RE: STRETCHING A HULL...IS IT POSSIBLE ??? Old Graupner Systems Cat build
I and a couple club members had Systems boats back in the day (when they first came out) and they are weak to begin with. The ABS on some lots was thin and brittle, and after 25 years sitting in a box it has certainly not gotten any thicker or stronger. One nice thing about the Systems is that it handled pretty well - the long narrow "scale" cats do not handle nearly as well. Particularly if you use steerable outdrives (I ripped it off my Systems and never regretted it) the lengthened cat will hook and roll over in a heartbeat. You will not be happy with the result after all the effort and $$ spent. IME you would be far better off selling the boat as is and either building one from scratch, or buying a more suitable hull to build. There are a lot of good, new, strong fiberglass cat hulls available for not much more than you can get when you sell the Systems. Then you will have a stronger, better looking and better performing boat which you can be proud of. Or you can cobble together a boat almost guaranteed to disappoint. On the other hand I can understand the attraction to doing it all yourself, and if you decide to go that route I wish you good luck and lots of fun. [color=#66FFFF].[/color]
Posted on: 9/15/2012 8:57 AM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11229286

RE: new guy wants boat
[b]- Item #868397 in the clazsifieds is a genesis boat for sale for $400 seller says it was ran once on ''8s'' & runs like 60 mph but comes with 4 3s[/b] [color=#330099]Don't believe everything you read on the Internet.[/color] [b]- I dont know all the RC lingo [/b] [color=#330099]You can learn a lot here: http://www.rcuniverse.com/forum/m_9069147/tm.htm[/color] [b]- Does RTR mean jt comes with a controller as well ? Does it come with a charger for the batteries ?[/b] [color=#330099]RTR = Ready To Run, usually includes motor, speed controller, radio, all hardware. Usually does not include battery, charger, balancer.[/color] [b]- Is it normal for someome to try the boat out once then sell it?[/b] [color=#330099]Yes, some folks are disappointed with the performance, some don't use it enough to justify having it, some break it and try to unload it on some unsuspecting newbie.[/color] [b]- How expensive are the ''8s'' ?[/b] [color=#330099] Twice as much as 4S. Sorry, it depends. That is usually two 4S packs wired in series, or it can be four 2S packs. Cheap packs from China, mid-quality packs or high-quality packs, you pay your money and take you chances. [/color] [color=#33FFFF].[/color]
Posted on: 9/10/2012 7:06 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11224449

RE: System too hot! Whats wrong???
At least [i]part[/i] of the problem is the packs. Cheap packs may be fine for RTR boats, but for high amp draw applications they often just don't cut it. Some burst into flame, but the more insidious problem is that they cannot supply the amps the motor needs, which starves the ESC and overheats it badly. Low-performance packs are one of the main causes of ESC failure. Castle has stated this many times, and recommendations 2P setups to help alleviate the problem of cheap packs: http://www.castlecreations.com/support/documents/neumotors-castle_boat_apps.pdf Other issues could be long power wires - also death to ESCs. High resistance connectors are bad too. Too high or too low motor timing can heat the ESC up as well. Add everything up and it's no surprise so many ESCs bite the dust. I posted this elsewhere, but it is an recent example (last Saturday) of a pack which did not perform. It should have been good for 200 amps, but it burst into flames in a setup pulling no more than 150 or so. [IMG]http://i50.tinypic.com/f2kozl.jpg[/IMG] The motor is also too small for that large impeller. A surface drive prop suitable for that motor would be 45-48 mm, a 53 mm impeller creates a lot of resistance. I am surprised it is not hot as well - another reason to suspect the packs.
Posted on: 8/6/2012 7:36 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11183628

RE: Why is this happening to my Geico ?
If the cable was wound backwards it would probably have self-destructed by now. The reason for pushing all the greas and water up the tube is in front of the drive dog - get rid of the large "thrust washer" in front of the drive dog. That is absolutely pushing [b]a lot[/b] of water up the cable. It is not needed, just leave one cable diameter of gap between the dog and the strut. Next, Try slipping a short piece of silicon fuel tubing over the inboard end of the stuffing tube, leave just enough hanging off the end to just barely touch the cable - see photo. That should keep most all the water from coming up the stuffing tube. [IMG]http://i46.tinypic.com/az8apt.jpg[/IMG]
Posted on: 8/5/2012 7:15 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11182312

RE: Boat cuts out at just over half throttle
Was the 15 volt reading taken after a run or before? If before the run then your problem is the packs are not fully charged. If after, then it may be a boat/ESC issue. The motor is almost certainly a 4-pole design, so use the [b]2-4 pole inrunner[/b] at programming for timing. Set to [b]hard cutoff[/b], this will tell you is the problem is the ESC/settings. 12 volt cutoff is fine as is auto throttle. OTOH poor quality packs will do what you are seeing, high output at first then drop off substantially until hitting the LVC. I have seen some video of the boat and it looks pretty decent. How fast does it go for the first minute, is it close to the speeds in the video? [color=#66FFFF].[/color]
Posted on: 8/5/2012 6:59 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11182290

RE: Aquacraft Revolt 30
[quote]that LiPo should sustain a 200 amp draw - did it drop below 80% DOD?  Or was the setup drawing more then 200 amps continuos?[/quote] You can miss the point when you struggle to make excuses for the burn-down.....cheap LiPos simply cannot be trusted. Was the label a lie, or was the maker's QC terrible? The pack shown was one of two in the boat, running in series. Both were fully charged. The other pack had 50% remaining and was 120*F. You be the judge... You buy a cheap pack and then you don't have your money and you may not have the pack - or if you are unlucky enough then you don't have your boat either. Doesn't happen every time of course, but the risk is there if you use them in high amp draw boats. Limited motors and 70-80 amps should be no problem. This is just a warning for those who wonder about LiPo safety. What you do with the information is up to you. [color=#00FFFF]. [/color]
Posted on: 8/5/2012 6:36 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11182263

RE: Aquacraft Revolt 30
A club member has had a Revolt for a couple months, and the more I see it run the more impressed I am with the boat. All he has done is change to an m445 prop with some strut adjustments and he's getting consistent 44 mph runs. It handles great with excellent speed and reliability. As for LiPos, be aware that low end packs may work fine in low amp draw applications like the Revolt (70-80 amps average) but beware of running them in high power setups. The pack below worked fine in the Revolt, but running them for less than two minutes in a P Sport Hydro setup gave this result - fire, smoke and drama. [IMG]http://i45.tinypic.com/ou9rah.jpg[/IMG]
Posted on: 8/5/2012 2:24 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11181926

RE: What really grinds my gears.
zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz...oh wait, I woke up. Coming here with an attitude isn't going to get you much help - it may be difficult to understand but that kind of thing offends a lot of folks. BTW this particular forum is quite OLD - 2003. RC Universe began prior to 2002. Yes, the formula is really that simple - [b]mAh x "C" = maximum continuous amp draw[/b] [b]BUT[/b] there are always buts. If you want your packs to last then don't exceed 80% of that maximum. So for a 40C/5000 mAh pack that's a maximum of 160 amps. [b]BUT[/b] with cheap packs the stated mAh and "C" ratings are probably inflated, so the formula doesn't work. One of the things you pay for with higher end packs is real performance numbers, or at least numbers closer to the truth. We went through all this with round cells a decade ago - cheap packs with fantasy performance numbers. Virtually all LiPos come from Asia, [b]but[/b] not all come from the same factory. And even cells from the same factory are not all the same. In any production lot there is a variety of performance values, some cells are very very good, some are very poor. The factory does not throw anything out, they sell the lousy cells to the sellers who sell cheap packs and the high performance cells to the sellers to provide premium packs. All very normal and natural, this is one reason the cheap packs are cheap - they may be sh*t but some consumers don't care, all they want is the low price. Unfortunately they often end up without their money [u]and[/u] without cells which work...not much value there. If all the cells a "power seller" sells are sh*t it will do you no good to get returns...... [color=#33FFFF].[/color]
Posted on: 8/3/2012 8:44 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11180327

RE: New tunnel hull concept
How long have you been working for Fast RC Boat? [;)] How do you define" long run times"? With what batteries? What is "good performance"? Where is it made? How much does it coat? There are a number of good RTRs currently on the market with both 'good performance' and relatively long run times. I hope that the Fast RC Boat OPC entry is an excellent addition to the list.
Posted on: 7/27/2012 7:55 AM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11171174

RE: tunnel hull turning
[quote]sorry it is a 155 oz servo[/quote] Torque is not the only important spec for a OPC servo. Centering power is [b]very important[/b], and only digital servos will give you that. Some analog servos will work okay, but I have gone to all digital for my boats (inboard and OB) and no centering problems, you feel really connected to the boat. Flexing in the pushrod can also cause this. Push/pull is probably best, if not use a heavy, short rod; coveing it with a tight-ritting carbon fiber tube will eliminate flex. [color=#33FFFF].[/color]
Posted on: 7/20/2012 12:24 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11162679

RE: My first boat pics
It is difficult to tell from the photo but it [i]looks[/i] like there is another hole in the carb arm...move the clevis to that hole. If you can do that it will give you plenty of movement. [color=#66FFFF] .[/color]
Posted on: 7/9/2012 7:22 PM by Author "Got RPM" in the forum "RC Airboats"
http://www.rcuniverse.com/forum/fb.asp?m=11149427

RE: Nubie, have lipo question
I'm afraid you don't know what you are talking about. The mAh is the same for each cell in a pack - a 3000 mAh 3S pack has three 3000 mAh cells in it, [b]not[/b] three 1000 mAh cells. [8|] You also ignore the "C" rating which is so critical for high amp draw applications - they are often bogus on budget packs but are accurate on premium packs. You actually do get what you pay for - if you need it. You can rationalize your affinity for cheap packs all you want, thank goodness you're not a Glaswegian! As I said above, I recommend that boaters spend their money wisely. [color=#00FFFF].[/color]
Posted on: 7/8/2012 6:39 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11148053

RE: Nubie, have lipo question
You definitely get what you pay for with batteries, it is [i]absolutely not[/i] just a different sticker. LiPos are no different than the nickel cell we used for many years - a limited number of cell manufacturers, but a [b]WIDE[/b] range of quality from the sellers. The manufacturer rates all his cells and puts them in performance groups. The best performing cells are sold at a premium to pack builders who specialize in high-quality products - and they expect to be paid for the premium. Mid-level cells go to the mid-priced pack builders, and the low end are sold cheap to the "budget" pack builders. You will not get the same quality from the budget cells as you will from the premium packs, period. But you may not want or need the premium packs. Boats with amp draws like the Revolt and other RTRs can get by fine with less costly packs. Just don't be surprised if you order a budget pack and find that one or more cells won't match or are puffed - that is the risk of budget packs. Also, the "C" rating of budget packs is suspect. I have seen too many budget packs get blazing hot in setups which are mild for premium packs - that means the labeled "C" rating was developed with a printer, not by actual testing. The budget pack builders know that the consumer can't actually test the pack for the rating, so they feel safe inflating it to fool the consumer and increase sales. HK is notorious for this, as were a lot of pack builders for nickel cells back in the day. Same scam, different decade. You certainly don't have to do what I do, but I'll tell you. Because I race most of my boats, I buy premium packs from Hyperion or ThunderPower. Performance is record-setting, the packs almost never need balancing, and they last for multiple seasons of hard racing. If I damage a cell or want a new pack, I can return the used packs for ~40% credit on brand new packs even when out of warranty. Try that with a HobbyKing pack. Remember, [u]all of the power in an FE boat is in the cells[/u]. If all you are doing is bashing around then the budget packs are fine if you understand the risks. If you are racing, then the guy with the best packs has the best chance of winning given equally setup boats. It's you money, spend it wisely. [color=#66FFFF].[/color]
Posted on: 7/8/2012 11:45 AM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11147636

RE: New boogie board air boat problems
A 12" prop is pretty large for the average 480 motor, what is the motor Kv? What is the prop pitch? [color=#66FFFF].[/color]
Posted on: 7/5/2012 7:52 PM by Author "Got RPM" in the forum "RC Airboats"
http://www.rcuniverse.com/forum/fb.asp?m=11144725

RE: Brushless upgrade...
[quote]...was thinking of a 3 to 4 foot cat maybe longer just wondering what size motor and esc ill need to get it up to 50 to 60[/quote] I can give a few examples, a lot depends on how you want to run the boat - sport running, oval racing, SAW racing, run time expected, etc. The run times I show below are for full throttle racing, less severe running would extend those times. [b][u]34" Aeromarine Sprint Cat:[/u][/b] Neu 1527/1250 Kv motor, Castle ICE240 controller, 6S2P/10,000 mAh, x455 prop race setup 55-60 mph running for 2-3 minutes, could run longer if slower Scorpion 4025/1100 motor, Castle ICE240 ESC, 6S1P/5000 mAh, x455 prop sport setup 45-50 mph running for 2-3 minutes, could double that if running 2P [b][u]41" Stryker catamaran:[/u][/b] Lehner 3060/10 motor, Schulze 40-160 controller, 10S1P/6600 mAh, x465 prop race setup 60-65 mph, 2-3 minutes racing, more with 2P Scorpion 4035/850 motor, Schulze controller, 10S1P/6600 mAh, x457 prop sport setup 50 mph for 2-3 minutes, longer with 2P These are boats I run so I know they work, no "theory". You can spend more or less, but remember you can have speed, reliability or low cost - [u]choose any two[/u]. [color=#00FFFF].[/color]
Posted on: 7/5/2012 7:48 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11144722

RE: 320a brushed esc
That ESC is a joke. A low volt (7.4 volts) low amp (15A sounds about right) controller. Either the 320 amps is a typo or that is the amperage it takes to make it blow the hatch off the boat. What can you expect for $11 when REAL 300 amp controllers cost hundreds? [color=#33FFFF].[/color]
Posted on: 6/29/2012 3:15 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11137005

RE: Probat mystic 29
Like Dan says, set it up like the instructions say and it will work. Put the boat on a flat tabletop to insure that the strut is in the correct position. One thought - how many and what kind of cells are you running? [color=#00FFFF].[/color]
Posted on: 6/4/2012 7:07 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11106643

RE: V-hull with 2 motors
[quote]The hull I'm thinking to use is the HK Osprey which is 42 inches long. Do you guys think one motor would be able to push that hull?[/quote] I like that this hull [i]"glides and planes very well"[/i]. A single motor will work fine - if like Harry says it is enough motor. We had several guys in the club with 39" DF hulls (same size as the Osprey) which ran great with Neu 1527/1Y motors on 6S. Speeds were mid/high-50s on around 3500 watts in these lightweight hulls. [color=#33FFFF].[/color]
Posted on: 6/1/2012 7:15 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11103215

RE: V-hull with 2 motors
It has been done successfully, a club member built one on a dare and it worked fine. Others have done it as well, the shallower the vee the better. I don't see the advantage today with all the large format single motors available - only one motor/ESC combo to go bad - but if you have a hankerin'.... [IMG]http://i45.tinypic.com/351hm9v.jpg[/IMG]
Posted on: 5/30/2012 7:03 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11100635

RE: Whats the best motor?
Tell me that's a typo on the prop, an x467/3 would cook your setup - if Octura made it. That's too big for a Neu 2215..... [color=#00FFFF].[/color]
Posted on: 5/28/2012 7:44 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11098013

RE: Motley Crew Info ?
Using 3400 mAh (80%) out of 4200 mAh at an average 60 amp draw (realistic for the stock setup) means 3.4 minutes of run time. At this draw rate an extra 800 mAh (5000 mAh) extends your run time by ~35 seconds. One reason that some folks get longer run times is because their cheaper packs do not put out the power of higher end packs. It is tough for most folks to time their runs so that they do not hit the LVC. Constantly hitting the LVC pack after pack can cause a reduction in pack life, made worse by high pack temperature. At lower amp draws the packs should not get too hot, but at higher amp draws high temperatures/damage is probable. If your packs are under 130*F when they come back in you are probably fine.
Posted on: 5/25/2012 8:09 AM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11094215

RE: 41
Harry has a point, a big 10S cat can be expensive. You need to know what you are getting into before you start. Harry and I both have run plenty of big 10S boats and we have a pretty good idea what works and what does not. I'm not trying to discourage you, we'll give you plenty of good advice. But plan on [u]well over[/u] $1000 for the build. With FE boats, you can have cheap, fast or reliable, choose any two. BTW, don't listen to advice from those who have not actually built and run 10S boats. It is always so much easier to plan someone else's build when it isn't your money being spent. [color=#00FFFF].[/color]
Posted on: 5/24/2012 5:39 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11093685

RE: New to RC boats 48
You are building a very uncommon boat with an uncommon setup. Apparently no one here has experiece with a large submerged drive boat. Afterall, this is a fast electric forum, and your boat is a scale boat. I'd suggest looking in the scale forums to find folks with experience building similar models. All the large boats I've built are 41"-45" long, run surface drives and go 60+ mph - a far cry from what you are after. If it were me I'd run two 4025/500 outrunners on 6S each with 150 amp controllers and low pitch 45-50mm props; speeds around 25 mph. But that's just a guess. [color=#33FFFF].[/color]
Posted on: 5/12/2012 6:56 AM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11077921

RE: motors for1/8 miss budweiser?
One certainly does not need to add 8 lbs of electronics to the boat to make it run! That's probably a bad idea for some less-than-full-bodied hulls anyway. Plenty of FE 1/8s have been set up with the Neu 1527/1.5Y motor on 10S1P. 1527/1.5Y - 21.8 oz [u]10S/6500 mAh - 62 oz[/u] Total - 5.25 lbs The above is a cheaper setup than the 8# one too, and is proven to win races. Actually it is too fast, easily outrunning nitro 1/8s. For even less cost/weight: Scorpion 4035/800 - 15.3 oz [u]8S1P/5000 mAh - 37.5 oz[/u] Total - 3.3 lbs This setup will give closer to 1/8 nitro performance for a lot less $$ and weight than the 8# fiasco. Upping packs to 6500 mAh gives lots of run time....relatively speaking anyway. [color=#33FFFF]. [/color]
Posted on: 5/2/2012 8:07 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11066238

RE: 60 mph boat
or on and off, etc.). I built a FC Shocker (37") for SAW racing and got it over 90 mph before... boat. Here are a couple photos of my 90 mph 6S RiverCat, I never got a pic of the Shocker. [:o] [IMG
Posted on: 4/28/2012 6:32 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11060633

RE: surface radio for boats
[quote]Now all this mixing and servo reversing aren't needed...[/quote] Perhaps for [i]YOU[/i] advanced features aren't needed, but the OP says he wants to upgrade. The Tactic is a decent entry-level radio, but I outgrew that kind of setup twenty years ago. In reality dual rates, exponential, end-point adjustment and model memory are [u]very[/u] handy and when used correctly can make a poor-handling boat run far better. I wouldn't have a radio without these features. Especially if you race or have a fast boat or multiple boats, a better radio is warranted. I run a Futaba 4PK, but most of the members in my club run Spektrum marine radios and love them. Easy to program, lots of model memory, not too expensive, reliable.....what else do you need? [color=#00FFFF].[/color]
Posted on: 4/15/2012 7:30 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11043517

RE: I have some Electric Swamp Buggy Questions.
1.That is a very small, low-powered setup, so make the boat small. No longer than 18". 2" wider than the prop, minimum. 2. Put the motor in the back like you see on most airboats. This helps to keep water out of the prop when running. 3. I built a lot of FE boats out of 2" Styrofoam. Cover it with 1/2 to 1 oz cloth, use thinned epoxy to keep from melting the foam. Thin the epoxy with about 25% isopropyl alcohol. [IMG]http://i43.tinypic.com/35jfgnm.jpg[/IMG]
Posted on: 4/8/2012 6:25 AM by Author "Got RPM" in the forum "RC Airboats"
http://www.rcuniverse.com/forum/fb.asp?m=11032858

RE: genesis cat help
I assume this is the big "Genesis" cat from HobbyKing, hull only? If so, 2S will not work well at all - not nearly enough power for this 40" hull so run time will be short. Even the 3S setup they have in the RTR is marginal if any kind of performance is wanted. We normally run 6S or more in hulls that size....unless there is another "Genesis" cat out there that is smaller. "Low price" and "good motor" is really an oxymoron. How much are you willing to spend? How fast do you want to go? How long do you want to run? [color=#00FFFF].[/color]
Posted on: 4/4/2012 7:27 PM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11028715

RE: amps.... really how much
[quote]ok by the looks these things draw carzy amounts of amps compared to cars/buggies/truggies...[/quote]Uh, yes. If you let off the throttle of a car it coasts for quite a ways. A boat immediately drops off plane and stops quickly. Water has a lot more drag than air and wheel bearings. The biggest problem car guys have when they transition into boat is pulling too many amps. They just don't understand the difference. My P Mono racer logs 190 amps continuous, with peaks of near 275 amps. Run it for more than 6-7 laps and it will burn down. [color=#00FFFF].[/color]
Posted on: 4/4/2012 4:05 AM by Author "Got RPM" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11027701

RE: New build 3pt wlc-isetta
I really like the clear prop guard, and the safety needle valve adjuster. Oh, and the BMW too. Good work! [color=#00FFFF].[/color]
Posted on: 4/2/2012 5:51 PM by Author "Got RPM" in the forum "RC Airboats"
http://www.rcuniverse.com/forum/fb.asp?m=11025793