Something a bit different! Model Power Boating. RC Catamaran build thread.
- Thread starter Phate
- Start date
OK so I have plenty to share on here including the final build log update but I know you're more excited to know how today went...
I have 2 statements from today
- It is fast...very...VERY fast
- It crashed!
Let me run through how it happened as I remember it and what transpired afterwards.
So we're at the lake. Todays objective is for the Orion to go around it and get it running as new engines and boats are often a bit of a nightmare to get running properly. Anyway, we're at the lake as you see above and Dad begins to set the boat up, he configures fuel mixture to run it very rich to ensure we do not start blowing glow plugs and to keep plenty of fuel in the engine. He checks it over, tries to start it, it fires instantly, throttle response is good, nothing else for it. He throws it in the water, I am with the controller.
It hits the water and instantly leaps out, I can't quite describe it. He throws it forward the engine has so much torque it goes from standstill to maybe 20ish mph in the space of about 2ft and actually jumped out of the water doing so and it began to skate forward quickly. Throttle is set to 50% and it is already going as fast as my other boat at full speed (confirmed 45mph)
Instantly check steering, we're good. Not as response and sharp as I would like and am used to with my smaller cat but I put this down to the sheer size of the thing. So start making laps around the lake, checking temp from the onboard sensor, its good. Here is where the problem started.
From my position the boat is at 12 o clock I try increasing the throttle marginally but its not making any difference, the engine is running too rich, understandable. Start to turn right as the boat is now at 2 o clock, and suddenly...explosion of noise, the engine has picked up and come on the exhaust pipe, and now is blasting along and I mean really really going, easily 50+ mph. I reduce throttle, no response ****! The speed is still increasing and I've lost steering, double ****!
Picture it, the boat is now travelling at roughly 55mph in a straight line towards the far right corner of the lake!
BANG
Boat hits the brush, engine is screaming. Try cutting throttle from the radio, nothing. Drop the controller and began sprinting down the lake towards it. All I am hoping is that the engine keeps going, if it stops suddenly then it's blown a conrod or similar and we're done for.
I made it to the boat and stuck my thumb over the carb to suffocate it and stop the engine.
The boat is looking a state at this point
- the front of the boat has split open horizontally and one of the fuel tanks is on the ground infront of it, the other hanging out of the front, still attached. So the force of the impact has dislodged the tanks and with them being 500ml each and pretty much full the boat came to a sudden stop and they kept going and forced the front of the boat in two
Anyway, picked up the pieces and brought the boat back to the dock and began checking the engine. Compression is perfect, engine seems totally unharmed! Thank god for that
- that was my biggest worry, the rest is nothing in comparison, if it had gone it would have been 850eur to replace it.
We put the boat in the car and continued the day at the lake (we took 4 boats overall) and decided to look later.
Fast forward a bit after a brilliant day at the lake. We got it home and investigated.
Here is what we think happened, and of which, its all totally my fault (live and learn!)
- The linkage between the throttle servo and carb was completely disconnected, like someone had pulled it apart. So this wasn't secure enough, also the carb on these are spring loaded to spring open to fully open. This explains the sudden explosion of power and accleration
- The rudder has 2 bolts in it, a thick metal one to hold it on and a small soft brass one to keep it facing downward. The idea of this is if the rudder were to hit a solid object the brass bolt would snap and it would avoid ripping it from the transom. When I was building it I accidentally sheered the brass bolt myself and FORGOT TO REPLACE IT - doh! It is entirely possible that as the boat sped up, the sheer force of the speed & water just pushed it upright. This explains the lack of steering
So yeah, lessons learned. Here is the front of the boat where all the damage is.
After getting it home, I removed all the hardware and cleaned it, the entire boat and all components were just completely covered in fuel thanks to the tanks and their little vacation they took. Afterwards Dad took a look at the damage. He gave it a thumbs up and said its an easy repair, he'll also reinforce the front of the boat in case we have any future mishaps
The sad note...I fly back to the Portugal tomorrow, so this thread will be a little quieter until January, which is when there will be more test runs. Also, there was no video footage, everyone was just a bit stunned at how it was moving and forgot to pull out a phone. The plan is for Dad to repair the hull in my absence and I'll reassemble the boat when I come back.
We are also discussing entering next years tournament. The boat shocked us all with its speed and agility enough to make us consider it. If that happens I'll keep this thread running with our antics from that
I have 2 statements from today
- It is fast...very...VERY fast
- It crashed!
Let me run through how it happened as I remember it and what transpired afterwards.
So we're at the lake. Todays objective is for the Orion to go around it and get it running as new engines and boats are often a bit of a nightmare to get running properly. Anyway, we're at the lake as you see above and Dad begins to set the boat up, he configures fuel mixture to run it very rich to ensure we do not start blowing glow plugs and to keep plenty of fuel in the engine. He checks it over, tries to start it, it fires instantly, throttle response is good, nothing else for it. He throws it in the water, I am with the controller.
It hits the water and instantly leaps out, I can't quite describe it. He throws it forward the engine has so much torque it goes from standstill to maybe 20ish mph in the space of about 2ft and actually jumped out of the water doing so and it began to skate forward quickly. Throttle is set to 50% and it is already going as fast as my other boat at full speed (confirmed 45mph)
Instantly check steering, we're good. Not as response and sharp as I would like and am used to with my smaller cat but I put this down to the sheer size of the thing. So start making laps around the lake, checking temp from the onboard sensor, its good. Here is where the problem started.
From my position the boat is at 12 o clock I try increasing the throttle marginally but its not making any difference, the engine is running too rich, understandable. Start to turn right as the boat is now at 2 o clock, and suddenly...explosion of noise, the engine has picked up and come on the exhaust pipe, and now is blasting along and I mean really really going, easily 50+ mph. I reduce throttle, no response ****! The speed is still increasing and I've lost steering, double ****!
Picture it, the boat is now travelling at roughly 55mph in a straight line towards the far right corner of the lake!
BANG
Boat hits the brush, engine is screaming. Try cutting throttle from the radio, nothing. Drop the controller and began sprinting down the lake towards it. All I am hoping is that the engine keeps going, if it stops suddenly then it's blown a conrod or similar and we're done for.
I made it to the boat and stuck my thumb over the carb to suffocate it and stop the engine.
The boat is looking a state at this point
- the front of the boat has split open horizontally and one of the fuel tanks is on the ground infront of it, the other hanging out of the front, still attached. So the force of the impact has dislodged the tanks and with them being 500ml each and pretty much full the boat came to a sudden stop and they kept going and forced the front of the boat in two Anyway, picked up the pieces and brought the boat back to the dock and began checking the engine. Compression is perfect, engine seems totally unharmed! Thank god for that
- that was my biggest worry, the rest is nothing in comparison, if it had gone it would have been 850eur to replace it.We put the boat in the car and continued the day at the lake (we took 4 boats overall) and decided to look later.
Fast forward a bit after a brilliant day at the lake. We got it home and investigated.
Here is what we think happened, and of which, its all totally my fault
(live and learn!) - The linkage between the throttle servo and carb was completely disconnected, like someone had pulled it apart. So this wasn't secure enough, also the carb on these are spring loaded to spring open to fully open. This explains the sudden explosion of power and accleration
- The rudder has 2 bolts in it, a thick metal one to hold it on and a small soft brass one to keep it facing downward. The idea of this is if the rudder were to hit a solid object the brass bolt would snap and it would avoid ripping it from the transom. When I was building it I accidentally sheered the brass bolt myself and FORGOT TO REPLACE IT
- doh! It is entirely possible that as the boat sped up, the sheer force of the speed & water just pushed it upright. This explains the lack of steeringSo yeah, lessons learned. Here is the front of the boat where all the damage is.
After getting it home, I removed all the hardware and cleaned it, the entire boat and all components were just completely covered in fuel thanks to the tanks and their little vacation they took. Afterwards Dad took a look at the damage. He gave it a thumbs up and said its an easy repair, he'll also reinforce the front of the boat in case we have any future mishaps
The sad note...I fly back to the Portugal tomorrow, so this thread will be a little quieter until January, which is when there will be more test runs. Also, there was no video footage, everyone was just a bit stunned at how it was moving and forgot to pull out a phone. The plan is for Dad to repair the hull in my absence and I'll reassemble the boat when I come back.
We are also discussing entering next years tournament. The boat shocked us all with its speed and agility enough to make us consider it. If that happens I'll keep this thread running with our antics from that
I said this to Dad afterwards in the shed!Well, at least the engine should be run in.
Shame you're away until January. Thanks for the updates, I look forward to more when you're back.
"Well thats probably run the engine in by now" - he laughed and commented saying on his one (he is going to order the same engine) he is just going to do the same as part of the run in process.
I might have some more info to share tomorrow, right now the boat is indoors drying out and tomorrow the repairs *should* begin before I fly back
Ah man, that's bad luck. One of my boats I could never get the electronics sealed (pressure tests and submerged in a bucket over night all good, but in use not good) so after 10 odd minutes of racing, would go out of control and up the bank. Always messy.
The thing is, if the engine had cooked, I would have been very annoyed at myself, but its fine. So I sit here now and laugh & smile about it. Understood where I went wrong, so we will repair...then have another go
With this hobby you have to take it with the not "if" you lose control but very much "when" you do. It IS going to happen at some point.
With this hobby you have to take it with the not "if" you lose control but very much "when" you do. It IS going to happen at some point.
Soldato
You can get that exact issue from a loss of signal. If the connection goes they can just loose control at full throttle. Have you checked your batteries?
What was the radio box made out of?
We have 2 other boats which have radio boxes made from fiberglass with perspex lids and they have been awful. Consistently damp/wet inside even with breather holes made and its just rotting the components inside. Tonight we actually made the decision to change these out for something else. Too unreliable.
it wasn't signal loss, well I don't think so anyway. When I got to the boat the throttle servo was in the right position, but the linkage wasn't connected. So it had become physically disconnected. I still had a full connection to the boat.
Also, I do have failsafes programmed in, so if it loses a signal connection and doesn't regain it it will/should shut the boat down.
Fibreglassed in ply bulk head at the rear of the boat. Full fibreglass boat.
About 15mm wide x 5mm deep black foam tape and a bolted down perspex lid, which was about 5mm.
Never in any test did a drop get through though, so annoying lol.
About 15mm wide x 5mm deep black foam tape and a bolted down perspex lid, which was about 5mm.
Never in any test did a drop get through though, so annoying lol.
Sounds like condensation build up to me. Bloody frustrating though!
I said this to Dad afterwards in the shed!
"Well thats probably run the engine in by now" - he laughed and commented saying on his one (he is going to order the same engine) he is just going to do the same as part of the run in process.
I might have some more info to share tomorrow, right now the boat is indoors drying out and tomorrow the repairs *should* begin before I fly back
Haha, nice one. A bit of damage never does any harm. I think they look better once they're "worn in" a bit anyway.
"Battle damage"
My first comment when I brought it back to the jetti to the small crowd of regulars was "...well I am glad I didn't paint it first"
Soldato
Ffs we were only joking when we said we're only following to see when it crashes and sinks!
To be fair, it all adds to the log/story... You'll look back and there will be much chortling. Bad luck!
To be fair, it all adds to the log/story... You'll look back and there will be much chortling. Bad luck!
Already chortling buddy
- as said. It's just part of the fun and the hobby! If you can't handle the bit when it crashes then this hobby isn't for you!"Battle damage"
My first comment when I brought it back to the jetti to the small crowd of regulars was "...well I am glad I didn't paint it first"
"You were only meant to row the bliddy oars off."
(Coat, no several coats, already got.
)
Take the whole blimmin rack!"You were only meant to row the bliddy oars off."
(Coat, no several coats, already got.
Caporegime
Excellent! thread delivered 
Its nowhere near as bad as my housemate at uni that bought an RC helicopter. Maiden flight was less than 10 seconds and needed repairs that cost half of the purchase price. He got better with it though!
Its nowhere near as bad as my housemate at uni that bought an RC helicopter. Maiden flight was less than 10 seconds and needed repairs that cost half of the purchase price. He got better with it though!