Barrel Back….

[Bob Abell 2Participant @bobabell2]

Hello Paul

 

Thanks for the special photo……..quite a chunky motor!

 

I`ve been using HOBBY`S chain………see photo…………….and you could fit double sprockets and chain if necessary………….would look the bizz then!

 

I would still think about omitting the stub shaft………………put the sprockets on the prop shafts…………..and split the chain?

 

Just another free of charge super suggestion……………….Bob

 

[Paul TParticipant @pault84577]

Thanks Bob

 

I will have a look at the Hobby’s site.

 

Paul

[Phil Winks 1Participant @philwinks1]

That really is a chunky piece of motor Paul! glad to see your at least well enough to do a bit of fiddling mate. One point I have with this style of drive from a single motor to twin props is “no counter rotating props”. does this not cause a largish element of (for want of a better expression) tourque steer requiring large amounts of Rudder trim and so reducing your left turning ability or do you put trim tabs (I guess like fixed rudders) on to allow the rudder to be central when going straight? We do have a similar prob with twin engined aircraft but that has more to do with gyroscopic precession not something that would effect the relitively small props of a boat I guess. On a plus note the finish on my barrelbacks latest coat of varnish has me thinking that I’m very close to the top of that particular hill

[Paul TParticipant @pault84577]

Phil

 

I have built twin engined models and have fitted both contra and same rotation props and the only model that showed any kind of “crabbing” when fitted with same rotation props was my Trent.

 

The Trent is by no means a heavyweight and is fitted with two geared 650s so it is capable of quite a turn of speed, It only “crabbed” at speed when the hull was high in the water so I fitted contra rotating props which solved the problem.

 

This is my first single engine / twin prop build so I am not sure how it will respond on the water but I don’t think that it will go fast enough to cause me any problems….the engine might look meaty but it has to shove a lot of boat along.

 

Still it will be fun finding out when I finally get to sail it at Runcorn and as long as it dosen’t go round in decreasing ovals I shall be happy.

 

Paul

[Phil Winks 1Participant @philwinks1]

Me too Paul I originally started this project to give thegrandkids something really different to try when they visit in august. along the way a couple of unexpected things have happened. 1 the model boating bug has bitten and 2 met some really nice people both at the tvmbc and on here who have/are making this build so much more fun. so a follow up model is a dead cert now

[Paul TParticipant @pault84577]

In this world of self serving, grabbing & greedy gossiping back stabbers I have always found that model boaters are the nicest of people, generous, friendly and above all honest.
Being part of a loving family has given me a much needed anchor in this crazy fast paced world and being part of the modelling community has given me the perspective and wisdom not to take myself to seriously and not to get sucked into the rat race.

 

The secret to a happy life………build a model boat.

 

Being such a nice sunny morning I took the camera and tried to capture the depth of finish on the barrel backs deck.

 

 

>

The reflection is a street lamp just outside my fence….this finish is the result of 40 coats of varnish, each one has been rubbed down with 400 / 1200 and 2000 grit wet & dry paper to get to this stage.

Paul >

[ashley needhamParticipant @ashleyneedham69188]

Paul, Outstanding, simply outstanding and the sort of finish one expects on a boat of this sort. A mirror smooth glass surface. Excellent. I am having to have a sit down now to fully appreciate the beauty of that deck . Yes i know the boat will be slow and after 10 mins of running that puny chain will give way but you can`t have it all eh ???      Ashley

 

 Words fail me for that surface, they really do. To rub a finger over that would I think bring a tear to me eye.

[Paul TParticipant @pault84577]

Thanks Ashley

 

My grandfather showed me how to work with and appreciate wood and I always try to keep up the standards that he instilled in me.

I am also very fond of well presented varnished boats……if a job’s worth doing etc.

 

I have been pondering the drive chain and this afternoon gave it a strength test by hanging a 56lb weight from a 1ft length…….it held all afternoon but did stretch a bit.

A bigger problem is that I did some power to weight calcs for the engine both on a single and twin prop setup and the extra thrust from 2 props isn’t worth bothering with so I might revert back to a single.

 

Thanks again for the kind comments about the varnish.

 

Paul

[Phil Winks 1Participant @philwinks1]

That just proves what a true craftsman you are Paul far superior to the finish on mine and a real challenge for me to do better on my next project which is looking more and more like waiting till autumn to be started

[Paul TParticipant @pault84577]

There really is no secret to a reasonable paint or varnish finish you just have to take the time to prepare the surface properly and use a lot of elbow grease.

Of course you have to be patient whilst the paint or varnish dries before starting to rub down again and have the discipline to rub down each coat three times with increasingly finer grades of paper.

You also have to buy the best materials that you can afford.

It might sound like an old fashioned way of doing things but it works for me.

Paul

[ashley needhamParticipant @ashleyneedham69188]

Paul, on the chain thing. I dont doubt that it is strong enough, it was the wear rate that would worry me, unless it was lioberally smothered in grease and then you would need a protector to stop it being flung everywhere?   Ashley

[Paul TParticipant @pault84577]

Morning Ashley.

I had intended to build a gearbox to contain any lubricant but I am having 2nd, 3rd and 4th thoughts about the whole power train so at the moment its back to the drawing board.

 

Paul

[Paul TParticipant @pault84577]

Ashley

 

After much thought ( 30 seconds) I have decided that I will not be putting any dolls,action men or any other kind of little people  in the boat.

I asked Janes opinion and she said “If you put an action man in that boat I will sink it as I can’t think of anything more naff“

So that sums it up.

 

Paul

 

 

[Bob Abell 2Participant @bobabell2]

Hello Paul

Don`t be so hasty!………………An open cockpit must have a driver?…………..how about a comical monkey?

 

There`s a chap in the Bury club, building a chunky paddler and he`s got a driver………..smoking a cigarette!………..that actually puffs!…………….No doubt he`ll be bringing it to Birchwood again…………..remember the brass engined paddler, last year?

 

Just passing through……………….Bob

 

Club regatta tomorrow at Etherow, taking…….GE and JDAW………….Weather permitting of course!

[Paul TParticipant @pault84577]

Morning Bob

 

Whilst the jury might still be out on this matter the judge has made a binding decision that covers all kinds of small life forms from chaps with cigarettes to elephants with big floppy ears.

 

Don’t know what the weather is like at your end but its windy with rain here and the forecast for the rest of the weekend is not good.

I hope that it doesn’t stop the regatta as I am looking forward to lots of photos.

 

Paul

[Bob Abell 2Participant @bobabell2]

Mornin` Paul

 

As I`ve just told Duckie, history is repeating itself……………..D-Day an` all that………..Well not quite!

 

Looks a bad day all round from this end and the Met boys too

 

We`re all ready and the car`s packed, but from the forecast……………it ain`t gonna let up!

 

We were in Wales again yesterday…………….the rain was absolutely ghastly…………..that`s the fourth consecutive trip to Wales, spoilt by the weather, in the last few weeks

 

Here`s an amusing anecdote…………….The Optimist built the aeroplane and the Pessimist built the parachute!…………….GBShaw

 

Bob

[Paul TParticipant @pault84577]

Bob

 

Your car is packed and you are ready to go………but the weather????

 

Doe’s this make you a builder of aeroplanes or parachutes?

 

Optimist, Pessimist

 

 

or Realist…………..

 

 

 

Paul

Edited By The Fat Controller on 06/06/2009 07:53:23

[Bob Abell 2Participant @bobabell2]

The show must go on!………………..say`s Duckie

 

We`ve got an indoor display organised, with a few gazebo`s outside….for the poor little Blind Dogs………………umbrella`s recommended………….and Sar` Westers!……and a lifeboat……………….just the weather for Ducks!

 

Bob

[Phil Winks 1Participant @philwinks1]

Don’t know about Bob Paul but I’m an eternal builder of aeroplanes mate  both literally and figuratively. We were at breen cove thurs (just over the water from cardiff) where i suffered structural wing failure on one of my own design aircraft (tough sport that) weather was superb and a real shame I’ve not got the props for my Barrelback yet. the incoming tide was almost mill pond like and would’ve been a real good time to try her out with lots of space still our little Jack russel enjoyed his swim wonder if I could train him as a boat rescue dog Good luck with the reggatta Bob

Edited By Phil Winks 1 on 06/06/2009 15:41:09

[Bob Abell 2Participant @bobabell2]

Paul and Phil

 

Seen at the regatta today, in between rain showers…………..Heavy speedboat, plywood construction, powered by a Graupner 900 series motor, running at 7000 rpm, powered by 30 volts, and water cooling

 

Just thought this may be useful info for your Barrel Backs

 

Not a bad day today….good turn out…..and the Blind Dogs came indoors

 

Bob

[Paul TParticipant @pault84577]

Looks like a Sea Commander thats had a face lift

[Phil Winks 1Participant @philwinks1]

Thanks for that bob looks pretty convincing

[Paul TParticipant @pault84577]

An update on the motor situation.

 

 

After a prolonged workbench test run yesterday I have made changes to the motor setup.

I have ditched the gears and twin drive and now decided on a single direct drive with the motor running at 24v.

 

The motor is very powerful but slow when running at 12v so an increase in voltage will give me the extra “oomph” without having to worry about the drive chain failing.

However the can gets quite warm so I will fit a pump to the cooling system to maintain a constant water flow.

 

I am planning to make the shaft today, health and grandson permitting.

 

Paul

 

nb: I will certainly be fitting this type of motor in the TID (when I get around to it) as it has amazing grunt and has no loss of power or revs even when under huge load. 

 

Edited By The Fat Controller on 07/06/2009 07:44:34

[ashley needhamParticipant @ashleyneedham69188]

Paul. Simplest is best, I don’t think you will have cause to regret not fitting all those gears and things, provided you get the motor/prop combination right. Ashley

[Bob Abell 2Participant @bobabell2]

If you`ve got plenty of grunt at lowish revs……………….then a coarse prop would make up for it.

 

The boat I posted yesterday, had water jackets soldered to the motor casing and also a syphon type pipe which automatically emptied any surplus water from inside the hull

 

Just passing…………………Bob

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