JAP/JAE .12G construction

[Geraghty]

I just got back from meeting Joe Solinger & picking up my motor mounts. Nice guy & nice workmanship. For those interested, the mounts are 55mm long (just under 2-1/4") and where the engine bolts up, the mounts are pre-tapped for 440 bolts. He also includes basic instructions on the packaging... NICE. Time to mount my engine!

Motor mount installation hint............ B)

After your motor is mounted to the plates and the motor and mount assembly are securely fastened in the boat,there should be noticable movement of the motor in the motor mount grommets.....This is exactly what you want.....The length of the standoffs is slightly longer than the width of the vibration isolation grommets. This movement allows for the vibration isolation.Let the motor float in the motor mount so the grommets can do their job.

This was a tough lesson learned..........

Our first JAP.12 SAW boat we built was equipped with a solid motor mount.Thinking the smaller .12 motors can't vibrate enough to cause a problem....right??....WRONG......the vibration of the .12 motor running at full song killed [2] receivers.We put that SAW boat on the beach... twice [at 75+ mph] before figuring out that the vibration being transfered through the boat from that solid motor mount was killing the receivers.There was so little room in the radio box we couldn't pad the receiver so David Hall retrofitted the boat with this motor mount system and shazaam no more radio receiver problems.

 

[BB Mods's]

$56 in wood to build this boat, You cant ask for a better deal than that!

 

[TCHedOff]

Hi Rod! I could call you and ask about this, but thought it would be more useful to post here so everyone can read your reply.

I'm working on the rear ski tonight and noticed your plans dont mention or suggest a width for the bottom running surface of the ski or the width of the sides of the ski. Small thing, but others will get to this point and go hmmmm.... 1/2"? 3/4"? 1"???

Let us know when you have time.

 

[warlokboats]

it looks to measure 1" over all width.

 

[Geraghty]

it looks to measure 1" over all width.

1" is correct....

 

[TCHedOff]

it looks to measure 1" over all width.

1" is correct....

Thanks!! I didnt bother to print out your new plans (tho I have them saved) because I have the one from last yr, and I'm about done w/my build 'cept for the ski, servo's & paint.

 

[Zach Davis]

it looks to measure 1" over all width.

1" is correct....

Thanks!! I didnt bother to print out your new plans (tho I have them saved) because I have the one from last yr, and I'm about done w/my build 'cept for the ski, servo's & paint.

Please share some photo's with us.

Thanks,

Zach

 

[TCHedOff]

it looks to measure 1" over all width.

1" is correct....

Thanks!! I didnt bother to print out your new plans (tho I have them saved) because I have the one from last yr, and I'm about done w/my build 'cept for the ski, servo's & paint.

Please share some photo's with us.

Thanks,

Zach

Hi Zach!

Will do AFTER it's painted - give me a week or two (I actually have 2 of these boats under construction). The first was a FireFighter that sent to me by Martin Truex and modified to Rod's instructions. I used an alchohol based stain (beautiful ruby color ) because I'm no painter. Unfortunately, there was two small spots where glue that had soaked into wood on the outside of the tub, so the stain didnt take at those spots. I wasnt satisfied, so off came the epoxy and the stain (and it looks like crap right now) and I'm taking it to a painter to have painted.

The other tub is "better" in that it is all tongue & groove construction instead of butt joints (but otherwise identical) - AND this time I WAS able to use the red stain successfully.

todd

 

[TomMoorehouse]

it looks to measure 1" over all width.

1" is correct....

Thanks!! I didnt bother to print out your new plans (tho I have them saved) because I have the one from last yr, and I'm about done w/my build 'cept for the ski, servo's & paint.

Please share some photo's with us.

Thanks,

Zach

Hi Zach!

Will do AFTER it's painted - give me a week or two (I actually have 2 of these boats under construction). The first was a FireFighter that sent to me by Martin Truex and modified to Rod's instructions. I used an alchohol based stain (beautiful ruby color ) because I'm no painter. Unfortunately, there was two small spots where glue that had soaked into wood on the outside of the tub, so the stain didnt take at those spots. I wasnt satisfied, so off came the epoxy and the stain (and it looks like crap right now) and I'm taking it to a painter to have painted.

The other tub is "better" in that it is all tongue & groove construction instead of butt joints (but otherwise identical) - AND this time I WAS able to use the red stain successfully.

todd

Tongue and groove... That was hard work I bet! I can't wait to see it!

Exactly oppisite of what I'm doing. I'm still trying to make my no paint/no wood boat for easy building!

 

[TomMoorehouse]

Are the sponson insides/outsides/lefts/rights all the same shape? I only printed the one main parts page and want to make sure I don't need the other templates.

 

[TCHedOff]

Are the sponson insides/outsides/lefts/rights all the same shape? I only printed the one main parts page and want to make sure I don't need the other templates.

TOM: Left and right sponsons are identical. I made a couple sets - one exact to Rod's specs, the other slightly narrower - just to test the differences.

As for the tongue & groove boat. Instead of trying to router or dado out things, I opted to use a combination of 1/16 ply and 1/32 ply. How I did it was to make a template from the plans out of Mylar (thanks Rod!! ) . I used doublesided tape to laminate 2 pieces of 1/32 ply and 2 pieces of 1/16 ply together into one solid piece. Then I applied masking tape over one whole side (to draw on - hate drawing on the wood itself).... and used the template to draw out the tub onto the wood. Cut on the band saw, and then sanded/filed everything down to final shape. Pull off the masking tape, seperate the 4 different pieces of ply, and TA DA!!! - 4 identical tub pieces.

I then opted to use the 2- 1/32 tub pieces for the outer surface of the tub; The 2-1/16 pieces I chose for the inner sides of the tub. I re-doubled taped the 1/16 pieces together, masking taped one whole side again and marked off where the transom would be, the baitbox bulkhead, the center bulkhead, and the nose bulkhead, and the top (I planned 1/16 for the bulkheads and 3/32 thickness for the transom and 1/16 for the top). Cut these at the marked lines on the bandsaw - take off masking tape and seperate, and TA DA!! 2- identical radio box pieces and 2 engine bay area pieces. Then I cut short 1/16 shims to align the 1/16 pieces onto the 1/32 full length tub pieces. Woodglued and clamped together each side (using a razor blade to remove all excess glue squeezed out by the clamps - do this before the glue dries!) TA DA... two identical tub sides all tongue & groove. Cut the bulkheads etc and glue into the grooves (Use a jig to get the tubes side truly vertical and parallel). Cut & glue on the bottom (I used a jointer to get the edges of the bottom sharp and true first). Lastly cut & fit on the top into the groove.

I told Rod I built the 2nd this way and he said "GREAT - that thing will be as strong as a tank!" Given that comment, I expect to build some more sponsons this way (as the others are butt joints). Lastly, I recommend a jig to build the sponsons too (ask me why :lol: ). My sponsons are hollow - Rod said no need for wood over foam - with 3 vertical formers inside made of 1/16 ply. All of the sponsons were made from 1/16 ply. Next time I'll use 2 pieces of 1/32 and use the same technique as the tub. Hope this helps those looking for ideas on assembly.

PS I DONT put this out there as if I'm any sort of master boat builder - I'm NOT!! I just thought I'd help Rod by sharing some of what he has told me in the countless conversations we've had about this boat. Again thanks Rod - YOU DA MAN!!!

 

[TomMoorehouse]

Wow... That took some time! I was thinking about not going the wof route with my sponsons but if they fill with water it might sink! G10 and PVC doesn't float very well.

 

[TomMoorehouse]

About an hour in the shop and this is what you get. Maybe I should call this the McMasterr JAP boat. All my construction material is from Mcmaster Carr. So far it is just 1/8" pvc and 1/4" fiberglass rod. I have the .015 G10 for the rest. I think I can cut it with scissors, should be easy! I think I will put an aquacraft .18 I have in it.

 

[TCHedOff]

This may be a good, CHEAP source for printing out the JAP plans:

http://www.rcuniverse.com/market/item.cfm?itemId=499898

10 bucks for 30 sq ft. Ad says:

That's 10 linear feet of plans on 36" paper for $9.99.

Don't tile print & tape dozens of little sheets when I can print you a professional quality plan at minimal cost. I can also enlarge or reduce any drawing to the size and scale model you desire at no charge. Print jobs over 30sq/ft will have the additional area billed at my normal rate of 40¢ per sq/ft. Print jobs less than 30 sq/ft are billed at the 33¢ sq/ft ad discount rate for actual square footage of paper used.

(Thats the advertiser's words - not mine BTW! )

 

[J Solinger]

I hate taping sheets together. It works but working with a single sheet makes life better.

I finaly got a photo of the rudder assembly. Super simple.

 

[TCHedOff]

An observation to share....

I bought a Hughey .150 to 3/16 flexshaft & propshaft preassembled (which I promptly proceed to cut too short :huh: :lol: ). If you chose to use Glenn Quarles Fuller's Fast Electric mini strut (not the one that kicks back).... you'll find the propshaft is quite long and even w/ the proper gapping between propshaft & flextube inside the strut and between the end of the strut and the drive dog, you'll still find need something to get the prop nut to push the prop up againt the drive dog - and Glenn suggested a piece of fuel tubing. Great solution! Thanks Glenn!

Meanwhile ordered another .150 to 3/16 flexshaft to propshaft.... this time from FunRCBoats. The propshaft from them is MUCH shorter than the Hughey one. Either can be made to work, but they ARE different.

 

[TERMINATOR]

An observation to share....
I bought a Hughey .150 to 3/16 flexshaft & propshaft preassembled (which I promptly proceed to cut too short :huh: :lol: ). If you chose to use Glenn Quarles Fuller's Fast Electric mini strut (not the one that kicks back).... you'll find the propshaft is quite long and even w/ the proper gapping between propshaft & flextube inside the strut and between the end of the strut and the drive dog, you'll still find need something to get the prop nut to push the prop up againt the drive dog - and Glenn suggested a piece of fuel tubing. Great solution! Thanks Glenn!

Meanwhile ordered another .150 to 3/16 flexshaft to propshaft.... this time from FunRCBoats. The propshaft from them is MUCH shorter than the Hughey one. Either can be made to work, but they ARE different.

tood why are you not using .130 ..it is much stronger than the .150 cable. i know it sounds funny but i have been told that alot by guys and proven it in my 12 boat. and you can make your own .. buy the octura setup and you can get it with the 3/16 propshaft all the other goodies all for around 11.00 and it is easy to make one..i bet larry conrad could help you out there..

terry

 

[TCHedOff]

An observation to share....
I bought a Hughey .150 to 3/16 flexshaft & propshaft preassembled (which I promptly proceed to cut too short :huh: :lol: ). If you chose to use Glenn Quarles Fuller's Fast Electric mini strut (not the one that kicks back).... you'll find the propshaft is quite long and even w/ the proper gapping between propshaft & flextube inside the strut and between the end of the strut and the drive dog, you'll still find need something to get the prop nut to push the prop up againt the drive dog - and Glenn suggested a piece of fuel tubing. Great solution! Thanks Glenn!

Meanwhile ordered another .150 to 3/16 flexshaft to propshaft.... this time from FunRCBoats. The propshaft from them is MUCH shorter than the Hughey one. Either can be made to work, but they ARE different.

tood why are you not using .130 ..it is much stronger than the .150 cable. i know it sounds funny but i have been told that alot by guys and proven it in my 12 boat. and you can make your own .. buy the octura setup and you can get it with the 3/16 propshaft all the other goodies all for around 11.00 and it is easy to make one..i bet larry conrad could help you out there..

terry

Ahhhhhhhhh.... 'cause that was what Rod G set me up with when I sent him my motor.... When I first got my engine, and Rod looked it over, he mentioned something about the flywheel needing some minor changing and that he had machined a custom collet or something.... and .150 to 3/16" was how it came back. BTW I bought one of Mark Leyde/Hydroracer's cowls. Boat should be painted in a few days and then I'll post a pic/time to break 'er in (maybe I SHOULDNT use the word "break" :lol: )

 

[TomMoorehouse]

Ok, well I got in a hurry and messed up..... I always do when I rush things. ended up building my tub crooked... And the worst part is I don't have enough material to make more tub sides so I need to buy more!

Since the tub was crooked I decided to try some destructive testing with my building method/materials, I'm using 1/8 expanded pvc and .015 G10. I had just tubsides and bulkheads with only the bottom attached. all glued with CA. I was able to twist the tub almost 90 degrees from tip to transom before anything would break. One bulkhead joint failed. That's pretty bullet proof in my book.

Good news. I found a different place to buy the expanded foam PVC and got some in RED! should be cool!

 

[Raymond Bonenfant]

Rod,

Thanks for creating this thread. I had a slew of questions to ask this morning and was going to post them to the “.12 JAP boat plans now available” thread but when I went looking for it I found this thread and…. viola, here am. Just think, I didn’t even have to reveal my weaknesses by asking ‘all’ of my rooky questions I did say ‘all’ didn’t I? I hope so because I do have a few questions left. :huh:

1) Is it safe to assume that the sponson attachment rods are glued into place?

2) Should the inside of the sponsons have balsa blocks glued in place to support the rods or will the sponson side panels carry the entire load?

3) What about safety floatation? Is that something that needs to be worked in around all the running gear?

Thanks everyone for sharing your lessons learned. I will reciprocate when I get that far. I have to finish my Dumas Miss Unlimited build before I can start on this build. How about more build progression and completed pics?

Rod, I could not agree with you more when you say that thing about ‘building them is more fun than buying them’. Its a lot of fun putting RC and woodworking together into the same hobby.

Raymond.