Steering servo mounts on big blocks

[Tony Jacuzzi]

How are you guys running twins and big blocks mounting your steering servos? Upright or lay down, I like to lay them on their side in most of my builds but I was wondering if there were any issues with the bottom skin being too thin and flexing with the big weight of the boats, high speed of the boats and the high torque of the servo? Any pictures would be appreciated. Thansk tony J.

 

[Don Ferrette]

T-

I typically make mine and always lay the servo on it's side. Make two hardwood blocks the same height as servo sides notched for mounting ears (with mount rubbers in place) and servo wires. Take a piece of high grade 1/8" ply and set the servo with blocks on it and trace out the overall outline also marking the block locations. Add roughly 1/8" to outside dimensions, cut it out and sand the outer edges smooth. Epoxy the blocks to the board and when dry fit the servo into the now assembled mount, make a 1/2" wide strap from brass stock to go across the servo body and drill each end and the blocks for #6 cap screw. After determining final placement epoxy into the radio box. I typically will make it so the mount end facing the transom butts cleanly up against the rear wall of the radio box for added stiffness. During final assembly I will cut out a piece of thin padding (I like the black perforated tool box drawer liner for this) to place under the servo. Once strapped in place the servo will be firmly mounted with just enough insulation from the padding underneath and the mount bushings on the ears to isolate it from any severe transient vibrations that may develop. I will also generally use the same method for the throttle servos in the twins and in the second pic you can see the final install of both the throttle and steering servo with the brass strapping method. Been doing it this way for a long time and it has worked great!

 

[jeff baham]

i second don's suggestion. been do it for over 20 years myself, but for single engine 67's riggers , and i do the same thing with the standard servos to.

 

[Charles Perdue]

Just be careful with the bonding of the servo plate to the bottom of the boat. That is what just last weekend cost me my 20 rigger. The bond was good but the rigid servo plate peeled away from the flexible bottom of the boat. The bond was so good that it delaminated the CF bottom of the boat. I usually add button or flat head screws attaching the two together as added insurance. I did not this time . Wish that I had.

Charles

 

[Don Ferrette]

"The bond was good but the rigid servo plate peeled away from the flexible bottom of the boat."

That's kinda why I butt the servo tray up against the rear wall of the radio box. To peel away it has to lift, if it's bonded to the rear wall a well it makes it that much harder for that to occur.

 

[Rick Pirrone]

OT

Don could you please take another Photo of your Bell Crank Setup for the Throttle

Greg

hi greg

I set clints up pretty much the same way it keeps the pushrods nice n straght for the 91 vacs

shame the carb cant be rolled over to have the pushrods in the middle

cheers rick

 

[Rick Pirrone]

hi don

Do you have any distance issues with the Rx antenna wire in under the radio box????

cheers rick

 

[ButchLaPorte]

Tony u holding out on me . I have been getting the itch for a nitro twin . U going to beat me to it????????? lol

 

[ALLAN YUEN]

Tony What kind of twin rigger do you have? and Can you show me picture? ^_^

 

[Don Ferrette]

OT

Don could you please take another Photo of your Bell Crank Setup for the Throttle

Greg

I'm actually setting up the linkage for the new Crapshooter twin so here ya go-

 

[Terry Keeley]

 

[Don Ferrette]

hi don

Do you have any distance issues with the Rx antenna wire in under the radio box????

cheers rick

I run the antennas out of the box, usually about 7" above the lids.

 

[Brad Christy]

Tony,

What's wrong with the Crapshooter method?

Thanks. Brad.

Titan Racing Components

BlackJack Hydros

 

[Terry Keeley]

Nice mount terry

Thanks, nothing special, just 1/8" alum angle (architectural).

 

[Buckshot]

I found that gluing the servo mount directly to the floor of the tub would produce flex under load and erratic action even with throttle servos and especially with twin "bell crank" type setups directly mounted to the floor with big motors.

I use a similar method to Ferrette's for the steering but add one extra piece.

Two hardwood blocks with milled slots for the servo ears. Rear block is glued to the rear bulkhead and floor. Front block is glued to the floor then an added stiffener is installed to prevent the floor of the radio box from flexing at the front block.

 

[Tony Jacuzzi]

Buckshot:

Nicely done, I had this summer a servo mount glued to the bottom of a hull delaminate the plywood in a blow over, and actually pull the servo and ply free. As I was building this hull I was worried about the floor flex given the speed, weight etc involved with a 13 pound riggger hull

Brad - I like Stus method a lot, and it does eliminate then floor flex issue but it does seat the arm a little higher than I like. I stll might do that too

Thanks To everyone for their input

I found that gluing the servo mount directly to the floor of the tub would produce flex under load and erratic action even with throttle servos and especially with twin "bell crank" type setups directly mounted to the floor with big motors.

I use a similar method to Ferrette's for the steering but add one extra piece.

Two hardwood blocks with milled slots for the servo ears. Rear block is glued to the rear bulkhead and floor. Front block is glued to the floor then an added stiffener is installed to prevent the floor of the radio box from flexing at the front block.

 

[dave roach]

Tony

All you need to do is lower the two pieces for your liking.

And like Brad said I would use the mount Stu uses.

Dave Roach

 

[Don Ferrette]

Buckshot:

Nicely done, I had this summer a servo mount glued to the bottom of a hull delaminate the plywood in a blow over, and actually pull the servo and ply free. As I was building this hull I was worried about the floor flex given the speed, weight etc involved with a 13 pound riggger hull

Brad - I like Stus method a lot, and it does eliminate then floor flex issue but it does seat the arm a little higher than I like. I stll might do that too

Thanks To everyone for their input

If the servo mount is glued to the bottom without any tie in to a bulkhead either like Buck or I do they can pull away in a bad blowover.

 

[Brad Christy]

Tony,

Have you really looked at how much space is between the bottom of the servo and the floor of the radio box? If I lay a piece of 1/32" ply under the servo in my boat, the servo mount won't seat on the bridge rails. How much lower can you get?

Thanks. Brad.

Titan Racing Components

BlackJack Hydros