Member postings for Tim Rowe

The Hitec drum winch is set up as a single line so it need a tensioner to stop the line coming off the drum. The sheet travel is around 270mm so that is a lot of stretch for the rubber tensioner. One way to deal with this is to take the rubber to a turning block in the bow and then bring it back aft. The longer the better as it is best the still have the least amount of tension possible with the booms sheeted in but still some tension when sheeted fully out.

The anchor plate is a piece of T section aluminium extrusion drill out to make glue "rivets" and a brass block courtesy of some random Billing fittings.

The turning block was glued as far forward as possible. The line goes back to the sheet connector on deck and is tied to a stainless steel ring to which the rubber is also attached. The ring stops the knots getting accidently pulled through the block and jamming.

The rubber is led back into the mid section where it is crimper to a ring. The line goes back to the look that retains the drain plug and the tension can be adjusted with the bowsie. Over time the rubber relaxes so the tension has to be restored. It is set up so that there is some residual tension with the sheets fully out with a small safety margin to allow for an offset trim position on the Tx.

The tensioner is the middle of the group of three. The marker on the deck is a visual warning. If the little flag on the sheet line goes forward of the arrow marker the tension has gone and the line will fall off the drum. That would mean taking off the patch and re-setting. Scuse the dust!!

Tim R

Hi Chris

What a great way to get on the water. I spend too much time building and living right next to the harbour I should make more use of it.

Atmospheric photo ghosting along.

Tim R

Hello Ian and welcome!

Are you in Spain?

I don't know what the yacht is but it looks like a GRP hull that will polish up nicely. It's a kind of stand-off scale and I sure will turn into a lovely working model. It won't be too difficult to rig.

What is the weight, beam and draft as a matter of interest?

Tim R

That looks fabulous Ray.

I am not sure that twin rudders would make that much difference in reality. Much more seamanlike to do as yo do and anticipate.

Tim R

Hi Eddie

The method I describe really comes into its own if you are racing and need to change rigs due to changes in wind speed. Normally you have very little time so having everything pre-set as much as possible helps a lot.

The rules say that nothing must project outside the line of the deck so in that case the risk of snagging should be very low. Admittedly if the loops for the shrouds are very close to the deck edge you are limited in choice.

Tim R

In reality there hasn't bee a great deal to do to the rig. The main consequence of lowering the mast was adjusting the shroud and backstay lengths.

This is what we had originally with some very deep hooks. These are real pain as it is necessary to unwind the rigging screws every time the rig is removed. This means you loose the tension setting you have been so carefully tweaking over the last few outings.



With careful measuring after setting the hull horizontal and the mast truly plumb the old hooks were ground off with a cutting disc in a Dremel. The shrouds weren't an equal length anyway hence the difference in the offcuts.

Now cut to equal length and with plenty of adjustment on the rigging screw, the wire was bent to a shallow hook. This means that if I release the forestay or jib swivel, the mast can be leaned back and the hook can be slipped out of the eye. No need to touch the rigging screws unless wanted.

Most people tend to place the hook from the outside - in because it is slightly easier than the orientation in the picture. The picture shows the safe way because if the lee rigging goes slack the hook won't fall out. Other way round and it can, with the risk of breaking the mast.

Tim R

Double post but will make use of it by saying I will visit the AMBO on FB

Tim R

Edited By Tim Rowe on 26/04/2021 20:29:36

Hello Ray

Thanks. I have arranged to be able to move the fine keel forward for the big rig but I will go into the detail in your TSB thread where I am going to post some pictures and notes.

The big rig looks the business.

Tim R

Hello Ray

I am toying with the big rig as an option.

In what way is the boat out of balance? Is this in the sense of lee helm or weather helm? Or simply a matter of stability?

Thanks

Tim R

Excellent news Eddie

Tim R

My eldest son has just bought me a subscription for the PAPER copy and as he said, not much more to include the digital version for my 65 birthday. Not that I am even close to being able to retire.

I like the plans (RCME aircraft plans as well, even if I am not going to build them. I tell myself I might but anyway I get much pleasure from simply poring over the plans. One can learn a lot from that without having to build.

In fact I like Ray's The Cigarette so much I am building two identical ones at the same time. One keeps the name The Cigarette and the other is called Beep Beep which is fitted with surface drives and currently for sale in Italy if anyone wants to take a punt - a pretty fast punt that is!

It seems like a certain poster doesn't have much of interest outside of this topic so I don't think I will miss much if I press the ignore button.

There we go..........

Tim R

Hello Chris

Narrow beam is definitely the way things are going across all classes and an interesting comparison in the photo.

It looks like a very well thought out package - mmmm!

Tim R

Hello Chris.

Is it true you are building a TSB? That would be a good one to follow.

Tim R

Another compliment for the photo.

Ray Is correct. I have just started build a Thames Barge from the drawings of Veronica that he kindly gave me. These were the pre-corrected drawings where a couple of the midship section frames were way off but Ray had dealt with that along with drawing in the tabs to build the hull upside down from a common datum.

Actually I am building a tribute barge called Kimberley. When I ran a small boatyard back in the 80s Kimberley was moored alongside one of the old Itchen chain ferries that we converted into a workshop. It was remarkable in that it was the largest boat in the yard, I went onboard frequently to check and to pump it out and although old and already starting to fall apart quicker than it was being put together, it was owned by an early adopter who had one of the first and huge Vodafones which was basically an ordinary phone stuck on top of a car battery. He had big plans for the boat but sadly it never worked out. Not really surprising given the huge costs of properly restoring and maintaining a Thames Barge.

Some short time previously I had my own brief romance with a barge. My then wife and I decided that we should live on a boat. It doesn't take long to find a range of options and we spotted an old ammunition barge in an estate agent's advert which led to us trekking through the marshes on the Bursledon side of the Hamble River to find Barge Tim. Of course this was seen as instant karma so we triumphed over the rickety walkway to get onboard. The barge was high up in the creek and from the tide marks on the hull it looked like it only floated at high spring tides. Down below it was full of character, and heavily laced with that distinct aroma that tells you, you are on a wooden boat. It was dirt cheap which on its own should have been a sufficient warming sign but gripped with enthusiasm that only seemed to reinforce the karma. It was only when we saw that there were some tide marks inside the boat that we clicked out of our dream state. Be warned. That was a close shave. In the end we went to Holland and bought a steel Dutch barge which turned out to be a great success but that's another story.

Kimberley was built in 1900 by John & Herbert Cann, Harwich. The boat was owned by Fison so would have been engaged principally in the transport of fertiliser. The other end of her life was with Mr Mobile Phone man who took her to the Hamble where she exists as a wreck. If you follow this link there is some interesting stuff about the boat from an archaeological viewpoint. Scroll through to page 41 although the whole paper is a good read.

I have done my own research on the boat and found two photos that I think are of Kimberley. This is one of them.

Tim R

Hello Carl

Just to remind you what Ashley said. I don't think any of us would live long enough for a model yacht mast to fail due to cycle / stress. On your boat you don't need to have a bendy mast. The rigging should keep it in column more or less.

A lot of what is called carbon tubs and rod is not what you might think at all. It is black but the black is in the resin and possibly carbon black used as a pigment. The fibres are glass (ie white), totally unidirectional and very closely packed to give a high glass to resin ratio. I have some tapered glider fuselages that are extremely light, a mixture of carbon and aramid and you can see the tows very easily through the clear resin. The wall thickness is a fraction of the faux carbon rods and tubes but the faux materials are fine for our purpose.
The most likely way of splitting the unidirectional is when attaching fittings with screws (often of the self tapping type). A pilot hole only is drilled and the screws engage with the material in its least resistant plane splitting it. That's why I I try to use adhesives only and if I can't get a large enough gluing area, insert a pin. The pin goes into a close fit hole and therefore acts like a rivet which clamps with very little expanding force.

You are clearly highly qualified engineer but this is probably leading you to over-think everything. Our models are usually hugely over-built with enormous margins of safety compared with what you are used to. Most model I suspect are either damaged by pets (in my case!) dropping or loading into the car.

I am enjoying your posts as you raise interesting questions about which most of us take for granted. Most of all you should finish your model as frankly there are no difficult technical obstacles and the satisfaction you get when it hits the water will bring you a rosy glow.

Tim R

Hello Eddie

I will check out his setting up tips.

The reason I asked is that all the information I have seen to date is that the pre-bend is in the opposite direction and important for the A Rig so that you can get sufficient forestay tension. In light winds the backstay tension puts the mast straight and at the top end of the A Rig range the backstay tension is increased to flatten out the luff allowance and twist off the the top of the mainsail to de-power it.

Interesting to see what Frank says.

Tim R

Hello Eddie

Slipping along very nicely. Great photos and great mast bending tool.

I am intrigued. Which way are you bending your mast? In the relaxed state does bow forwards or backwards in the middle?

It was a bit too windy for a trial sail of the Boxkite at the weekend. Hoping to have better conditions this weekend.

Tim R

A few little jobs to do. Like sorting out the bung.

This was the original arrangement with a retaining string attached to the backstay fitting. I decided to lead the string inside the boat as it would be one less thing to catch on.

Which meant gluing an attachment point inside the hull. This has a dual purpose that I will come to later.



The new string now leads into the boat and I fitted a short length of aluminium tube reamed out as far as I dared with a taper. The original hole in the ply deck was a bit ragged and I thought it would leak. Water will always get into a boat but I want to give it a hard time.



Now firmly in place.

The tiny deck patch covers the top of the rudder tube for good measure.

Tim R

Hello Eddie

I didn't know that and it was difficult to see into the bottom of the hole. I will have a closer look and see if I have to round it off. That would mean a new plug if the mast went any lower as the vang gooseneck would hit the deck. What I might do instead is drip some epoxy into the bottom of the hole to make a flat base. If I overdo it I can always take a fraction off the plug.

I am not too concerned about stopping the mast from rotating as the tension in the shrouds acting through the spreaders seems to be good enough. That is the only thing stopping the mast rotating on the Topiko.

Thanks for the heads-up. It sounds like a good idea.

I bet the Ellipsis drawings are exciting. It will be very interesting to see the form difference from the Nimbus.

Tim R

Moving on to the rig there was a fair bit to do. It had all the bits and pieces but I found out quite quickly that it was not the original or proper mast for the boat. My friend had puzzled over that too. This was not a disappointment however because the spars, fittings and sails were from SailsEtc and all in good shape.



As delivered the first thing to note was that the mast was too long at the lower end. You can see that the boom vang gooseneck is a long way above the deck. Also with the rigging screws wound as as far as one could dare, the mast was raked back at an alarming angle leaving a huge gap under the jib. I wanted to get the mast as low as possible because this would still not be an extreme position according to the rules.



Taking out the rig (The big A rig) and stripping off the fittings for cleaning I found that the base of the mast had a wooden dowel plug inserted, glued and riveted through the aluminium tube. There was also a loose piece of roughly carved wood in the mast hole acting as a further extension. All a bit messy and the wood was a bit pointy concentrating the load in the mast box.



The short piece was the loose insert and the long piece the riveted dowel. I have no idea why it was so long and the only way I could get it out was with a blow torch to burn off the epoxy. Taking care with the very smelly fumes and equal care not to melt the aluminium it came out. Heating aluminium is tricky because it melts before it gets visibly red hot so you get no warning. Now I have a bare mast and can make the mast the exact length I want.



The wood insert was replaced with a shouldered Delrin plug turned to be a push fit in the mast section.



And the finished job with a nice flat bottom to spread the load in the keel box. No fastenings needed because it is always in compression against the shoulder.