Maiden voyage with upgraded Spartan.....

[Rcforever27]

Well got my Spartan wet today for the first time since changing all the drive hardware and motor/ esc over.... Ran good nonthing broke losened or fell off. With the exception of the motor collet loosening, (not a big deal) had the gps in and not very happy with the speed on 6s but everything was cool and no issues there. Will look into prolong up from a octura 447/3 to something with more speed potential. My gps read 34.5 mph.... :( but speed takes time . Still have some trimming out to do. She does chine walk or death wobble at higher speeds but that'll get worked out. And Kevin, jeffs .187 cable ROCKS!!! no problems here! Took the cable out after my run no heat issues or discoloration yet. There's still a large amount of grease on the cable but I'm gonna clean it off and re grease it. Just have to run that cable without the Teflon liner. As far as amp draw, couldn't confirm at this time still getting used to how the watts up meter works. All and all I'd say it was a successful voyage, with room to prop up for more speed. Special thanks to Jeff wholt, Kevin and all the people on this forum who have helped me! Any ideas on a "faster " prop? I'm running 6s lipos, seaking 180 & the leopard 1400kv motor.... Have the octura 447/3 prop currently with a speed if 34.5 mph.... Thanks! Also i had to higher the voltage cutoff to 3.2 volds as one if my packs had only 3% left and measured 9.87 volts at rest...... :thumbup1:

[dag-nabit]

Great to hear you are having success with the new setup, with the exception of your top speed. I find it hard to believe you aren't getting better speed with that prop. I assume you are running the 4082 1400kv and I would think that motor has enough torque to spin that prop.

Maybe try a an Octura 645, bit smaller diameter but more pitch.

I find the LVC on the T180 a bit of a challenge as well, after experimenting a bit I'm now using the 3.2v setting, which usually leaves about 15-18% residual capacity in the batteries. A bit lower than the 20% target, but if i use 3.4v setting the LVC is kicking in with 35-40% capacity left in the batteries, which is not providing reasonable run times.

It seems the T180 would benefit from a 3.3v LVC cut off setting.

Kevin

[Rcforever27]

Yeah i thought i would have had more speed with that setup but maybe i wasn't pushing it enough and i'n one if your other posts where you saudcsome times the gps lag makes for a wring or i'n accurate reading, could be my issue . But i am going to get tht prop you suggested. That was my initial reaction, get a smaller diameter prop with more pitch. But i still need to trim it out first. Thanks for your advice! And good luck with your Spartans ! Keep us posted as you always do! Cheers!!!

[Rcforever27]

Now the 645 prop, 3 blade ? "m"?"x"? Which exact one do you recommend? More speed with a 2 blade that size ? In theory?

[Rcforever27]

Hey Kevin, i also have a Prather 230 prop and a 235 prop, and an octura 440/3 prop , can i utilize any of those for more speed? Which would be best?

[dag-nabit]

In theory larger diameter or 3 blades will give you more surface area acting to move water past the prop, this will help get the hull moving, so should improve the hole shot and acceleration. Kind of like putting wider tires on a car to increase surface contact with the road and increase traction.

The style of the prop blade can also affect the amount of surface area (among other things). If I remember correctly X series props have more tongue on the prop blade which increases surface area, but also increases lift. This will make an X series prop more prone to prop walking by lifting the back of the boat.

M series props have less tongue, so you loose some surface area, but probably spin a bit easier, so you may gain a bit of motor efficiency. (extra RPM) when compared to the same spec X series prop.

Higher pitch will give you more forward momentum, i.e higher speed. Kind of like gearing up in a car. It will also give more lift, torque roll, and be more prone to prop walk.

But, you also need the power to spin the extra diameter and/or pitch without losing too many RPM's on the motor (loss of efficiency)

So the trick is to find the correct diameter to give you enough thrust to get the hull moving, and enough pitch to give you the forward speed you want, without loosing too much motor efficiency and losing RPM.

Unfortunately it is usually trial and error to find the right combination.

I think the 440/3 might be too small, but try it and see what results you get.

I don't have a prop chart in front of me, but I'm thinking the Prather 230 and 235 are getting into very big props, similar to your 447. A Prather 225 might work well. (I'm pushing the 50mph mark with a Prather 220 on 1700kv).

Of the props you have available I would start with the 230 or 440/3

Kevin

EDIT: I checked the Prather Charts. The 230 is 48mm x 76mm so it is larger than the 447 by 1mm on diameter and has almost 10mm more pitch. That should make your boat fly, if it can turn it, but i think it is too much prop and you are going to run into other problems like torque roll and prop walk. But you won't know until you try it.


That P230 calculates to 53 mph using 80% motor efficiency and 25% prop slip.


Kevin

[Rcforever27]

Ok thanks! Gonna orint this post for reference... I just posted on changing my motor to my leopard 1774 and gonna start with a octura 440/3 prop....

[dag-nabit]

Ok thanks! Gonna orint this post for reference... I just posted on changing my motor to my leopard 1774 and gonna start with a octura 440/3 prop....

Note that I edited my post to state I would start with the 230 or 440/3

Kevin

[Rcforever27]

Gotcha i just read it.... Thanks again:) I'll try. Both for sure!!