Dumas ACE 17" sloop conversion to RC

[Frank v B]

Next on the board is a boat.  The little Ace sloop by Dumas.  Ordered it and it arrived this past week. $60.00.  Good deal.

https://www.greathobbies.com/productinfo/?prod_id=DUM1102&srsltid=AfmBOoq9IBbtEl7oTmF5iOouDOBDsuA3DI6uJ4ZA5PRtDsMBNZbcBjqX

Contemplated changes:
- will probably use a carbon rod for a mast instead of the hardwood dowel.
- will decide on the RC equipment when the sides and the bottom of the hull are in place but before the deck is glued.  Hatches will be decided then based on the access needed.
- will fibreglass the whole boat with thinned down epoxy.  It worked really well on the tug.
- installed the keel about an inch lower than the plans.  Added stability without adding weight.  The keel has a lead bulb at the bottom so it will have a big effect on stability.  In the photo the knife blade points to the designed depth of the keel....it is upside down and drying.


Frank

[Andy Hoffer]

Hey @Frank v B

Are you still eating dinner?!!

Andy

[Frank v B]

Now the customizing starts:
- need a hatch to access the radio.  Placed balsa stringers on either side of the main balsa center brace.  These will become the edge of the hatch.  The deck will be glued to it.  Photo 95 as built.  Photo 99 with the center brace cut.(red line).  The red arrow points to the servo rail.
- proper chain plates (side deck attachments for the main shrouds...to hold up the mast).  The plans show eye hooks.  Not right.  Used plate brass and glued it to the inside of the hull.  Red arrow on photo 97 points to the new chain plate.  Side view in photo 91
- proper rudder- used a deeper more modern spade shape, partially balanced.  The rudder shown on the plan is not balanced (no rudder area ahead of the rudder post). See photo 94.  Red arrow points to the rudder on the plan.
Will also move the rudder further back- more responsive/better tracking.

Frank

[Frank v B]

Before putting the deck on:

- SERVOS: added 3 servos- one for the rudder, one for the jib and one for the mainsail.  The servos were HS 81's
- RUDDER: installed the rudder post about an inch behind the location on the plans.
- SHEETS: installed tubes for the jib sheet, main sheet, rudder pushrod.

Going further
- replaced the mast dowel (12 grams) with a carbon rod (9 grams)
- replaced the main boom at half the weight.
- replaced the mahogany deck with hardish 1/8" balsa wood.  I have decided to fibreglass the hull for waterproofing reasons.  For those who have built a boat before you will understand that water gets in everywhere no matter how tight the joints.  The old deck blanks were 49 grams.  The balsa deck is 23 grams.
- gave it two coats of 50% thinned epoxy on the inside for waterproofing reasons.  Thinned it with de-natured alcohol.

Frank

[Frank v B]

Photos of details:
1) Photo 52- the whole boat shot shows the three servos in the middle, the rudder post an inch behind the pre-drilled kit hole (at the point of the green arrow), the yellow rudder pushrod sleeve, the gloss of the epoxy coating inside.

2) Photo 99- the close-up of the jib sheet tube.  It is aluminum and runs up through the deck and through two hull formers.  The purpose is that if the boat takes on water at the front, the water will only exit into the open cockpit.  It will not be trapped inside the hull. The purpose of the tube is so the jib sheet will not hang up on the wood when it goes through the hull (theory).  Note: the  pencilled "X" on the white balsa is the location of the mast.

3) Photo 17- the close-up view of the 3 servos.  The main sheet servo is at the top, the rudder servo in the middle and jib servo at the bottom.

Frank

[Frank v B]

Fibreglassing the deck.

- added the deck one half at a time and pinned it down.  (photo 58)
- sanded it smooth.
- plugged the rudder post and the two rope exits with toothpicks.
- laid 3/4 oz cloth on top and brushed it out with 50/50 mix of finishing epoxy and de-natured alcohol.  Folded the glass over the edge and down the hull about 1/2" to seal the joint between the deck and hull. (photo 59) This system works beautifully and is described in the  video outlined in the footnote.

Once the deck has cured, I will cut out the hatch area.

Letting it cure overnight and glassing the hull tomorrow.

Frank

ps: Google "Fibreglassing tutorial with Greg Hahn" on how to do it.  A Model Aviation Magazine (AMA) sponsored video.  It is actually easier than the video leads you to believe. :-)

[Frank v B]

Could not wait until tomorrow.

Suspended the boat from a skyhook (put a screw into the ceiling), draped the fibreglass cloth over the hull and started brushing.
Applied 50/50 mix of 5 minute epoxy and denatured alcohol.  Used a disposable 2" brush.  Started in the middle and worked outward and downward.

Notice that the glass cloth is hanging down past the deck.  Will let it cure and then cut it off.  A lot easier and safer than doing it now.

Once dry, I will sand it smooth and apply another coat of epoxy.

Frank