ryan_t888

Also what is the reason for the extremely high canopy?

Ryan

ISIRC10

The canopy is for the GPS... It fits nicely in the bulge and still gets a strong signal.

yeah, I had to use it to get out of a couple of tight spots, as my launch spot was swamped by a fallen tree...
about the insiration, that is very true... I read your thread and a few others to help me out during the build.

guys, thanks for the great responses, the pics realy help. for the turn fin, I kinda want to be able to turn both ways, so can I add one to each sponson?

The feigao... I will see about it. any places that you guys recommend where they are cheap or are they all the same? I will probably run it off of the mamba max ESC after I waterproof it. maybe a hydra 120 in the future (a great present for the hollidays! )

ryan_t888

Offshoreelectrics.com or hobby city.com

As for two turn fins this will not work. They will fight each other and the boat will roll. Only make right hand turns.

What's the GPS reading as of your first few runs?

Ryan

sportygreg

My Feedback: (2)

Have you run it without GPS? Boat looks too heavy to me.[8D]

toyotatruckin

dont forget there is the left hand choice
Ill second the two turn fin thing,bad idea!

ISIRC10

ok, thanks, I have put one on the right sponson, might make it a bit longer though after the runs today. I am running 7-10 mph with the GPS, so my top speed without it is somewhere around 13ish... not blazing fast, but it is very rewarding. this time it wasn't the size of the lake, but the weeds and chop that messed up my runs. the weeds tangled in the prop, and in the vid, you can see that it takes the boat right off plane and creates the large amount of splashes (the tubes are hitting the water) however, I did manage some nice runs, and the turn fin seemed to help a bit with my turning. I am looking at the feigaos right now, and will probably make the purchase sooner or later (when my esc comes in from tower [:@] its been a three month wait so far)
I am still getting water into the hull, and I am guessing that its the hatch, as the front section ends up with all the water, no matter how well I tape the darn thing. I also had my first ding today, as I was making a straightaway run. the rudder caught a weed and I hit a rock that I had managed to evade that entire time. Ithink the damage can be fixed easily though... [8D]

[link=http://s215.photobucket.com/albums/cc21/ISIRC10/?action=view&current=haha.flv]video[/link]

I will get total weight tomorrow, its way past my bedtime! [sm=sleeping.gif]

ryan_t888

Even when its at full speed it still seems as if its ploughing a ton of water. More power will definitely help it out. What concerns me is your flex shaft has a tight bend where it goes from the strut to the hull too steeply. A brushless may over stress the flex in this area and cause breakage.

Other than that you are more than ready for some actual power!


Good Build
Ryan

toyotatruckin

also you might try using a flat cover instead of the cowling to drop a little weight, one thing i have learned over the years is the smaller the boat the more the little things will affect the outcome of the total performance and handling of the machine.

eboat

After you run is there anything getting hot ? motor esc or battery
Maybe while you are waiting for your brushless stuff and things are cool you could try the next size bigger prop

sportygreg

My Feedback: (2)

Stuffing tube is too long-flex needs less angle and teflon should fit into nose of strut to reduce friction.You also need a nylon washer or thrust bearing between prop and strut.Are you running X432 prop?Have you greased the flex shaft and prop shaft?How many turns motor are you using?If not 15 turn or lower,you may need a larger prop.[8D]

ISIRC10

as a matter of fact, the motor, battery and ESC are barely heating up at all, even with the water cooling not working and running three packs in a row. I will cut the stuffing tube a 1/4" shorter and extend the teflon tubing.

if I was to go for a bigger prop, what should I get, I don't know the turns of the motor, as it is from a hobbico wave rocket that someone threw out (and I salvaged )
it looks like something in the 24-30t range, and is prety torquey.

I still need to figure out what is wrong with my water pick up. it only works in the tub when I keep the drive submerged, and even then, it only exits as a trickle. could my problems be caused by the low speed of the boat? I checked the lines and tubing but there are no kinks.

what do you use to grease the flex shafts, I just use lithium grease, is that OK?

ryan_t888

Just a little clarification. There should be no bushing or bearing between the strut and drive dog. A thrust bearing should be placed at the motor where the flex hex meets the motor or mount.

The stuffing tube should cover the maximum amount of distance possible without causing any binding. I have knotted and destroyed many flex cables because the stuffing tube had not gone the longest distance possible. With my current setup, the stuffing tube stops 1/4" away from the flex coupler and fits over the strut.

With the cooling pick up I decribed previously there should be no issue with cooling. Post photos of how it had been changed.

Ryan

sportygreg

My Feedback: (2)

There is a difference of opinion on thrust bearing location-anything that keeps shaft from putting strain on motor under load will help.Depending on # of cells the wave rocket motor probably is not turning high enough RPMs.The size and weight of the Predator is similar to my Classic Roundnose Hydro and the designer calls for X432 prop and 11 turn motor for best performance.I run a 15 turn motor because I already had 15 turn ESC and it probably puts out way more RPM than the motor you are using.The Predator is heavier and rides lower in water than a plastic Wave Rocket so you need a higher performance motor.You probably don't even need the water cooling unless you have more than 7 cells or long run times-it just adds weight and drag to the boat.That's my opinion but there are people more knowledgable than me so I always defer to the experts when they point out how wrong I am

toyotatruckin

thrust washer at the drive dog/strut end of it is not needed just make sure you gap your shaft properly and there will be no problems, thrust bearing on the engine side-got me never gone down that road.

Actually (since i kinda new to electrics) could someone explane the use of a thrust bearing on the motor end, just curious here. thanks

ryan_t888

I like to place a thrust bearing between the flex hex (flex coupler) and motor mount. This takes the thrust loading off of the end cap of the motor.

Others like to place the bearing between the motor can and flex hex.

During my last race my thrust bearing blew up and the end cap on my motor had already been damaged from 1/2 a run.

When I get home from work I'll see if I can find a photo.

Ryan

sportygreg

My Feedback: (2)

Flyers use electric motors all the time without thrust bearings-after all,how can you use thrust bearing when prop is pulling shaft instead of pushing it?I'm sure a big prop pulling a plane creates as much thrust as a small prop pushing a boat.That being said,a bearing that relieves stress on a motor shaft is always a good idea but I have seen many RTR boats that do not even use bearings.The bushings or bearings in a motor will wear faster without a thrust bearing but the com and brushes will be shot by then anyway.I have a vintage Wildcat that never had thrust bearings and the original motors are still running strong.Brushed motors wear out but are not that expensive to replace.Now if you were running a high dollar brushless motor,a good thrust bearing would help protect your investment.Be that as it may,you still need a higher performance motor for your Predator to get it up out of the water.[8D]

ryan_t888

I fly many planes as well.

If you take a look at most motors the end cap in which a boat would press up against is not a solid part of the motor. The part in which a tractor style air prop will pull on is a solid part of the can hence no problems. I have had a few pusher style planes which eventually suffered from the end cap becoming loose. What I have learned to do is mount the prop hub nut as close as possible to the motor mount to stop it from coming apart. In turn I usually use a teflon bushing as well.

The end cap on most motors is usually press fit. The front of the motor is a solid part of the can itself. Not all motors are designed this way. Some can handle greater forces while others can not.

Brushed motors simply do not provide nearly as much power than a brushless motor so the effect is not as evident.

I know of several RTR boats that don't use a thrust bearing as well. The SV is a perfect example. A motor which can provide a decent amount of thrust and does not have a thrust bearing. If you read the super tune your supervee thread, there were a few cases over the years in which the motors and cap has started to become loose from the can.

Ryan

toyotatruckin

thanks for the info guys.
heres my predator its the one without hatch covers just finished up the sponsons second epoxy coat this evening..the other is a blizzard i just finished a couple weeks ago. just gotta figure out which one im gonna rig up?!>frustrating me lol

ryan_t888

Mike what setup are you going to run in either rigger? Oh and why not make your decision easier and rig them both up as different setups?

Ryan

toyotatruckin

hex.120 esc lehner XL5000 solinger hardware starting with a b/s/p 632 also have a b/s/p 1732 .130 flex no liner this was all going into the blizzard run on 6cell nimh but thinking 2s lipo

blizzard is 19 3/4 long and sponsons are 9" inside to inside, weight at 10.2 oz as it is now
predator is 21.5 long sponsons are 9 5/8 inside to inside, weight at 10.9 oz as it is now

personal opinion the predator will be more stable and handle a shade rougher water with close to the same speed

ryan_t888

Go for the longer hull.

With that setup you should see somewhere around 50mph.

Ryan

j.m.

I'm thinking about making one of these.

But i am wondering whether the rear sponsons are necessary or not?

Haven't seen them on any modern riggers. (rigged insanity, renegade rigger...)

How would an Orion 15X2 sv2 pro BB work?

sportygreg

My Feedback: (2)

You can run without rear sponsons but they help reduce drag-I run on 15 turn motor and it scoots along pretty good but won't equal brushless or be the fastest boat on the pond.My 700 powered Electro Vee is faster.[8D]

j.m.

how fast is it with the 15 turn?

ryan_t888

Many people prefer to not use rear ride pads for racing SAW. This is for pure all out speed as only the prop would touch the water in the rear.

I would say rear ride pads are helpful as they increase handling. I prefer to use them but they are definetely not needed for the smaller riggers.

Ryan