HK 41" Vanquish with CC 1717 1y 1580 Kv on 6s 2p I hope

[Wizliz]

Hello ttc. :)

Thank you for reply. Yes i am running on 6S (two 3S in series) the first four minutes in the video, sorry for beeing unclear. Second half (at 3:55) i am trying with smaller 4S (two 2S in series). My cooling is working very well and temperature is around 35-40 degrees celsius. Since yesterday i have received many tips and ideas on what todo, first thing i am going to try is to shorten the water inlet tube so that only a few mm is below the hull. As it is now it is almost 1,5cm below the hull and this might be what is causing the nose dive as it is causing drag. Several "boaters" have pointed this out to me. Will fix this today then well see if that helps...



Unfortunally weather is not so good atm so it might take a few days before i can test my boat again. Also i need to figure out a way to avoid radio interference for my rescue boat since it loose contact when other 2.4GHz radios are On... I certainly dont want to go swimming again, like i did sunday, after all it is still May and not long ago it was ice on the lake...

My motor mount is stock, if you like you can check my "Optimizing Vanquish Video" where i show the inside of my Vanquish and how i got it (almost) water tight with silicone at the backside and at the transom. It still gets a few drops of water through the shaft, but it is not a biggie.

I almost lost my boat when i did the maiden run, had very much water inside and i got affraid that i might loose all hw in a short out with a loud POFF... Thankfully everything survived and i decided to make that video so that others could avoid making the same misstake as i did. Before every run i allways tape down my hatch incase i get nose dives or flips upside down.

Will keep you posted. :)

Have a nice day

[Remmie81]

Wizliz,

That waterpickup will definately slow down the hull and cause drag on the left side of the hull.
Ive tested with such a waterpickup on my gas-engine boat. I only had it 1,5mm sticking underneath the hull and cost me approx 3-5km's of top speed.
Maybe you can make a prop blast pickup, that will give you the cooling you need and you will not have the drag/speed loss from the current waterpickup.

2nd thing I see on your picture are your trimtabs. It looks like they are flat with the bottom. This will cause the boat to run wet (and because of that it will have a lower topspeed and could give handling problems on straight and in turns (bow is pushed down))
The best thing to do is raise them 1,5mm were you mount them. Then set them to neutral position and drive your boat and see what a difference it will make.

Hope these tips will help you making your boat faster!

[martin]

You need to check a few things on your set up ie how much hook is in the hull, is the stinger down at the prop end (set to neutral), set tabs at neutral & up from the hull bottom as Remmie said. Where is your cg, a starting point on this hull would be around 12.5" or 316mm in from the transome ie 30%. This is all assuming you dont have motor or esc problems of some sort.

[Wizliz]

THANK YOU GUYS!!!

As per your advice i have adjusted and i just got home from a test run. Boat is moving much better now and i have just finished uploading a small clip where you can see the difference. But i think that there is still room for improvement. I noticed that at high speeds it starts to wobble a bit sideways, i hope something can be done about that aswell. Batteries are not "where they should be" ie at CoG 30%. I am thinking that i should probably try that setup one more time, to see if things have improved there aswell.

Now i can go to bed having a good nights sleep. Ohhh and yes, yesterday I forgot to say thank you TryingToCrash for letting me "borrow" your Vanquish thread. Hope you dont mind.

Cheers!

[Basstronics]

Stupid question- is your driveline free? If there is tension or pressure on the cable at some point it could cause enough drag to slow her down.

[tryinotocrash]

That is a little better for sure. Still stuffing the nose too much and you have low rpm not churning and burning like it should. The bottom of the trim plates should be up from the bottom of the hull by a couple of MM meaning you should be able to measure from the hull bottom to the bottom of the plate where it meets the hull and there should be a gap so that when the boat is on plane trim plates don't touch the water .As described by Remmie. Also when you get the other prop on the boat you will see a difference of lift I hope . I don't understand how you could be at 25 volts and the motor isn't sounding like you are anywhere near 40000 rpm ,according to your motor specs if you were running 25.2 volts you should be getting 40000 rpms. I don't want to sound like I don't believe you but you have two 3cells positive to negative then one positive and one negative from each battery to the esc?? Oh and no sweat on the thread jacking life is short and we are all here for the same reason , to help and get help.. Oh and don't forget to grease your flex cable frequently as well. Grease it often.. Mark

[tryinotocrash]

You beat me I was typing

[Wizliz]

Stupid question- is your driveline free? If there is tension or pressure on the cable at some point it could cause enough drag to slow her down.

Hmm you might be on to something there Basstronic! Yesterday i noticed that there are tiny speckles of metall inside the boat. Perhaps my driveline is to tight? What is the recommended fitting "tightness" for the driveline?

Regarding my trim tabs, it would require demounting and then some Dremmel tool to make the holes/slides longer since they are allready at their highest setting. Will get right on it.

As for power i am using my Traxxas acks and standard Traxxas serial connector same as in my E-revo so it is 6S@5000mAh.



I have another two identical acks, and my plan was to eventually test out 2x3S in serial + 2x3S in serial and then parallell for 6S with 10000mAh instead of 5000mAh in above picture. But not until i get the boat running better (two parallell connectors to one serial) That is if cables does not melt and the Vanquish can handle the extra weight (1.6KG instead of 800gr) LOL. But one thing at a time...



Best regards
Magnus

[Remmie81]

Hi Magnus,

Yes please remove the trimtabs and adjust the holes. If you can mount them 1,5mm higher then the bottom that will make a huge difference.
Just make sure they are at a 90degree angle looking from your transom. So in other words: Set neutral.
Then drive your boat again (but be carefull as it can handle very different). When it runs too loose, adjust the tabs with the adjust screw and set them a little bit lowe. (like half a mm) and test again untill you get the result you want.

Good luck!

[martin]

Ive just noticed the prop you have on their, is that the prop you have been using during testing. A 48mm 3 blader is way to much prop which is keeping the rpm down & not letting the boat come up out of the water. Much improved though on your earlier set up though after some good set up tips.

[Wizliz]

Update...

Good news! Today i received the chinese made pro boat prop i ordered a week ago from US. Rather good delivery times compared to ordering from asia... :-) I also beleive that basstronic was SPOT ON on what was causing the bad performance!

To start with the shaft adapter was way too tight against the water cooled motor mount so i have adjusted that (it has grinded metall!). Secondly the plastic (teflon?) tube inside the brass tube was too long so when accellerating i beleive that the shaft adapter was grinding against the plastic tube causing a slowdown (see below Pic 1) and also made the plastic/teflon tube to rotate inside brass tube which caused friction that slowed the boat down considerably.


Pic 1 Before


Pic 2 After


I also made sure to "lube it up" real good since i had noticed metall fragments and that the flex shaft tube was very hot!...

Went down to the lake and was hopeing for a good run.

Then it happend...
(here comes the bad news)
The flex shaft snapped! I suspect this happend due to that the flex shaft tubing was loose due to bad factory mounting which in turn caused the whole tube to wiggle/roll around inside the boat and that made the flex shaft unstable and it snapped within a second!...

Now the flex shaft tube is looking like the end of a trumpet!... Dont know if that is cause for a total change of the flex shaft tube aswell. Anyways i have ordered a new flex shaft and some super lube so now i have to wait for that to arrive and then i have to figure out how to replace and fasten the new flex shaft to the shaft adapter. I have all this spectacle on video but have not been so eager to upload it, since it contains some "salty swedish language"... perhaps later when i have edited some of the ...

[tryinotocrash]

Well Wizliz the saga continues. Those flex shafts are not very good to start with. Go to OSE parts and get a new shaft with the hard end on it already I bought the .187 x 18" one and cut the flex off to the length I needed. You will have to file a flat on the threaded end for the drive dog and leave a .187 gap between teflon washer and stinger. I also opted for the thrust bearing between the motor and drive adapter. The new flex from OSE has bigger wires in it than the stock one so I am hoping for longer life. Sounds like we are having similar struggles. I have been having better luck now but only time will tell. Next step for me is to gut the whole boat and beef up the insides with carbon fibre cloth and a new beefy motor mount. Send a pic of the stuffing tube if you have time.

[Chuck E Cheese]

after reading this i am a little concerned. do you guys really think a 40-82 is enough motor for this hull? thats the size motor i use in a 31" hull (neu 1521)... just saying... i just recieved some parts and am going to be starting a vanquish build. i have had a brand new hull sitting around for about a year and am starting to get back into boating. the difference is i plan on using a 56-92 motor in mine.. i havent started it yet but will start a build thread and keep ya posted on how its going.. just saying, 4082, really???

[martin]

The 4082 motor is on the small size for this boat but its the easiest motor to use as well as the 4092 without major rebuilding to take something like a 5692 motor, also a lot cheaper than going to the 5692. Just depends how much money you want to spend on upgrades, having said that their have been a few on here that have used the 4082 in the Osprey (better hull in my opinion build wise) that are running 55-56mph. Ive also seen an Osprey with 5692 motor running around 50mph on here.

[martin]

The 4082 motor generally uses around a 45mm diam 2 bladed prop, the prop fitted to this boat 48mm diam 3 blade will kill the rpm on this motor.