Fixing the BJ26 Handling Issues

[Joe007]

Propnutt, I agree with you that you need some flex for adjusting the prop ange.. Cut my stuffing tube just at stern... I have about 1 1/2 inch of flex tubing to make a adjustment.... Will post some pictures in the near future... Waiting for a new flex shaft I had a brain fart this morning and cut the shaft same as the stock one....
Joe007

[Apples1]

Those batts look a little dodgey propnut,anyhing with the word zippy in it make me shudder. they probabley need to 25c continues amp draw not 20, and also the cheaper the internal cells are the more likely they are to go "puff" and "boom",
My best advice is get the best you can afford, if that is your budget then go for it, they will still be ok, but you may have to replace them more frequently.

I have just made the step to lipo in the last 2 weeks, you wont regret it.
i got mine at Rclipos.com

[TRUNKMUNKY]

TRUNKMUNKY,

Would like to know what hull mods you have made, how to do them, pictures if possible. Your boat definitely turns great! Awesome video too! Please enlighten us.

Also, are these the batteries you are running? And is this where you got them?

http://www.hobbycity.com/hobbycity/s...idProduct=6656

Been dying to get some lipos and these look very affordable. The weight loss has got to help the handling.

For the hull mod I added a couple pieces of ply to cover the last step on the rearmost sponson,with good results, About the lipo batts,yes,those came from united,and were a bargin for the money.so I thought I would try them and have to say they are very good packs compared to some of the higherdollar packs I have.Only 20c 30c burst output ,so not the most powerful but as the video shows,still good bang for the buck,no signs of puffing or swelling after 3 charges,but I balanced charged them every time to be safe.Any lipo pack can puff and swell if the boat setup is not right or are mishandled or not charged properly .This setup for my BJ runs faster than stock,handles way better and runs very cool.Any good 7.4 pack with this setup will work great.If your new to lipo power,buy the best you can afford, and a good balance charger.Just showing what this setup will do for the handling problem not endorsing any one's batts.

[Joe007]

apples1... Were you running the stock hardware on your cat or do you have aftermarket? Propnutt stated that he used Fuller's hardware... So we can all learn from one another..
Joe007

[ETOWNE]

For the hull mod I added a couple pieces of ply to cover the last step on the rearmost sponson,with good results, About the lipo batts,yes,those came from united,and were a bargin for the money.so I thought I would try them and have to say they are very good packs compared to some of the higherdollar packs I have.Only 20c 30c burst output ,so not the most powerful but as the video shows,still good bang for the buck,no signs of puffing or swelling after 3 charges,but I balanced charged them every time to be safe.Any lipo pack can puff and swell if the boat setup is not right or are mishandled or not charged properly .This setup for my BJ runs faster than stock,handles way better and runs very cool.Any good 7.4 pack with this setup will work great.If your new to lipo power,buy the best you can afford, and a good balance charger.Just showing what this setup will do for the handling problem not endorsing any one's batts.

I looked around and I couldn't find anything. What prop are you using ?

[TRUNKMUNKY]

I looked around and I couldn't find anything. What prop are you using ?

Not sure about the first part, of the question,but Im using the cen racing prop 42 mm.

[ETOWNE]

Not sure about the first part..............cen racing prop 42 mm.

I looked at all your post, thanks.

[Apples1]

i was running stock setup, but am in the process of upgrading.

[PropNutt43]

Those batts look a little dodgey propnut,anyhing with the word zippy in it make me shudder. they probabley need to 25c continues amp draw not 20, and also the cheaper the internal cells are the more likely they are to go "puff" and "boom",
My best advice is get the best you can afford, if that is your budget then go for it, they will still be ok, but you may have to replace them more frequently.

I have just made the step to lipo in the last 2 weeks, you wont regret it.
i got mine at Rclipos.com

Well I took a chance and ordered a pair of these Zippy K 7.4 Lipo packs:

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=6656

Showed up about 4 business days later. I have to say I'm impressed about their fast service and the quality of these batteries.

I figured at 20c that’s 86 amps and 30c burst of 129 amps they should be fine. I'm still running the stock esc rated at 45 amp - 55 amp peak and stock motor rated about the same so they shouldn't even come close to maxing these batteries out.

Got one run in today after work with these and man what a difference! Had the esc motor timing set on high. This thing really zings now and the handling has improved greatly with the loss of about 3/4 lb. The best part is these batteries barely got luke warm.

Highly recommend going Lipo both for the speed and handling.

[Wakesurfer]

Made a few mods to my boat and gave it a run today. Probably should make one change and a time, but I went after it this time. Swapped the stock drive for the TLR Skater II. Had to trim about 3/16" off the shaft, and cut one of the stock screws. Blind nut was spinning. Turned the tracking fins to match the angle of the hull. Prop changed to Octura M435 3 blade. TLR balanced and speed bead finish. pulled the stock battery trays and expoxied in new ones. 3/16" balsa running from 1/4" back at the front of the tray to about an inch from the transom. Gives me a little room to adjust CG. I was able to bend the stuffing tube up about 3/16" which lined the shaft up perfect to the strut on the Skater. I set the MaxAmps 2s 8ks back 1 1/4" from stock. Water had very small ripple at the park. The new prop seems to cavitate on the hole shot. Had to feed the throttle in easy to get the boat to plane out. Once it settled on plane throttle response was great and it looked faster on the water. Still some list in the tighter turns, but much better than stock handling. Next I'd like to shorten the T fins a bit. The bad news: Rudder hinge pin came loose and went to the bottom of the lake. As soon as it dropped the boat made a 90 deg turn and flipped. A fisherman who seemed thrilled about getting to see a FE boat run tied on a heavy spinner bait and made the rescue cast. Another guy rigged for cat fish came from the other side of the lake to see if he could help too. Got it home and made a new hinge pin from an 1/8" bit and stole a grub screw from a truck pinion to replace the missing one. Put it all back together with blue Lock-tight this time. Next mods: shorten the fins, switch to the Hyda 120a with external BEC or Rx pack, hang the Novak HV6.5 ot the Fiegao 7xl, or maybe the Nue 1512 1Y. Might be tuff to find a cooler for the Neu ribbed can though. Need to make an adapter to parallel the new 3S 8k packs, or steal one from my 3905s for series. How fast will this thing go with a 2380kv motor on 6 cell? Need more prop too I suppose.

[MAXAMUS]

Hi all another newbie enters the blackjack world lol

well I'm just waiting on mine arriving should be here any day now Ive read all the pages and have found a lot of valuable information and made notes !!

so I'm going lipo from the start as i have lipo's from my RC aircraft although Ive had to buy 2s as i have 3s and 4s just now. So can i expect to take her out the box grease and tape her up and have a blast or not ???? which brings me on to a few questions lol

1
i have a mega motor 16/25/2 would this work as an upgrade possibly in the future ? spec Specification
Weight 111 g
No load current Io 1.1
Size 28x41,5 φ x L mm
No load 2650 RPM/V
Max. current 35 A
Number of cells 4 - 16
Max. diameter 28 mm
Diameter of shaft 3,2 mm
Max speed 55 000 revolution/min

2
with the stock set up can i change the prop ? and what should i get

3
how many cell (lipo) can the stock set up take IE can i use a pair of 3s


sorry for so many questions but the more info you get the better it helps you understand this little rocket i can see the ££ signs fluttering in front of me already with all the mods that will inevitably be required as i get more and more comfortable with it

Maxamus.............

[PropNutt43]

MAXAMUS

A pair of 2s packs will work fine with the stock setup until you can upgrade. Just make sure they are a minimum of 20c to 25c rated and at least 4000 mAh or they might puff or well you know. The loss in weight will definitely help the handling.

I wouldn't attempt using 2 3s packs because the esc is not rated for that high of voltage, I believe 21v is the max.

The motor you mentioned is actually smaller in diameter than the stock one and the shaft is not 5mm so it won't match up and probably won't have enough power.

And yes, you can use other props on the stock drive because it comes with a 3/16 shaft adapter. But you won't be able to go much larger than 42mm or it might hit. Suggest x642 or x442 from Octura.

Welcome aboard and enjoy!

[MAXAMUS]

propnutt
thanks for the lipo advice but could you not use 3s packs or indeed 4s packs if you were to wire in parallel as voltage would stay the same 11.1v and mah would increase but then weight would become an issue i'am on to a prop thanks but just got a phone call last night to say there is a 3 week waiting time and its on back order ! well will give me time to prepare and absorb information

[PropNutt43]

If you run the batteries in parallel they will work fine. 4s packs would be better because you might hit the low voltage cutoff too easy with the 3s packs, because the esc needs a minimum of 10v. Also you will lose a lot of speed with the lower voltage packs.

With the batteries parallel you probably won't lose any weight but should get much longer run times. For me the weight loss is the bigger advantage when running Lipos because it helps the boat handle so much better.

In a review on RC Universe there is some video footage of a completely stock BJ26 running 2s packs. Here's the link:

http://www.rcuniverse.com/magazine/article_display.cfm?article_id=970

[calcagno45]

PropNutt- Did you have a chance to run the packs more? Also what balancing tabs does it come with? HP/PQ?