head of the river cat hull thread

[Jesse J]

Good point. I have found when going from medium to really fast boats, that I need to beef up the rudder linkage. Instead of 1/6" piano wire, I now use .078" piano wire, the next size up. High torque servos and metal servo horns. Get the heavy duty dubros and like the man said, no slop.

[BIGDG357]

Thanks Jesse, I don't think there is a direct simple answer.I should be alright with the space to be able to move the batteries there is plenty. As far as the bilge I will install some carbon fiber in the sponsons to try to keep the batteries dry as the sponson battery mounting will give me the most range movement. Thanks for the help and good luck with the intruder I'll be watching the build.

[BIGDG357]

with the 8xl on 4s with a x640-642 should see you in the high 40s to low 50s, with the inline rudder they can get fairly twitchy at that speed so make sure your steering servo,steering rod are set up well with no slop
nice build by the way

AH HA, that was the next question I am wanting to run it with the pull-pull set -up with 2 linkage rods. I am thinking this should be the optimal set- up for having no slop(but I could be wrong) any suggestions on a servo I know it will have to be low profile and with the inline rudder torque will probrably be an issue also right?

[ozzie-crawl]

this maybe just preference but i like high torque servos but not high speed, yes the dubro heavy duty quick links with 4/40 rod work really well
have ran these hulls mainly with 6xl and 7xl have had speeds over 60 mph but they are barely hanging on at those speeds a 7xl with a 440/3 gives constant 55mph with good temps after 3 min
have run 4s1p and 4s2p, just remember when setting up c.o.g to measure from back of sponsons not transom on this hull
scott

[BIGDG357]

this maybe just preference but i like high torque servos but not high speed, yes the dubro heavy duty quick links with 4/40 rod work really well
have ran these hulls mainly with 6xl and 7xl have had speeds over 60 mph but they are barely hanging on at those speeds a 7xl with a 440/3 gives constant 55mph with good temps after 3 min
have run 4s1p and 4s2p, just remember when setting up c.o.g to measure from back of sponsons not transom on this hull
scott

do you think the pull - pull set-up would be worth doing or should I lay the servo down and use one linkage?

[ozzie-crawl]

push pulls can work well if they fit just not sure of the low profile servos durability, mine works well with a lay down servo i have it setup so it pulls the rod when turning right

[BIGDG357]

yeah I thought it would be a bit tricky to fit the servo standing up I just think the double rods look like the real cats ,oh well just a thought but thanks alot for the help guys I'll keep you posted on the build not sure how long that will be though. I'm waiting on Steve's hardware to return to stock, kinda set on the inline cat hardware but don,t know how long I can wait on it haha

[sailr]

That is a sweet looking water jacket and motor mount. Where did you get them?

thanks again guys this is what I have so far from out of the box to now.This is the motor placement that I figued the batteries could easily correct if its not perfect I think its pretty close though. Oh, and thanks tunda but I think I'll wait for the OSE set-up with the .150 flex

[sailr]

The low profile servos are made to mount in wings of airplanes for aileron control. Not sure of their strength. Read the specs on them and decide from there.

push pulls can work well if they fit just not sure of the low profile servos durability, mine works well with a lay down servo i have it setup so it pulls the rod when turning right

[bonewar]

AH HA, that was the next question I am wanting to run it with the pull-pull set -up with 2 linkage rods. I am thinking this should be the optimal set- up for having no slop(but I could be wrong) any suggestions on a servo I know it will have to be low profile and with the inline rudder torque will probrably be an issue also right?

BIGDG357, Mate i 'm running a twin MARITIMO, the servo i use is a futaba digital (s9551) , I have it set up in the hull standing up with wire run throw plastic tube to the rudder( pull ,pull). The servo is very strong and i have not had any problems with driving the hull at almost full throttle around a corner. The servo is a low profile type and will fit under your hatch standing up. Using this servo there is no rudder slop at all. The dimension (40mm L-20mm W-25mm H) , TORQUE @ 6.0V=8.8KG. The only bad point is the cost. Anyway just an option. BONEWAR

[ksm2001]

Just received my white cat from HOTR yesterday, I'll be using my medusa 3680 2000kv along with the 180amp marine turnigy esc. I got the cat strut/rudder from HOTR also but have to change over the 4mm bushing to the 3/16 thanks to Peter Z's work . But was wondering if anyone is adding some fiberglass or plywood to the rudder mount area, it seems a bit thin there .

Ken

[BIGDG357]

That is a sweet looking water jacket and motor mount. Where did you get them?

the water jacket is new at kintec racing http://kintecracing.com/Supervee_27_upgrades.html I just got this in the mail today you can get them in blue or red anodize but I'm not a big anodize fan so I remove the anodizing from everything. the motor mount is from OSE but only the water cooled plate the mounts that this came with seemed a bit small so I got a sheet of carbon fiber and cut my own stringers out to support the xl feiago.

[BIGDG357]

BIGDG357, Mate i 'm running a twin MARITIMO, the servo i use is a futaba digital (s9551) , I have it set up in the hull standing up with wire run throw plastic tube to the rudder( pull ,pull). The servo is very strong and i have not had any problems with driving the hull at almost full throttle around a corner. The servo is a low profile type and will fit under your hatch standing up. Using this servo there is no rudder torque at all. The dimension (40mm L-20mm W-25mm H) , TORQUE @ 6.0V=8.8KG. The only bad point is the cost. Anyway just an option. BONEWAR

Do you have pics of this set-up I would really like to take a good look at how you set yours up.The thing about the servo is if it will work I don't mind the extra cost I only need someone to tell me the servo will work, torque wise.Also what linkages did you use for your pull pull set-up? thanks

[bonewar]

Servo

I used metal linkages to connect to the servo
(local hobby shop) , then run metal cable throw a plastic tube throw the back of the hull to the rudder. In the back of my hull there is styrene for flotation which made it very easy to run the plastic tubes . The styrene helps hold the plastic tubes in place. Also the linkages come with a threaded piece so that you can fine tune the cables so that the servo won't bind. I soldered the wire cable to the connectors (very strong ) . The servo has plenty of torque for your hull . here are a couple of pics for you to see what I'm talking about. BONEWAR

[Brushless55]

I bought one ARTR with hardware. I installed a Feigao 9XL, ETTI 125amp ESC, and a 2.4ghz TX. Take a look at the pic so you can see where to mount the motor.

Tony, do you have a video of your boat running?