $30 in this entire boat so far, and most of that was the resin and foam. The rest I either had lying around or was given to me. If I can build this thing, paint it, and run it for less than $50 that would be cool. Then, I will get silly with it and try to make it work well with some real parts. My home built drive system is heavy, has a reletivly high amount of drag and a prop that is not made to do what I want it to do. We will see. It will probably just sit there and throw water in the air! LOL. Either that or wallow out the pin holding it to the brass shaft and fall off into Milford lake! Either way, it should be entertaining. My rudder design I have been considering will be rather interresting too. Dual rudders with cabinet door hinges ect... But hey, Im still havin fun. Now if I could just get the motor to quit vibrating loose...

skoda450 -> RE: 6' Home built Chain Saw Engine boat!!!! (4/23/2004 3:56 PM)
If you have the motor hard mounted to the boat it will continue to be a problem. You need to add some vibration dampening. I use mounts from Grainger, part number 3CC11. You can see them at www.grainger.com and lookup by the part number. They are $1.97 each and may solve you motor vibration problem. Grainger has several other styles and sizes so you can see them all in the Grainger part number range from 3CC00 to 3CC19. BTW, your budget doesn't allow for a radio system. Do you have one already? Best if it's a surface frequency and currently authorized by the FCC for model use. Old airplane radio frequencys have been reallocated to other uses and you may find very unfrendly interference. 27mhz and 75mhz bands are the surface frequencies most used today. 72 mhz bands are for model aircraft only just to keep the interferance between the two uses down. Where are you going to swing this 5.5" trollong motor prop? Under the boat I hope. If you try to run it on the surface it won't work very well because it wasn't designed for that application.

lmopar69 -> RE: 6' Home built Chain Saw Engine boat!!!! (4/23/2004 5:30 PM)
Im using a radio from one of my r/c cars. It seems to be working ok so far. Ive been told I may have problems with it because of the ignition system on the motor causing interference. So far I havent had that problem while running it on the table. When the boat is in the water (just sitting of course since I havent run it in water yet) the prop sits abou a 1/2" below the surface. its at a little bit of a downward angle also. May work, may not. We'll see huh? lol After I have tried all of my original ideas for this monster, and they either work or dont, then I will probably change it to a more conventional setup like some of the other boats Ive seen online use. The budget isnt really an issue, just kind of fun seeing how cheaply I can do this and still make it work. Trying to make/create everything from parts and peices I have laying around. More for the challenge of it than anything. And if it works, well hey, even better. If it dosnt, well, time to try something else. I have some rubber laying around here, about 2" thick or so, I may cut some of it up and try that for the mounting too. The main problem is I was mounting it to a 2x4 that I bolted into the bottom of the boat before fiberglassing it. I now need to drill it out and replace it with something stronger. A hunk of metal may just do the trick. Thanks for the advice and the links. I keep saving all the info everyone gives so when my ideas all suck I can go and get the stuff Im really supposed to use and make it work right!!

lmopar69 -> RE: 6' Home built Chain Saw Engine boat!!!! (4/26/2004 3:06 AM)
Well, looks like I will get to see if this thing will move in the water tomarrow. Gonna stick it in a pond and see if it will make it accross. I remounted the motor, put in the radio gear for the throttle, mounted the fuel tank and put the prop on. There is still a lot of vibration in it but hey, who knows, maybe it will acctually make it accross the pond without self destructing. A firey crash and burn/sink would be cool to though! I ll be sure to take my digital camera/video camera with so I can let ya all see what happens too. Wish me luck. Later

Daniel Ramsey -> RE: 6' Home built Chain Saw Engine boat!!!! (4/26/2004 7:10 AM)
I love hearing about home brews! I have a bunch of 25cc weedies lying around when I was into airplanes and even a stripped downed and lightened up McCulloch 56cc chainsaw motor that I was thinking recently about using in my 1/4 scale Ryan monowing, it was just a little bit too big even for a 22lb aircraft. But I just picked up on a Traxxas NV on ebay that as soon as our lakes thaw out (yep its Alaska) I'm heading out with my 10 year old son and have some simple fun, I have some bids on two more of the Nitro Vees so we can have the same boat and setup and do some lap racing. To fastratporting, just this evening a gas rigger was up on ebay for sale, the seller had only a few bidders including myself, he said you built it? it looks to me like something my 56cc would fit in. I passed it up only because I am just starting my conversion from air to water (I hated the thought of losing my Byron STA 1/4 scale in a crash!) and it was pretty darn big. The Dumas kit "Primetime" I won on ebay last week cost me over $50 in shipping alone! Shipping has always been a headache for me so I think I'll get into building my own like a large hydro. I am going to follow this project closely, I agree vibration may be a problem. make sure to pay attention to waterproofing your electronics, I've heard of ideas from using tupperware containers to ziplock bags. If you can use some minimal expansion foam in open areas to give you some floatation in case you flip, and do a range check on how far your transmitter/reciever can operate, GOOD LUCK![;)]

lmopar69 -> RE: 6' Home built Chain Saw Engine boat!!!! (4/26/2004 1:05 PM)
Thanks for the input D.R. I used some serious Lock-tite on the motor mounting bolts last night---ok so I put epoxy on the threads, but anyway, hopefully it will keep it mounted long enough to get it accross a pond this morning. I have some home-made brackets mounted to the motor with 3 of the original screws that used to hold the motor case on. Those were the ones causing the problems of loosening. Then those brackets are screwed into a 2x4 that is bolted and fiberglassed into the bottom of the boat. We will see how long this method lasts today I suppose. I havent water proofed my electronics yet. Probably will just stick the reciever into a zip lock or something for now. Im useing an old traxxas RX, TX and servos. The one thing I dont think will ever be a problem is floatation! If you check out the pics, this thing has more foam in it than a 18 foot bass boat! Ok not really, but I think it could get hit by a hydro doing 160mph and the pieces left would still be floating! If it all works today when I "test" it. Tonight I will start on my half-a$$ed dual rudder system I have been thinking about. As I have said, no matter what, it should be fun to see what happens. Pictures to follow later today! And last but not least, stay warm up there!!! I spent a few days in AK for the Army about 4 years ago---FROZE MY BUTT OFF!!! I dont know how you do it. I hate the cold! Good luck! Thanks.

skoda450 -> RE: 6' Home built Chain Saw Engine boat!!!! (4/26/2004 2:15 PM)
Ok, now I'm jealous. It's Monday morning and I am stealing time at work to read the threads and YOU are actually out having fun. Anyway GOOD LUCK. I hope it works out for you. Even if it doesn't, I bet you will have a ball just watching what happens.

lmopar69 -> RE: 6' Home built Chain Saw Engine boat!!!! (4/26/2004 2:53 PM)
Ha ha!! Have fun at work!!! Im on leave for another 20 days!! I guess thats the good part of having to be in Iraq for a year. But hey, wait a minute... You were out playing the whole time I was over there... NO FAIR!!!

skoda450 -> RE: 6' Home built Chain Saw Engine boat!!!! (4/26/2004 8:31 PM)
You are quite correct and, if no one has told you yet, THANK YOU for your service. I am a Vietnam Vet and I know how much you have to give up to be there for all of us. But, lets not get too serious here. The most important question is "Did it float?" Pics please!!!

lmopar69 -> RE: 6' Home built Chain Saw Engine boat!!!! (4/27/2004 12:35 AM)
First, THANK YOU for your service. You were in the Army long before me. Thanks, I appreciate it. Now to the fun stuff. Like a dip-sh!* I forgot the digital camera. But I can give you a play-by-play! We pulled it out, fueled it up, and started it. Ran good like normal. I lost the shoes and socks and off to the water I went. It sat nice and level, maybe a little tilt to the left. I goosed the throttle and it died. After a restart and some carb fiddleing it ran great. I hit the gas again and off it went. SLOW!!! Shooting a nice spray of water. The prop needs to be a little lower in the water. It went about 5-8 mph and that was it. It also circles to the left pretty bad. So, with some ballast and rudders, Im sure it will be fine. Tomarrow I will build the rudder system. And next time I WILL NOT FORGET THE CAMERA!!!

skoda450 -> RE: 6' Home built Chain Saw Engine boat!!!! (4/27/2004 1:47 PM)
Without any rudder it will "walk" in the prop torque direction. It may stop cavitating with a rudder moving it in a straight line. I was worried about that very problem when you first described your project and the prop you were using. The prop pulls water from all 360 deg of it's rotation and it if it is too close to the surface it pulls in air as well. If you cant lower the prop enough, try fashoining a plate over the prop that will block the air from being pulled in from the surface known as a cavitation plate. All out board motors use them. You were very brave to put a boat in the water and try running it without a rudder. Your pond must be small enough to not worry about where it would end up when it took off. Oh, and for the record, I was in the Air Force but that was a long time ago. Please don't forget the camera next time!!!

Sandman2869 -> RE: 6' Home built Chain Saw Engine boat!!!! (4/27/2004 7:18 PM)
I just want to say you rock! I love your energy with this project! I can't wait to see pictures.

lmopar69 -> RE: 6' Home built Chain Saw Engine boat!!!! (4/28/2004 11:48 PM)
Ok, today I built a single rudder. Its friggin huge! Well, about 3 1/2" and sits as deep as the prop into the water. Probably too large and the servo will have a tough time moving it when its in the water, we'll see. I put it on the left side of the prop. Since I will try it first with a single instead of the dual that I plan on building, I should have probably put it on the right side of the prop. Especially since the thing already goes left on its own. Oh well. I made it out of a hinge, a chunk of alluminum, some screws, control rod through a brass tube and a standard servo. Maybe I will get the chance to try it out tomarrow, depends on if the wind here will slow down a bit. Been getting 40mph gusts today. Oh, and I ran it the first time on Milford Lake. The largest lake in Kansas. But since I knew I had no steering, I had an ace up my sleeve. I tied one of my kids kite strings to it and had the wife hold on to it, just to be sure.

skoda450 -> RE: 6' Home built Chain Saw Engine boat!!!! (4/29/2004 2:31 PM)
Until you solve the prop cavitation problem the standard servo will be fine. Even then it probably wil be OK. The rudder doesn't have to be that wide. You could also try moving the pivot point of the rudder to the rear some and leave some of the rudder in front as a leading edge force ballance. Dont go too far as this may cause a flutter at higher speeds. As for the wife with the string.... I get this mental picture of her being dragged across the lake by this monster boat and you yelling "LET GO OF THE STRING, HONEY!!!" Hum.. a reason to take the wife boating....

lmopar69 -> RE: 6' Home built Chain Saw Engine boat!!!! (4/29/2004 6:15 PM)
I wish i would have had enough power to pull her accross the lake! That would have been classic! Anyway, the rudder is on, and we took it out to test it. Worked pretty well, turns left great, going to the right is a little slow though. The prop is my big problem though. its just too big and the wrong style. It grabs too much air and had the wrong shaped blades for what I want. The boat is too slow, and the prop is dragging the motor down. So once I replace that, it should be even more fun... then maybe I will try the wife with kite string again.... can you say body ski'ing! lol Here are some pics of todays fun...

Daniel Ramsey -> RE: 6' Home built Chain Saw Engine boat!!!! (4/30/2004 4:50 AM)
Who says a person has to spend hundreds of dollars for an R/C boat? thats awesome! next thing you know your buddies back in Iraq will want you to build a R/C recon boat! Great work, I bet if you had enough engine you could really turn that prop but its definately too big. Didn't you have a small trolling prop? I'm guessing thats it, there must be some guys here that can give you a rough size/pitch dimension that would be better at the shaft speed. Good Luck! its such a carefree feeling being able to do WHAT you want and in whatever fashion, not many countries around can say that much. Especially the people of Iraq.

lmopar69 -> RE: 6' Home built Chain Saw Engine boat!!!! (4/30/2004 4:47 PM)
I agree with that D.R. Livin here sure as heck beats living over in Iraq. Well, I have now come accross a new problem. Maybe someone can help with this one. The largest RIGHT HAND prop I can find is a Octura 465. Not big enough. Since this thing turns clock-wise, it kinda leaves me screwed. So unless someone has a better idea, I guess its time to break out the sheet metal, tubing and mig welder and make me a prop. I figure after the 20 or 30th one I make I might get one that acctually works. Since I really have no clue what Im doing I will just look at a real one and try to copy it in the size I am guessing I will need. Im sure, like the rest of the boat, it will be no work of art, but if it does the trick, Im all over it. Plus, just like everything else, it sounds like fun. So, anyone else have any experience MAKING a prop?

OLD_SLOW and in the WAY -> RE: 6' Home built Chain Saw Engine boat!!!! (5/1/2004 3:12 AM)
what ya wanna do is....................... cut the diameter down on the prop you are runnin then try it if it needs more pitch then cup the ends of the blades Lots of good prop pictures and info

lmopar69 -> RE: 6' Home built Chain Saw Engine boat!!!! (5/1/2004 7:07 PM)
Well, this prop is some kind of cast iron type thing so I cant re-cup it without breaking it I dont think. I appreciate the link to that prop guy, I sent him an email to see if maybe he can give me some advice on it. Thanks.

skoda450 -> RE: 6' Home built Chain Saw Engine boat!!!! (5/3/2004 2:18 PM)
Great pics and they help us help you. You may have another problem with model boat props. The largest shaft diameter available is 1/4". It looks like yours is 3/8" or more? If you find a right hand prop in the size and rotation you are looking for, the shaft will be too large if my guess on the size is right. Call Octura and talk to them your problem. Their number is 847-674-7351. They were a big help to me when I was getting started. Just tell them you are looking for some technical support and you will get someone who will spend all the time with you you want. Maybe even more than you want. You can order a prop from them right then. Other wise your design of the drive system (forgive me) is flawed. Let me explain. The hull wants to plane. That is, to have water flow directly away from the hull bottom at the stern and the boat on top of the water vs. down in it. That leaves 75% of your prop out of the water and it is not designed to function that way. Even if you built a cavitation plate over the prop as I suggested earlier it won't help. The prop is still out of the water too much. Cutting the prop down won't help either, you still have 75% of the prop out of the water, you just have less prop! If you are sucessful in finding a right hand prop, try building a surface drive system that will support it. I have done this my self so it's not too difficult. Some aluminum angle, a 1/4" drive shaft, a 1/4" drive shaft bearing and support that hangs from the angle and coulpers for the engine drive shaft to the prop shaft. If you want I can try to post some pic of my drive system to help explain. You might try an Octura 1467 RH. It seems too small but you might be supprised at how well it will work. The "67" in the Octura part number indicates the diameter in milimeters. The largest diameter is I have seen is 82 mm so consider that in your next decision and after you talk with Octura. You might get away with just mounting it on the boat in the configuration you have it in currently. In any case it will be interesting. Good Luck

Page: [1] 2 next > >>

SITE MAP! : : FORUM RULES

© 2001 - 2007 24-7 RC, LLC, all rights reserved.

0.234375