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Author Topic: Colin Archer  (Read 19363 times)

labougie

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Colin Archer
« on: September 09, 2009, 07:23:59 pm »

I've recently made a start on my first r/c model boat - a Colin Archer.  The big Billings (414) was going to be too large to transport (and I also fancied plank and frame construction) so I had the idea of acquiring the small Billings kit (606), taking the lines off and blowing them up 200% to give me 72cm LOA.  'Longshanks' kindly provided me with the David Petts article describing his adaptation of the 606 to an r/c sailing model, which has been a great help.

The stage I'm at atm is the bulkheads (6mm ply) have been cut down to ribs and the internal keel (4mm ply) cut down to allow space for the gubbins.  I've got the ribs glued in to the keel and we're currently looking like this:



The plot is to plank it in spruce and use a two-pack clear finish (I've used Rustins Plastic Coating before now in a different application and it seems to be pretty tough so I'll probably go with that).  Petts fibreglassed the inside of the hull and I figure that would make sense - I've seen some woven 120gsm tape at 75mm wide, which would fit nicely into the gaps between ribs (60mm) leaving a little on each side to go up the ribs.  Does 120gsm sound about right?  Any input much appreciated.



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longshanks

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Re: Colin Archer
« Reply #1 on: September 09, 2009, 10:09:56 pm »

Hi
I think you said you were using 3 x 10mm planks which should be quite firm. I would be tempted to use tissue instead of 120 tape unless you have to do a lot of sanding to fair the lines.

Save weight, more weight low down - better sailing  :-))

longshanks
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labougie

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Re: Colin Archer
« Reply #2 on: September 10, 2009, 04:05:29 pm »

Idly thinking about planking while waiting for glue, timber etc to arrive.  A few questions:

1/  I'm assuming the garboard strake ought to be a longish plank, starting and ending on a frame station.  As a planking philosophy on a double-ender, should one subtract from the amidships width of each plank as one goes fore and aft, or keep them parallel and end up with shorter planks coming towards the garboard?

2/  I could make my life much easier by using 2mm planking, not 3mm.  Would this be strong enough (on 65mm frame stations) with glass reinforcement inside?

3/  Should the planks meeting the stem and stern posts be rebated into the posts, or faired away to nothing (from the inside) as they meet?

There are going to be many questions........ 

Think I'll draw up a king plank tonight - curved deck planking would be nice.  I've also half a mind to cut away the (straight) deck beams after I've planked and replace them with cambered ones.  The beam amidships is 250mm - how does a 5mm rise to the centre line sound?

I've only just noticed that this posting is in the 'Masterclass' section which is not exactly apposite - if the mods would like it somewhere else, please move it.  Thanks
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tigertiger

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Re: Colin Archer
« Reply #3 on: September 11, 2009, 01:42:13 am »

Hi Labougie

Are you talking about deck and hull planking here?

1/ I am not expert, but my garboards run from stem to stern.

2/ Depends on the wood. If using balsa then 3mm would be stronger. If using cedar or other 'normal' timbers, 2mm with FG reinforcement is more than adequate. IMHO.

3/ Rebated. It actually makes the job of planking easier. And it gives you a good straight line of plank ends.

Re: Curved deck planking.
What did the original boat have? Working boats generally had straight planking.

------------------------
Don't worry about placement of this thread.
It is under Yachts and Sail.
Yachts and Sail is a separate board under the heading Dry Dock, along with the Masterclass Board
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labougie

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Re: Colin Archer
« Reply #4 on: September 18, 2009, 04:37:21 pm »

Thanks for the input.  I've just now come home with my spruce so I'll have some planking pics in the next few days.  If I were going to put a motor into her, what size motor and what diameter propshaft?
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labougie

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Re: Colin Archer
« Reply #5 on: September 27, 2009, 03:36:24 pm »

A progress report. I'm having problems trying to get pics up so I've just given the URLs.

I got my spruce in 3" x 36" x 3/32" sheets and cut it down to 10.5mm strips on the bandsaw, cleaned up the edges on my magic little hand operated thicknesser and wound up with plenty of nice clean 9.5mm x 2.3mm planks.



There were several false starts before I found a way to plank her.  I had it in my head that I should start from deck level and run the planks parallel to the deck which simply didn't work.  There were abrupt changes of direction and orientation and the planks just wouldn't sit fair and had to be broken off.  After five tries at it I gave up and decided to let the planks go where they wanted to go, so I started 3 planks down from the deck amidships and let the plank follow the rib shape and rise up towards the deck at stem and stern.

http://i17.photobucket.com/albums/b58/labougie/DSCN3767.jpg

 I’d also found that number 5 rib was almost 2mm proud of the line and was therefore creating a lump (no idea how this happened – I thought was fairly accurate with the cutting and sanding but........).  Things were much smoother after I'd sanded it down.  


This was infinitely better, I'd previously made a classic cock-up - after trial fitting the ribs to the keel I thought it would be a smart move to put an approximate chamfer on bow and stern ribs before they were glued which I did, then promptly glued the port side number 4 rib into the starboard side keel and vice versa.  It's a good job epoxy fills gaps.  Rebating into the stem and stern posts works well.



The fourth plank down was starting to exhibit symptoms of the “I don’t want to go there” syndrome which I’d encountered at the start of things – I had to make up a little jig to get the plank to close up to its neighbour.  Narrower planks from here on down.



I think I’ll get the same fourth plank glued in to the port side then get a few planks in at the bottom. There isn’t a garboard as such – the central ribs come all the way down to the bottom of the keel.


I envisage a shaped spruce board flat across the keel base – probably extending all the way up the stem and stern posts. The more spruce the merrier!  No, I’m not that bothered about the weight – she’s not a racing boat.  It seems to me that I should plank in a straight line from the stern at the bottom of the keel and let the planks fall off the keel as it curves upwards.  I could curve them up, but wouldn’t I just be decreasing the space available at the bow and thereby giving myself more shaped planks to make?

Any input appreciated.  What do people think about a motor and shaft size for this?
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boatmadman

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Re: Colin Archer
« Reply #6 on: September 27, 2009, 04:41:58 pm »

Looking good.

I love the home made thicknesser.

Letting the planks take their own route is a good way of doing it, but you will end up with stealer planks around the sharpest turn of the bilge. You should think about starting planks at the keel as well and work towards the bilge to meet those you are already working with.

When you come to bending the planks you have a couple of options to think about:

1. steam the planks for 10 to 20 mins, offer up to the line you want to plank to, allow to dry thoroughly then remove and refit with glue! Traditional way, but time consuming.

2. soak plank in v hot water for 10 to 20 mins, bend around the curve required, clamp, allow to dry, remove clamps and glue in place - again slow.

3. use a hot air stripper, run the plank in the hot air stream (mind your fingers) backwards and forwards while inducing a curve. Go slowly and dont let the wood scorch - if it does it goes brittle and will probably snap. Have a practise and you will see how quick and effective it is. I used this method on my current build - Bourbon Orca - lots of difficult curves at the bow.

I agree with tigertiger, 2mm is plenty thick enough, you will be surprised how strong it is when glassed up

One thing I noticed - there is only half a hull :o

Ian
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Greggy1964

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Re: Colin Archer
« Reply #7 on: September 27, 2009, 07:25:35 pm »

Hello Labougie

Great job on the boat so far but I noticed your not tapering your planks towards their ends. They should be wide at the midship section and taper towards the bow and stern otherwise your going to end up with odd shaped holes to fill with the final planks.

I wrote an article here that might help

http://www.modelboatmayhem.co.uk/forum/index.php?topic=19469.0

Its a bit involved but I'd be happy to help with advice.
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labougie

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Re: Colin Archer
« Reply #8 on: September 27, 2009, 07:59:38 pm »

Thanks Boatmadman - Plot No 3 above is WAY TO GO!  Works a charm.  Glad you like the thicknesser - I've often thought it might work even better if I substituted a nicely hooked card scraper for the plane blade - just never got around to trying it.

Greggy - Yes, I had tapered ends in mind.  I was going to stop at four planks down, put a few on the keel then start measuring to find out how much I needed to taper them by.  I'll have a look at your article tonight.

As to only half a hull - I thought I might make half a Thames Sailing Barge for the other side and start a new whacky trend in composite models, but I'm having problems with the rig.  If I can't figure it out, I may just have to use the other half of the Colin Archer. %%

Cheers, Chaps.
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tigertiger

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Re: Colin Archer
« Reply #9 on: September 28, 2009, 12:55:15 am »

Very nice job of planking. :-))

And like Boatmadman, I love the thicknesser.
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labougie

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Re: Colin Archer
« Reply #10 on: September 28, 2009, 05:19:12 pm »

Having mentioned it in a previous post, I thought I'd have a crack at putting a scraper blade into the thicknesser instead of the plane blade and it doesn't work nearly as well - I think it may be because the scraper is too flexible.  Planking away like a good-'un - more pics later.
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labougie

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Help with motor/gearbox/shaft/prop for Colin Archer
« Reply #11 on: September 29, 2009, 04:03:18 pm »

I'm new to all this, and building a double-size version of the 606 Billings Colin Archer - http://www.modelboatmayhem.co.uk/forum/index.php?topic=19525.0

Before I get too far I need to decide what sort of auxiliary power to have.  She'll be 720mm LOA x 250mm beam.  Essentially I need to cut a slot for and glue in a propshaft before gluing the two sides together - could anyone advise a suitable shaft diameter and a suitable prop?  What does one do about a thrust bearing?  Given the astronomical rpm figures I've seen for electric motors, I assume a reduction gearbox would be required - is there a thrust bearing in one of those?  Would a 540 motor at 6V be around the mark?  Do I need any cooling?  Any pointers gratefully accepted.
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Martin (Admin)

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Re: Colin Archer
« Reply #12 on: September 29, 2009, 06:17:09 pm »

Photo links sorted.    :-))
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Shipmate60

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Re: Colin Archer
« Reply #13 on: September 29, 2009, 08:38:50 pm »

It depends how fast you want the motor to be able to propell her?

Bob
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longshanks

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Re: Colin Archer
« Reply #14 on: September 29, 2009, 09:34:21 pm »

Hi,

To give you an idea on my pilot cutter (1140 x 300mm) I fitted MFA/Como 919D motor with 2.5:1 reduction. Through standard M4 prop shaft to 30mm dia 3 blade prop. Battery 6volt. Control through 15amp Mtroniks speed controller. Speed/power more than adequate.

Re prop size I guess your boat/rudder being smaller you will have to gauge against your rudder. Dont forget you will need to increase your rudder size by approx 30% - scale boat meets non-scale water!

All available at
http://www.shgmodels.com/acatalog/

longshanks
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labougie

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Re: Colin Archer
« Reply #15 on: September 30, 2009, 12:47:40 am »

It depends how fast you want the motor to be able to propell her?

Bob

Don't need fast - just to be able to get her back it I get stuck somewhere or if the mast folds on me for pushing her too hard!
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Shipmate60

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Re: Colin Archer
« Reply #16 on: September 30, 2009, 09:20:16 am »

If it is just for plodding around a direct drive 385 motor on 7.2 volts and a around a 35 mm prop will provide this.
If you want more power go for a motor that will drive a larger prop a such as a MMB 550.
You wont need any more than 5000 rpm so you could look on the Graupner site for a motor to physically fit.

Bob
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labougie

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Re: Colin Archer
« Reply #17 on: October 01, 2009, 11:21:06 pm »

Thank you, Shipmate60 - Jerome at SHG says the exact same thing so that's a goer.  Got a few planks on the keel -


The gap remaining to be planked is 106mm amidships, 81mm at the stern and 80 at the bow so 11 of my 9.5mm ish planks, thinning down to 7.3mm ish at the ends should do it.

Got to put a new steering rack on my Polo this w/e so more next week.
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labougie

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Re: Colin Archer
« Reply #18 on: October 02, 2009, 11:16:04 pm »

With inspiration from Greggy1964's article on planking, I worked out the size of plank I should be using from here on in.  I measured up the open ribs using paper strips - pretty accurate since it's easy to get a razor blade into bottom of the rib/plank joint.  You also get a graphic of what's going on.



This below has 11 off 9.5mm planks amidships (Station 5) as a given - a couple of mm shy but I'll cut the next lot of planks a little thicker.  When I'm halfway, I'm going to be doing the sums again anyhow to check the percentages still hold.



Is it going to make any difference whether I thin them top or bottom?  Or should I be tapering from each side? Or does it matter?  And if it matters, does it MATTER that it matters?  Exit muttering........
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Greggy1964

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Re: Colin Archer
« Reply #19 on: October 04, 2009, 06:12:09 pm »

Here are some excellent photo's of Vigilance during her 2009 winter maintenance

You can clearly see the run of her planking to give you inspiration.

http://www.vigilanceofbrixham.co.uk/gallery09.shtml   :-))
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labougie

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Re: Colin Archer
« Reply #20 on: October 14, 2009, 10:30:35 pm »

I’ve been asked for a sketch of the thicknesser jig – my sketching ability is almost zero so herewith some pics and info in case anyone else fancies it.  I used beech but any hardwood would do.

It’s simply a base board with two posts screwed and glued into it at an angle of 55-60 degrees. 



My posts are 40mm x 20mm and set 55mm apart.  Once they were in, I glued a piece of 16x55mm (with the bottom cut to the same 55/60 degrees) in between them, the gap at the bottom being the height of the largest piece of timber you’re going to put through it.  I added an extra two of these so I didn’t have to mess about with packing pieces when clamping the blade on.




The blade is just a very sharp plane blade, ground angle outwards so it’s working as a scraper rather than a plane.  Clamp as near to the bottom of the blade as you can consistent with still being to be able to get the work past the other end of the cramp which will be even lower on the ‘in’ side of the jig.


 
Cramp the whole thing to a bench and use a packing piece to guide the wood into the jig so the planks can’t fall sideways on the way through.

What I normally do is clamp it up with the packing piece set for whatever number of planks are going through, put that number into the jig then rest the plane blade on top and clamp it.  This will give almost no cut. Adjustment is by way of a light tap with a hammer on the very top of the plane blade but keep an eye on the squareness at the cut!  Given that the idea is to wind up with all planks the same size, put them ALL through before adjusting the cut.  Don’t try to take too much off – you’ll get a better finish with a light cut and multiple passes.  Don’t expect it to do the job in one pass – I normally go through half a dozen times on each side. 

The bugbear of the design is that you have to push the planks in for quite a way before there’s enough for you to pull out from the other side and thin planks (even in company) don’t like being pushed.  Gently, or they’ll snap on you.

If I gave anybody the idea that it’s quick to use – it’s NOT!  However, if you don’t have access to a thicknesser it’s the only route available.  My planks come off the bandsaw pretty well so all I'm doing is taking off the saw marks - earlier today I was putting 12 teak deck planks through at a time and it didn’t take too long. 



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labougie

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Re: Colin Archer
« Reply #21 on: October 20, 2009, 01:43:30 am »

Still plugging away gently.



A buddy gave me this



which turned into this



and I made a start on this



which I reckon will look rather tasty when completed and finished with Danish Oil.  Onwards and upwards.
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labougie

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Re: Colin Archer
« Reply #22 on: October 23, 2009, 02:24:37 am »

Tapered planks going in-



and more pretty (but VERY slow!) deck-

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tigertiger

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Re: Colin Archer
« Reply #23 on: October 23, 2009, 06:23:42 am »

Your hull planking looks great. I assume you are using 2mm planking on the hull.
On my model it said 3 mm and the planks have not fitted anywhere near as well as yours.
Excellent job. :-))
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derekwarner

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Re: Colin Archer
« Reply #24 on: October 23, 2009, 01:14:53 pm »

labougie........suburb planking  :-))....however a few questions .....I see the hull planking fitted into a rabit [as shown on my markup]  

1) the planking whilst fitted does not appear to be supported by any bronze pins
2) will you flood the immeadiate internal bow area with epoxy resin to secure the construction?
3) tell us about the hull planking material....I could guess but would be wrong

Please keep Mayhem posted with .jpgs.............many are interested in a planked wooden build.....................Derek O0
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Derek Warner

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