Yes, another Catamaran Build!

[bonewar]

ACE Good job dude, I love the side profile of your cat it looks fast just siting there. Are you going to paint her (what color). The hatch has turn out good, it looks scale , and i like your idea on the drives, Keep up the good work mate. And thanks for the comments on my cat . BONEWAR

[peells]

Did you coat the hatch with epoxy yet ? something looks different.

[ace028]

Bonewar, thanks, I think I will paint it some shade of red or orange (my dad will paint it I mean) I would like to get it ready for the water to test it, then strip it down and paint.

I coated the styrofoam with epoxy, but ran out, so I am still waiting for the order to come in, I have a very thin coat on now, but it will be built up in thin coats till the desired thickness of epoxy is reached.

I did however get the servo in today! Hitec HS81!! Should have plenty of torque to turn this little guy.

[peells]

I could just make a longer boom for the rudder to mount on!!! but you ll need to tell me how long, I also have a rudder blade made that might work better for you!!

Dad

[ace028]

Finally more progress... I guess

I was trying to figure out what to do to get the rudder to be even with the props or a little bit behind them, so here is what I came up with. I made a standoff sort of like real offshore cat, semi scale. It still needs some sanding, and shaping, keep in mind that nothing is tightned, just sitting there for the pic. This was sort of hard to do to keep it symetrical, this should have been done from the beginning to make everything easier, but I guess that is the price you pay for custom and scratch builds. lol

What do you guys think?

I am still waiting on my epoxy and my struts.

[peells]

I like it, it looks nice, and you gave it some great lines, now you have to mount the servo and test the swing of the rudder!! you might like your rubber boot on the outside for the rudder control rod.

[ace028]

I am going to mount the boot on the inside. I am waiting for my epoxy so that I can lay some fiberglass in the bottom to stiffen it up some. This is going to end up being a heavy micro, which will be good I guess with all the power it will have to help keep it one the water. I am pretty sure that I am going to keep it 2 cell lipo or at least start there.

Speaking of lipos, when you run two motors and escs, is it best to run the power leads in parallel on the escs and batts for a shared battery like 2s2p. Or to just keep the batts and escs seperate. I am sort of leaning tward 2s2p and running the escs power lines in parallel to make the power equal from side to side, and input?

[peells]

well it looks like you and I are the only ones talking! parallel should be OK, but you may want to consider running separate systems for a couple of reasons 1. wire routing 2. wire length due to limited space, but if you were running one motor (and you are not) I would say yes most defiantly run the two packs in parallel as it would extend the run time by 2 times give or take. 3. two separate systems lends its self to better isolation for trouble shooting say a transistor or diode Fry's in an esc and there is no visible burn marks it might shut you down if it shorted and it might save the other battery from harm so if you loose one side at least the other is safe

[Simon.O.]

Peter, that is an interesting take on twin power setups.
I am looking at a twin, at the moment it is all info gathering.
I am planning to go 4S2P onto a common block then take the esc's power from there. This way I get the same power to both speedies.
If both packs are charged as 4S2P and then run as separate systems this should give the same result, I hope. It would depend on the condition of the packs and rely on them to both be matched for discharge performance.
I am wanting to avoid differential thrust.
When it comes closer to the time I will setup a separate discussion thread for twin power systems.

[ace028]

Simon, I agree, I was concerned that by having the power systems seperate, that maybe one battery would have more mah or something like that thus producing more thrust or less thrust per side, I thought it may be better to "equalize" both sides by running all power lines in parallel. I look forward to your discussion, I will need to power my boat soon.

[peells]

Simon is this what you have in mind? see attachment

[lomdel]

What would you use as a terminal block? Pics please!

[peells]

I was just trying to see if the sketch I am showing is something like Simon had in mind,
You could probably pick up something that would work fine at radio shack or an automotive supply, Myself I would just make something with as few plugs as possible two in two out, You could actually do it with just the plugs and wires, but it might get a little messy, I may just attempt making a little something since we are talking about it I got an idea.

[Simon.O.]

Peter, that is pretty much what I had in mind.

Doing it with a terminal block that will be compatible with Deans conectors would not be too hard. A fair bit of beautiful brasswork could be done.

If you are using bullets all round I could still fab up a "manifold" for all the power in and out points.

I'll see if I can mock something up later today.

This is also on the discussion here, worth following.
http://forums.offshoreelectrics.com/...8687#post78687

[peells]

I just may make up a little something as well because the same setup used for two motors would work for one (not that you would need to) but it could be a handy little item to have around, and I have some brass flat stock and bullets