BJ29 Pilots, what is your setup to avoid the bouncing?

[CHIEFY_44]

I didn't add weight at all, and yes I mean the 2 part foam from ose, and I mean fill sponsons with it so that the foam finishes 2inches from the hatch opening or so you can get at the water outlet if you move that, basically I covered the Styrofoam that is in there already. I have also tucked the rudder blade towards the hull doing this seems to pull the front down, you could try that.

[scrillamil]

I was wondering same thing😉 Chiefy boat runs great that's exactly what I'm hoping for just want to reduce the hopping on mine.

[dre414]

Thanks again Chiefy. I looked around, i guess 2part polyurethane closed cell light density is what I should be looking for. Looks like scary stuff to work with but what's the worst that can happen right? I think I'll move the battery trays, try the rudder and mess with weight distribution a little more before I play with the foamy stuff.

I'll keep you all posted.

[lenny]

Good to see it is running smooth for you now.
So how did you go about getting the rudder to tuck in ?
And also what size cells are you running in the video ?


I think when you added the foam to the sponsons that also added some dead weight to the bow.

I didn't add weight at all, and yes I mean the 2 part foam from ose, and I mean fill sponsons with it so that the foam finishes 2inches from the hatch opening or so you can get at the water outlet if you move that, basically I covered the Styrofoam that is in there already. I have also tucked the rudder blade towards the hull doing this seems to pull the front down, you could try that.

[CHIEFY_44]

This is the setup in that video.
T-180
Leo 4074
M445 prop
4s2p 4000 maho
Strut level with sponsons and no angle
Rudder tuck in towards rear of hull.
Ok Lenny how I tucked the rudder was I replace the bottom bolt in the blade with a smaller one, actually its a plastic/nylon shear bolt now and when I did this it allowed the blabe to be tucked in towards the hull, why doing this helps I don't know why, but it does.

[lenny]

Hey,

Thanks for the info on the rudder.

The rudder most be a better setup than the Mystic rudder now,

With the new brake away bolt.

Could someone post some good pictures of the transom and all the hardware please,

I did a search for pictures, But nothing any good showed up.

[AlanD]

Olwarbirds, how did you add on to the battery trays? It sounds like you have the same Thunder Power 5000mah/65C/3S packs I'm using. My new BJ29 is 100% stock but my first run showed some minor signs of bouncing when I gave about 80% throttle. I'm curious what your mods look like. If you can share some photos, that'd be great.

For what its worth my sponsons are 100% flat and dont need any blueprinting. With Dre's pointers, I placed the battery packs 50% hanging over the front edge of the tray with the leading edges of the batteries on the hull center.

[olwarbirds]

Alan, I just bought a new digicam today :) ... we will be posting pics and more vids very soon... We are no longer running the stock setup.. We are now running the leopard 4082 2000kv with the 180amp esc and upgraded flexshaft all from OSE...I from now on will be using Dinogy lipos..for the price YOU cant beat the quality or the warranty ! ..... we just moved are battery trays forward ...the new setup is stupid fast... DJ

[Barrel Roll Joe]

IMG_0614.jpgIMG_0818.jpgIMG_0824.jpgIMG_0822.jpg

Not sure if these will help. I was able to tuck my rudder as much as it would go without having the pushrod touch the bracket. Just loosened stock bolts adjusted rudder then tightened, seems secure.

[lenny]

Thank you.
How is yours running for you ?
And is that stock setup in it ?

[Barrel Roll Joe]

Runs good, only have ran it four times so far and its pretty much stock except for the prop and shaft. trying to work out the bounce as well. gonna try and make this boat a monster and by the looks of the videos im gonna need to do my homework when it comes to choosing the right motor. 4074 or 4082 seems to be the question?

[olwarbirds]

leopard 4082 1800-2000kv for 6s...2000-2200kv for 4s....we did not have to tuck the rudder to take out the bounce...are BJ29 runs extremely smooth...(no bounce) with the 2 3s lipos moved forward...

[lenny]

Hi,
Where is the boat strut set at ?
And do you have any pictures of the setup with cells in place for no bounce ?
Also any video's of it running ?

[olwarbirds]

Hi,
Where is the boat strut set at ?
And do you have any pictures of the setup with cells in place for no bounce ?
Also any video's of it running ?

Hi Lenny.... strut is even with the transom no pitch....lipos (2 3S) back of batteries are even with motor mount, so they are way forward of stock mounting position...sorry no pics yet..got new digicam but with workn two jobs NO TIME to play...in both vids the BJ29 is still being run on the stock motor and esc, using 2 3S 40C lipos....we are now running a leopard 4082 2000kv 180amp seaking with cap bank and 2 3S 65C lipos...I will try to get new vids soon .... DJ

http://www.youtube.com/watch?v=6A7MWH_l_aE

http://www.youtube.com/watch?v=RZQmYMmJ3Sc

[Barrel Roll Joe]

hey warbird...you have that leopard wired with 5.5 bullets? if so is it wired exactly like the stock setup? about to order that esc motor combo you have just wondering if i should replace connectors with bullets.

Hi Lenny.... strut is even with the transom no pitch....lipos (2 3S) back of batteries are even with motor mount, so they are way forward of stock mounting position...sorry no pics yet..got new digicam but with workn two jobs NO TIME to play...in both vids the BJ29 is still being run on the stock motor and esc, using 2 3S 40C lipos....we are now running a leopard 4082 2000kv 180amp seaking with cap bank and 2 3S 65C lipos...I will try to get new vids soon .... DJ

http://www.youtube.com/watch?v=6A7MWH_l_aE

http://www.youtube.com/watch?v=RZQmYMmJ3Sc

[lenny]

Put 5.5 on everything,
What s cells are you thinking of running with the setup ?
And on what kv motor ?

hey warbird...you have that leopard wired with 5.5 bullets? if so is it wired exactly like the stock setup? about to order that esc motor combo you have just wondering if i should replace connectors with bullets.

[Barrel Roll Joe]

180amp seaking with cap bank, leopard 4082 2000kv on 6s. just wondering i guess i have to make a jumper wire with 5.5 bullets to link the batts together?

[lenny]

That kv is very high for 6s,
You will be stressing that setup if you do not run a small prop.
And then it still will be pushing very high rpm 44.400 on the bearings of the motor and maxing out the esc to.
Is it just going to be used for saw runs ?

[Barrel Roll Joe]

Isn't this the setup olwarbirds is suggesting? Just looking to make it fassssst as possible on 6s. I saw on YouTube someone was using Leo 4074 1400 kv with the seaking 180 and it looked super fast. What would you suggest?

[olwarbirds]

To clarify....the stock setup has impedance problems not the leopard setup....We are running a leopard 4082 2000KV with 180amp seaking with cap bank on 6S...with NO heat or meltdown problems at all....We do have separate cooling lines for the motor and esc.....I made up series connectors using ec5 connectors...I just personally dont like using straight bullets to hookup batteries..but thats a personal touch..each to their own madness...anytime Im using more than a 6S total setup I use xt60 connectors...something ive been doing since I became a EDF Jet junkie running high output (200amps + is very common)...seen a mishap with using just bullets to hook up lipos....(guy lost part of his hand, right next to me).....hope that clarifies the misunderstanding of what we are running... DJ

[olwarbirds]

180amp seaking with cap bank, leopard 4082 2000kv on 6s. just wondering i guess i have to make a jumper wire with 5.5 bullets to link the batts together?

Joe, we used 10GA wire for our leopard setup...and yes 5.5 bullets would work....heads up its stupid fast....but the hull can handle it...just take the time to tune it right....its not that hard of a boat to get running smoothly...those vids I posted were runs 2 and 3 on the stock setup ....sorry for delay in responses...I work two jobs...one at VA hospital other at hobby shop so spare time is short...hope to run and get vids this weekend if the weather permits... DJ

[Barrel Roll Joe]

DJ, thanks for the info I plan on running 5.5's on the motor wire and ec5 on battery connections. What prop are you finding works the best? Im looking to get some dinogy 3s batts. I have two venom 5000 35c to start off with.

[olwarbirds]

Joe, be careful with those venom 35c lipos, that leopard 4082 2000kv is a amp hog, we have puffed a couple of the venom 40c...id use the stock prop with those venoms...we are planning on doing some test runs with diff props tomorrow (weather permitting)...We did split are cooling lines so that the motor and the esc had seperate water supplies...all we did was use a vacuum line splitters...eventually we are gonna use a rudder with dual water pickups...

[Barrel Roll Joe]

Thanks for the heads up just ordered a couple of dinogy 65c. Did you have any luck testing props?

[AlanD]

Olwarbirds, I made some battery pack supports out of Styrofoam so the trailing edges of the batteries are in line with the front end of the stock wood battery trays. This moved my COG forward by about 3 inches. I also lowered the prop strut 1/4 inch below neutral.

This made a HUGE improvement in eliminating the bouncing. I have a little bouncing when at 100% throttle and it runs fast considering everything else is stock. I think I'll be able to trim that out by playing with the strut angle.

I still want to see pics of your setup though.

[jeffrey1]

what i did was lower shaft a little and made custom bett.trays works well.it will sometimes buck alitttle but not nearly as bad as stock.

[olwarbirds]

Thanks for the heads up just ordered a couple of dinogy 65c. Did you have any luck testing props?

YW, yes we did try a couple of props out...to our surprise the one that gave the best bang for the buck was a cnc from OSE.. part# cnc-4514251 not bad considering its only 20$...we havnt tried any sharpened/balanced berylium copper props yet...had to many boats to test ... found out too late i had my digicam setup wrong and ran out of memory...but we did get a few saw runs in later in trout stream at home... will try to post those vids soon...DJ

[olwarbirds]

We did the same thing for batt trays..made some out of styro...yes it does occassionally buck a little but you have to consider the speeds we are running on 6S..for the most it handles just fine for a cat with no hull or running hardware mods...just prop/motor/esc....had a great day on the water yesterday :) got to run several of my fleet, with new upgrades....ive got the FE sickness bad !!!! .... DJ

[AlanD]

Since we're talking about the BJ29 on this thread, has anyone else had problems with water getting in the motor/battery area? I tape my hatch every time so its not that, and I taped over the drain plug thinking it may be leaking but I'm still getting a lot of water in that area. It's not the water outlet either because I put paper towels around it and against the transom. I can squeeze about a quarter cup of water from the transom.towel after a 6 minute fast run. My next step is to remove and silicon behind the strut bracket.

The starboard battery tray is sprayed with water yet the towel around the water outlet is dry. All water hoses have good seals and show no signs of leaks. I also put a rolled up paper towel under the stuffing box and its wet as expected, but can it be letting that much water in?

[tlandauer]

Any leaks around the motor jacket? Do a test: disconnect the hose from the rudder, find yourself a syringe, pump water into the hose until you see water coming out of the outlet, now use your finger to block the outlet and continue to pump, you should feel pressure from the syringe and the outlet, when you release from the outlet, water should shoot out.
should also do a static test, load up with batteries and put boat in a tub or pool for several minutes and check for leaks. If your strut bracket attachment is leaking, you should be able to see water collecting near the transom. Also check if there is any tear on the rudder rod boot.
You said "SPRAY", the evidence of spraying is if the water is mixed with grease ( if you use those blue greases) and you see the mist of the mixture, then it ( water) is coming thru from your stuffing tube. Cut a very short piece of the same silicone hose and place it over the stuffing tube and between collet. DSCN1824_1330.jpg
I used another larger tube to "collar down" the silicone tube but if you have the right size , it is not needed.