Whiplash Sport 20 FE Build

[crabstick]

its looking good dude, I did exactly that before putting the deck skin on to get the Cog right.

Interesting ESC placement though.. I ended up running mine on top of the motor and a big sub cowl

[LuckyDuc]

Thanks. I'm not too keen on the ESC location either. What do you mean by a "sub cowl"?

[crabstick]

I will see if I have any pics, but basically I built a sub cowl, which is nothing to look at but it seals the boat, it has a hump in it over the motor and I tape down that cowl. Then I put my actual cowl over that. So the top cowl is purely cosmetic, the Sub cowl seals the boat.

[LuckyDuc]

Cool. I might do the same thing with mine.
I considered using my UL-1 lid to seal it. I could then mount the Whiplash canopy over it, and attach it to the hull like they do on the nitros (o-ring latches) That way you don't see the tape either.

[crabstick]

sounds like a good plan man!

[LuckyDuc]

Decking is done

The decking and front blocks are now glued on.

I test fit the decking and then drew an outline of the hull on it so I could trim the excess wood prior to gluing it to the hull. I found this easier than trimming /sanding after the decking is glued on. BTW. I didn't glue both sides of the decking at the same time. I did one side at a time.

The instructions do not mention when or how to install the two front wood blocks… So I decided to trim the decking overhang flush with frame #1. I then glued the blocks in place, making sure both the bottom and top of the blocks were slightly higher than the sheeting. I sanded them flush after the glue cured.

There are also two pieces of plywood that have a radius cut in them that matches the radius on the decking. The instructions do not mention these pieces either. I assume that their purpose is to reinforce the sheeting behind the sponsons. I also used them as a template when trimming the top decking to fit the hull. Pic below.

Next on the to do list is the sub cowl.

[LuckyDuc]

Glassing the seams.

While contemplating the “sub cowl” design, I began laying glass on the outside seams. My major concern with a wood hull such as this is having the seams split. So, I intend to double glass each of the outside seams with 1.5oz glass strips followed by another layer on the top, side, and bottom surfaces. As you can see in the picture below, I have laid the first strip on the top seams.

[LuckyDuc]

I started work on the sub-cowl. I decided to do 2 separate tape down sub cowls. The front sub cowl will be removed to replace batteries after each run. The rear sub cowl will only be removed when I need to re-lube the flex cable, or do work on the motor, servo, etc.

It is a 7 point tape down if I remove the entire cowl, but only 4 point if I just replace packs. The Whiplash cowl will fit over top of these and fasten like the traditional nitro cowls ( O-rings and front tab)

Next I will make the motor enclosure for the rear sub cowl.

[Ub Hauled]

great job man, great hints with the seams "how to".

[Ub Hauled]

where are you going to place the battery packs?

[LuckyDuc]

where are you going to place the battery packs?

In the nose like the pic below.

[LuckyDuc]

The enclosure box is now ready to be attached to the rear sub cowl. I originally built it as a triangle "ramp", but it was too high and didn't clear the fiber glass cowl... So I cut the height down and glued a flat piece on top.

It's not very pretty, but it's functional and will be hidden by the stock glass cowl anyway

[T.C.]

Where was the CG with the batt's in the sponsons ?
Looks to me the ESC could go up in front of the batt's if they were in the sponsons ?
Or between the batt's and the motor?
T.C.

[LuckyDuc]

Where was the CG with the batt's in the sponsons ?
Looks to me the ESC could go up in front of the batt's if they were in the sponsons ?
Or between the batt's and the motor?
T.C.

1 3/4 inch behind the sponsons with the packs laterally in the sponsons.

[LuckyDuc]

Getting back to work on the Whip 20

Now that I am caught up on my Whiplash 40, I will get back to work on my Whip 20 FE build.

FYI. Here is a picture of the two side by side.