Birthday boat

[Bob Abell 2Participant @bobabell2]

Amy J

Have you tried a floatation test yet, to check the balance?

Would like to see a general view of your model, please…..On a stand?

Bob

[Amy jane SeptemberParticipant @amyjaneseptember49770]

Hello Bob.

The engine is over the centre of bouyency, so the fore and aft trim will be fine. She will need a couple of pounds of ballest, athwartships, to offset the weight of the cylinder. I shall get on to the craddle, and get a couple of decent photos up for you.

Amy jane

[Amy jane SeptemberParticipant @amyjaneseptember49770]

Hello again.

Well, Bob as promised here are a couple of general view shots. The cradle is made, though the glue wasn't dry in time. So, due to the shortage of palm trees, I took the boat down to the jetty…

The rudder and prop are in. Following Ashley's advice, the prop is made up from a bit of sheet ali, so it can be easily adjusted until I'm happy with it, then something a bit flasher made. (or not) I was researching props and was suprised at how little pitch the had, only 3 or 4". Until I discovered that they were being coupled to 26cc engines that were producing 5hp! The revs must be horrendus! The prop on this is 4×7" for a much more civilized 5,000 rpm.

The business end is looking, well, business like!

The radio gear is all in, been busy soldering extension leads…

[LARRY WHETTONParticipant @larrywhetton68737]

good morning Amy Jane ……………..

Loving the rustic look ……………………….your old mate Larry…………..

[Bob Abell 2Participant @bobabell2]

That's looking really nice and business like, Amy J

Are you going to paint it or varnish it?…….Varnish?

How does the engine run?

Keep up the good work

Bob

[Amy jane SeptemberParticipant @amyjaneseptember49770]

Hi there Larry. Great to have you back on deck! Take good care of yourself m'dear.

Thanks Bob. She'll be mostly painted, but there will be plenty of varnished kauri trim. I haven't run the engine since the testing for the clutch, but these little engines are sweet runners, so not anticipating any problems.

Exhuast is in

rudder set up

The rudder stock is left over prop shaft. The bottom has a steel cross piece welded in, and the ply blade glued either side. The top is squared off and the ali tiller slipped over and pined through

throttle hooked up.

All systems have been tested, and everything is working properly. Next step is to install the petrol tank and shield the radio from electrical interference, then it's off for a test run….

[shipwrightParticipant @shipwright]

Hello Amy,

I have a couple of questions about your prop :

a. How did you ensure that it is dynamically balanced – if that prop is not properly balanced, at 5000 rpm it could vibrate violently and even shear the propshaft.

b. What grade of aluminium did you use ? My experience with sheet aluminium that I have used is that it is quite soft and when you bend it fracture lines can appear ?

Best wishes.

Ian

[Amy jane SeptemberParticipant @amyjaneseptember49770]

Hello Ian.

The aluminium is from a office partition frame, and is quite soft, but seems quite robust. Lynn has been making model aeroplane propellors out of this stuff for a year or two, with good results. (these are 9 or more inch props, turning at 15,000 plus) The prop was properly balanced on Lynn's prop balancer.

Thanks for the interest and good wishes, like everything we do, time will tell…..

[Amy jane SeptemberParticipant @amyjaneseptember49770]

Hello all.

Phew, that was a learning experience! Neither Lynn or I knew the first thing about shielding the engine, to stop interferance with the radio, other than that it had to be done. So we both decided to research it independently, then compare notes. There was a lot of different opinions out there, and the debate on some of the forums got quite heated! placement of radio servos, use of ferrite rings in servo leads, not using metal push rods etc etc. We came to the conclusion in the end that it all came down to doing a proper job of shielding the high tension side of the ignition. Properly done, nothing else much mattered, not properly done, none of the other stuff would be of much help. It also seems that 2.4 meg is much less affected (I'm useing 40meg). All those of you that have done it all before, please feel free to comment, the more information the better. Rightly or wrongly, this is how I went about, and it seems to work. The servos are rock steady at any engine speed.

The first step was to shied the HT lead and spark plug. This was done by removing the pug cap and sliding several layers of copper mesh over the lead.

The mesh was stripped off a length of co-ax TV aerial cable, of which I have plenty.

The next step was to make a new plug cap. It would seem important that the plug cap covers the plug right down to the cylinder head, and that the copper screening covers the cap and earths to the engine. I put the original plug cap back on, put the plug in, then wound the cap and plug with a strip of stocking, right down to the thread. This was silicone rubber coated and more stocking wound on etc, untill a sustantual cap was built up. The copper screening was then wound around the cap and tucked in side it, so it would earth against the hex on the spark plug. A bit of solder was used to hold the winds of mesh together, then the whole thing was wound with tape. The coil was covered with ali foil, as was the rx.

So all is ready for a range test, and a run on the water, but the weather is lousy!

Aj

[Mark TommyParticipant @marktommy83416]

Good luck with the test run – Looking forward to seeing the pictures

[ashley needhamParticipant @ashleyneedham69188]

Amy. There is a lot of rubbish talked about interference..other forums?? there is only one you need.

There is no right or wrong. I think you have taken the sensible course of action here, supressing the ignition system. I think you seem to have mad e a thorough job of it and indeed the proof is in the eating of the pudding or something and indeed you dont appear to have any issues so must have done it right.

Paul T is the man for supressing i/c engines, if not the masses.

Lousey weather?? are you having us on..it is always sunny downunder surely??

Ashley

[ashley needhamParticipant @ashleyneedham69188]

Amy, just looked at the rest of your photos..noticed the rudder is wood, and not best office furniture ally/car body steel/gold forged from nuggets found in your stream??? any particular reason other than its easy to do?? 

I am going to say that the skeg/propshaft support looks a bit fat to me.I can hear the sharp intakes of breath at the extreme cheek being displayed here is raising any sort of issue regarding this fine build but is just looks a bit, well…FAT to me and draggy…so I  am saying so, or have I read but forgotten that the Adze has yet to come out on the nether regions of this craft.

Its difficult this, one never knows how someone is going to take comments on a build, and by this I mean of the critical variety..not just criticism per se, but constructive criticism. This is a forum after all and when people put, say, pictures of their first build on the site, and one looks at it and thinks….hmmm…could do better here and there..no one says so, and all the posts are usually of the "well done for your first build" kind, and so the first time builder never knows that improvements could be made in some areas, or if they do they do not indicate that they know of the failings and so on. It`s just tips and hints really that need passing on, but I know some people just get the hump if you dare to suggest anything could be made a bit better. Should we be passing comment? or only positive comment to the exclusion of all else???

I hope you dont mind me mentioning the fat bit, and it not a criticism but merely an observation. You obviously know what you are doing and no doubt are aware of this anyway and are going to either slim it down or indeed leave it alone as you know it wont make much difference. Extra meat on this area may indeed be called upon due to the herculean forces due to be exerted by the 26/35/40/500cc engine. BUT it is the sort of thing perhaps other people would not notice and it could be something that needs to be pointed out.

Ashley

Edited By ashley needham on 18/04/2014 18:10:53

Edited By ashley needham on 18/04/2014 18:48:56

[Amy jane SeptemberParticipant @amyjaneseptember49770]

Hello Ashley, good to see your grinning face!

Should we be passing comment? yes yes yes! I for one am happy for people to say what they like about my build ,either I agree with it or not, and take no offense. Of course I might not agree with the comments, and even threaten to poke some ones eye out (sorry Bob) but it's all meant tounge in cheek, no offense. The forum is all about sharing information, honest and respectful evaluation of others work, even if it is not our particular cup of tea. If we can see someone going wrong we are obliged to say so! I have in the past expressed frustration at not getting answers to questions. (I know that Paul has done all this before, and I am some what puzzled at his lack of input?) I enjoy getting feed back, and it adds greatly to the enjoyment of the build!

As for the "fat bit", no of course I don't mind, I even agree with you! The explaination is simple. The only tube I had at the time was 3/4" and I have planed the skeg down has much as I dare!

The wood on the rudder is to fair in the 3/8" rudder stock.

As an aside, to your comment on gold nuggets found in the stream….. The stream is actually on Lynn's property' Her place was a one time railway yard, and is a gold mine of resources. If she wants some thing she just goes digging for it! Coal in one part, gravel from another, When she dug the power cable trench for the granny flat, she unearthed a large quanity of brass sheet and ali extrusion!

Auckland's weather is very changeable we have just had gale force winds and rain, but is on the mend now.

Thanks for the good wishes Mark, I shall get her on the water at the first oppertunity.

Amy jane

[Bob Abell 2Participant @bobabell2]

Hello Amy J

Have you had a floatation test yet?…..I'm referring to the boat of course!

Almost there and the moment of truth

All the best

Bob

[Amy jane SeptemberParticipant @amyjaneseptember49770]

Good Morning Bob.

No, not yet. The weather is not too bad, but I left the boat at work, so will have to wait until next week now.

Thanks

Aj

[Paul TParticipant @pault84577]

Hello Amy

I am enjoying watching your build which has been both interesting and instructive, please don't take my lack of comment as a lack of interest.

You are a very rare item, not only are you the only other petrol head on the forum but you are actually building a 'proper' boat so I wanted to see how you overcame problems without being influenced by my comments (which aren't always correct)

For example your solution to the suppressing problem follows a different method to mine as I prefer to shield the RX from the engine rather than suppress as you have. Your method has made me think about changing my approach.

I am now eagerly awaiting the launch to see how your boat responds in the water.

All the best

Paul

[Bob Abell 2Participant @bobabell2]

Amy J

I know Paul is loving this thread!

He`s our only IC man and is very impressed with you unusual lady skills!……As we all are!

Bob

[Amy jane SeptemberParticipant @amyjaneseptember49770]

Thanks Paul and Bob.

Paul. I was begining to wonder if I had done some thing to offend you, silly me. I'm glad you're enjoying the build. I would be interested in the way you would have gone about the interference shielding, like I say, the more knowledge the better, (surely that's what a forum's all about?) The information was quite hard to come by, It would seem most modlers just buy a "model engine" set up and ready to go, and don't really understand what's going on. I eventually found a Spanish forum that provided the info needed, relying on the computers translating software. Things got quite comical!

I think if any info posted on this thread would make someone else's life much easier, Say Jeff Sinclar for example, if he does his lawnmower powered masterpiece, (I hope he does….) then I would be very happy about that!

I'm some what nervous about the test run, but even if it all turns to custard, I'll let you know….

Thanks Again

Aj

[Paul TParticipant @pault84577]

Amy J

We all get nervous before the first test run……………..even more so when the model weighs 20kg and travels at 40mph.

Your will be fine just choose a stretch of water with sloping muddy banks.

Paul

[Bob Abell 2Participant @bobabell2]

Also, Amy…….The prop will be running at time of launch!

You could do with a chainsaw apron!

Bob

[Andy CParticipant @andyc56856]

Amy, I am pretty sure both you and Lynn will be absolutely fine on your maiden voyage. Nerves aside, please take loads of pics as we are waiting with baited breath as to how she will perform. I am also pretty sure the Birthday Boy will love her.

Andy

[Amy jane SeptemberParticipant @amyjaneseptember49770]

Hello again.

Thanks for the good wishes all!

As it turned out, no need for nerves at all!

Here we go…..

Just a shot in case I never see her again…

Start her up, (stared second pull), push her off, engine at idle, take a deep breath and engage the clutch…..

…..and open the throttle……

Yipeeeee!!!!!

Sorry the photos aren't better, I was on my own, so it was a bit of a juggling act, camera in one hand, transmitter in the other! The boat handled flawlessly, banking nicely in the turns, and running straight in between.

The clutch worked well, engaging and disengaging happliy. Cutting the throttle automatically disengages the clutch due to prop drag, nice when coming back into the wharf. She had a good run, got her air born, jumping her own wake. Gets about 20 minutes on a tank, which is plenty.

She sounds good too, not too loud, and everything done with a deep rumble suggestive of real machinery!

I'm guessing a scale speed of 20-25 knots (that is the speed she would be doing if full size), so I may play with the prop a little, to see if I can get a bit more out off her. That, a bit more rudder throw, and some trimming ballest forward, is about all the modifications I think she needs.

On the right track I think….. I'm happy

Aj

[Mark TommyParticipant @marktommy83416]

Nice one That looks fantastic!

[Paul TParticipant @pault84577]

Amy

You are now a member of the very exclusive petrol head club and you will now understand what it means when I say that there is nothing to beat the euphoric mix of 2stroke and panic.

Congratulations on a very successful build and first sail.

Paul

[ashley needhamParticipant @ashleyneedham69188]

Amy J. Fantastic. I knew it would work.

Whats the next project???

Ashley

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