Thanks Will
Might be a little time as away on holiday for a week at the moment, back for a week and then away again. But can't wait to see how it performs as it is different (for me) from my prop shaft models and is probably the only Huntress with a stern-drive ever built.
Chris
Might be a little time as away on holiday for a week at the moment, back for a week and then away again. But can't wait to see how it performs as it is different (for me) from my prop shaft models and is probably the only Huntress with a stern-drive ever built.
Chris
Scratch building 7 Faireys at a scale of 1:12
Well done with your progress Chris.
Exciting news that a lake test is well in your sights.
I for one am looking forward to hearing how well she performed.
Will
Well done with your progress Chris.
Exciting news that a lake test is well in your sights.
I for one am looking forward to hearing how well she performed.
Flaxybuck - no problem, some folks get arsy on other forums when someone dares to go off thread but I take the view if we were face to face having a chat other things would be discussed and some useful and interesting things often come up. Some threads would be very short if we stuck rigidly to the subject!
As Rod says your hull will have no problem getting on the plane. It is similar to my Fairey hulls which are deep vee which were designed to give a more comfortable ride in rough seas than more flat bottomed boats.
Flaxybuck - no problem, some folks get arsy on other forums when someone dares to go off thread but I take the view if we were face to face having a chat other things would be discussed and some useful and interesting things often come up. Some threads would be very short if we stuck rigidly to the subject!
As Rod says your hull will have no problem getting on the plane. It is similar to my Fairey hulls which are deep vee which were designed to give a more comfortable ride in rough seas than more flat bottomed boats.
Hi Chris. My apologies for going off at a tangent about running strakes when your post is about progress on your Huntress. I really appreciate how well you are finishing your boat both inside and out. The interior is looking especially good both in terms of the neatness of the installations and the quality of your work. Well done. Too often we see boats looking good on the water only to find a snakes nest when you look inside amidst an unfinished or poorly finished interior.
I look forward to seeing more of your Huntress.😉😉
Hi Chris. My apologies for going off at a tangent about running strakes when your post is about progress on your Huntress. I really appreciate how well you are finishing your boat both inside and out. The interior is looking especially good both in terms of the neatness of the installations and the quality of your work. Well done. Too often we see boats looking good on the water only to find a snakes nest when you look inside amidst an unfinished or poorly finished interior.
I look forward to seeing more of your Huntress.😉😉
Flaxbybuck, you hav underestimated your skill as a marine architect. A deep-V hull is a type of planing hull. Simply said, a planing hull lies on top of the water, instead of in it. This makes it A LOT faster than displacement hulls, but they also handle poorly in rough water. Even with small waves, most planing hulls will be incredibly bumpy and wet. In contrast, displacement hulls are usually round on the bottom with ballast placed low in the center. At rest, round hulls tend to roll with the waves and swells.
Flaxbybuck, you hav underestimated your skill as a marine architect. A deep-V hull is a type of planing hull. Simply said, a planing hull lies on top of the water, instead of in it. This makes it A LOT faster than displacement hulls, but they also handle poorly in rough water. Even with small waves, most planing hulls will be incredibly bumpy and wet. In contrast, displacement hulls are usually round on the bottom with ballast placed low in the center. At rest, round hulls tend to roll with the waves and swells.
Chris,
The hull shown in my pic is a design of my own making. It is a deep V hull and as such is not expected to rise onto the plane. Nevertheless I have included rubbing strakes in the belief that they will provide added directional stability. Time will tell !
When I was much younger I used to go windsurfing, and recall how the design of boards changed almost every year. Some time in the 1980s the equivalent of rubbing strakes were introduced, the object being to reduce or stop the board from sliding sideways across the water. At speed windsurfing boards would get onto the plane and would have this sliding tendency. The only component to counter this was the presence of one or more fins, plus the dagger board. However, when sailing before the wind the dagger board would be totally retracted, and this I guess is where the presence of rubbing strakes helped directional stability.
As to the arrangement of the rubbing strakes on my hull - to be honest, a complete guess. I have noticed that many different arrangements are used on model boats (three different ones on this post alone !)
This brings into question their very function. My guess would be:
1. To protect the bottom of the boat when grounding, and
2. To assist in lifting a hull onto the plane
in which case my use of them on a deep V hull is totally useless ! (So much for my qualities as a marine designer)
But, I have started so I will finish - the boat that is, and let you know how it performs. I have worked on the boat for two years now so please don't hold your breath !!😉
Chris,
The hull shown in my pic is a design of my own making. It is a deep V hull and as such is not expected to rise onto the plane. Nevertheless I have included rubbing strakes in the belief that they will provide added directional stability. Time will tell !
When I was much younger I used to go windsurfing, and recall how the design of boards changed almost every year. Some time in the 1980s the equivalent of rubbing strakes were introduced, the object being to reduce or stop the board from sliding sideways across the water. At speed windsurfing boards would get onto the plane and would have this sliding tendency. The only component to counter this was the presence of one or more fins, plus the dagger board. However, when sailing before the wind the dagger board would be totally retracted, and this I guess is where the presence of rubbing strakes helped directional stability.
As to the arrangement of the rubbing strakes on my hull - to be honest, a complete guess. I have noticed that many different arrangements are used on model boats (three different ones on this post alone !)
This brings into question their very function. My guess would be:
1. To protect the bottom of the boat when grounding, and
2. To assist in lifting a hull onto the plane
in which case my use of them on a deep V hull is totally useless ! (So much for my qualities as a marine designer)
But, I have started so I will finish - the boat that is, and let you know how it performs. I have worked on the boat for two years now so please don't hold your breath !!😉
Did some Googling on strakes and as I guessed the lads with very fast/racing boats do in some cases fit strakes for purposes other than creating lift to get on the plane.
They fit them to reduce the amount of sliding and running wide in fast turns. In some cases to stop the boat tripping over its keel as it slides, forcing the boat to sit upright and causing the "driver" to lift off the power. It varies from boat to boat and not all of them benefit from or need strakes.
I know that full-sized Faireys can have different layouts of strakes on the same model e.g. they can run either parallel to the keel or the chines and finish differently at the bow. I doubt that there is much difference in practice though.
Flaxybuck, what is that hull of yours for, as it is unusual to have the strakes like that at the bow?
Here is my Huntsman 31 build which is different again!
Chris
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Did some Googling on strakes and as I guessed the lads with very fast/racing boats do in some cases fit strakes for purposes other than creating lift to get on the plane.
They fit them to reduce the amount of sliding and running wide in fast turns. In some cases to stop the boat tripping over its keel as it slides, forcing the boat to sit upright and causing the "driver" to lift off the power. It varies from boat to boat and not all of them benefit from or need strakes.
I know that full-sized Faireys can have different layouts of strakes on the same model e.g. they can run either parallel to the keel or the chines and finish differently at the bow. I doubt that there is much difference in practice though.
Flaxybuck, what is that hull of yours for, as it is unusual to have the strakes like that at the bow?
Here is my Huntsman 31 build which is different again!
Hi Rod C
Many thanks for your post. Flaxbybuck had a point that I did not address his query directly, - - but that is because even with scale models we must consider models and real craft quite differently.
Faced with heavy "sticky" water and effectively hurricane force winds, our tiny models certainly sail in a "challenging" environment!
As Buck says, strakes are a separate matter; and I have yet to be convinced they are strickly necessary.
Nevertheless I think we all agree that either by good hull design or by additional strakes; our models must get out of the water and on to the plane to go fast. Otherwise all our wonderful power is just wasted in making a huge wash!!
Happy sailing.
Dr John F Leeds and Bradford MBC. 😊😊😊
Many thanks for your post. Flaxbybuck had a point that I did not address his query directly, - - but that is because even with scale models we must consider models and real craft quite differently.
Faced with heavy "sticky" water and effectively hurricane force winds, our tiny models certainly sail in a "challenging" environment!
As Buck says, strakes are a separate matter; and I have yet to be convinced they are strickly necessary.
Nevertheless I think we all agree that either by good hull design or by additional strakes; our models must get out of the water and on to the plane to go fast. Otherwise all our wonderful power is just wasted in making a huge wash!!
Rod - I think that was due more to the power, or lack of, of the engine!
When I was young we had a Fletcher speed boat which initially we fitted with a 40hp Evinrude from another boat. It did get on the plane but the performance was just adequate. We later replaced it with a 70hp Volvo Penta and it performed well, though it used to go through a 5 gallon tank of 2-stroke in a short time on full chat!
Even that is small by today's standards and some of them are the price of a small car!
Chris
Rod - I think that was due more to the power, or lack of, of the engine!
When I was young we had a Fletcher speed boat which initially we fitted with a 40hp Evinrude from another boat. It did get on the plane but the performance was just adequate. We later replaced it with a 70hp Volvo Penta and it performed well, though it used to go through a 5 gallon tank of 2-stroke in a short time on full chat!
Even that is small by today's standards and some of them are the price of a small car!
Dr John, your very long post is much appreciated. Now i finally understand why my childhood vessel performed as it did. A very very heavy yacht tender that barely got on plane via my grandfather's 9.6HP JOHNSON outboard. Thank you for taking the time, it's truly appreciated. I'm not going to bother with such details below the waterline. I understand the need for a keel to avoid being blown off course, but i dont see the need for anything else down there.
Dr John, your very long post is much appreciated. Now i finally understand why my childhood vessel performed as it did. A very very heavy yacht tender that barely got on plane via my grandfather's 9.6HP JOHNSON outboard. Thank you for taking the time, it's truly appreciated. I'm not going to bother with such details below the waterline. I understand the need for a keel to avoid being blown off course, but i dont see the need for anything else down there.
I've finished the RC installation apart from fixing the Rx and switch in place and it works!
Will do another bath test to check for leaks and can then try on the lake.
Chris
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With our examples I don't think it matters as the part of the strakes that connect with the keel or chine rail are mainly out of the water as speed increases and the bow comes up - they could be stopped short of the bow really. At lower speeds they are more effective as spray rails.
As you can see with my Huntsman 28 hull in the first photo I stopped the strakes short of the transom, as per the full-sized boat, which are laid out like that to suit the twin props - I've only used one though and on other builds I've run them to the transom. Only for the look really as you don't need strakes at the rear either. So you could just fit strakes to the middle part of the hull but it would look a little weird. In fact model boats don't need strakes at all, because as John says they have plenty of power and don't need the lift generated by them - my Club 500 doesn't have strakes and has no problem getting on the plane. It may be that the fact that water isn't to scale actually helps models to get on the plane? I don't build light as I think heavier models sit on the water better and handle better and with brushless motors power isn't a problem. They get onto the plane quickly and the hump that full-size boats go through doesn't seem as significant due to their lighter weight.
I doubt that you find any scientific data on strakes/spray rails as regards model boats as they don't really matter and I think are usually only applied because the full-size craft has them or for aesthetics. Unless the racing boys consider them, though that may be for other reasons like stability?
Chris
With our examples I don't think it matters as the part of the strakes that connect with the keel or chine rail are mainly out of the water as speed increases and the bow comes up - they could be stopped short of the bow really. At lower speeds they are more effective as spray rails.
As you can see with my Huntsman 28 hull in the first photo I stopped the strakes short of the transom, as per the full-sized boat, which are laid out like that to suit the twin props - I've only used one though and on other builds I've run them to the transom. Only for the look really as you don't need strakes at the rear either. So you could just fit strakes to the middle part of the hull but it would look a little weird. In fact model boats don't need strakes at all, because as John says they have plenty of power and don't need the lift generated by them - my Club 500 doesn't have strakes and has no problem getting on the plane. It may be that the fact that water isn't to scale actually helps models to get on the plane? I don't build light as I think heavier models sit on the water better and handle better and with brushless motors power isn't a problem. They get onto the plane quickly and the hump that full-size boats go through doesn't seem as significant due to their lighter weight.
I doubt that you find any scientific data on strakes/spray rails as regards model boats as they don't really matter and I think are usually only applied because the full-size craft has them or for aesthetics. Unless the racing boys consider them, though that may be for other reasons like stability?
I'm not sure that your response Dr John goes any way to answering my query concerning comparative performance of different rubbing strake design. In this instance I am not interested in what full size boats might do, only model size boats.
I would love to hear from anyone who can provide factual information that points to one arrangement or design performing better than others. Anyone ?😉
I'm not sure that your response Dr John goes any way to answering my query concerning comparative performance of different rubbing strake design. In this instance I am not interested in what full size boats might do, only model size boats.
I would love to hear from anyone who can provide factual information that points to one arrangement or design performing better than others. Anyone ?😉
Hi Buck,
In considering the desirability of hull strakes for fast or planing models; we really must keep the scaling effect of models against full-time size boats in mind.
We know that scale models always tend to sail well over "scale speed". Due to the cube rule of water displacement, this is mainly due to the models' far superior power-to-weight ratio against their full-size equivalent.
With strictly limited power against their weight, full-size fast boats rely on planing hulls to lift them clear of the water into (far less dense) air. What is more they often use hull strakes to assist getting on to the plane.
Water (and indeed wind!!) cannot be scaled. This "weighty" water has far greater effect on models than on real boats. Indeed, we have often heard that model boats have to sail in heavy treacle and often in hurricane force winds that would drive real boats running for harbour!
In such "sticky treakle" our fast models rely on skimming or planing even more than full size craft. Thus light construction and running strakes are vital in lifting our models clear of the "sticky and wet" stuff at low speeds.
I look forward to seeing your long-awaited "venician" cruiser putting this theory to the test in Yeadon Tarn!
Dr. John. F. Leeds and Bradford BBC. 😁😁😁😁😁😁
In considering the desirability of hull strakes for fast or planing models; we really must keep the scaling effect of models against full-time size boats in mind.
We know that scale models always tend to sail well over "scale speed". Due to the cube rule of water displacement, this is mainly due to the models' far superior power-to-weight ratio against their full-size equivalent.
With strictly limited power against their weight, full-size fast boats rely on planing hulls to lift them clear of the water into (far less dense) air. What is more they often use hull strakes to assist getting on to the plane.
Water (and indeed wind!!) cannot be scaled. This "weighty" water has far greater effect on models than on real boats. Indeed, we have often heard that model boats have to sail in heavy treacle and often in hurricane force winds that would drive real boats running for harbour!
In such "sticky treakle" our fast models rely on skimming or planing even more than full size craft. Thus light construction and running strakes are vital in lifting our models clear of the "sticky and wet" stuff at low speeds.
I look forward to seeing your long-awaited "venician" cruiser putting this theory to the test in Yeadon Tarn!
Seeing your hull design with the chine rail and various rubbing strakes raised a question in my mind, and that is, has anyone carried out any objective research into the most effective arrangement of rubbing strakes ? You will see that on the boat I am making I have carried the strakes through to the keel, whilst you have carried them parallel to the keel, onto the chine rail. I have no idea which might be more effective. Any ideas ?😉
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Seeing your hull design with the chine rail and various rubbing strakes raised a question in my mind, and that is, has anyone carried out any objective research into the most effective arrangement of rubbing strakes ? You will see that on the boat I am making I have carried the strakes through to the keel, whilst you have carried them parallel to the keel, onto the chine rail. I have no idea which might be more effective. Any ideas ?😉
Bit more work on the installation, including building a shelf for the ESC, bolted in to give access to the servo. Just need to extend the motor wires and she's ready to try on the water.
Chris
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Bit more work on the installation, including building a shelf for the ESC, bolted in to give access to the servo. Just need to extend the motor wires and she's ready to try on the water.
Thanks for the full explanation Chris. I attached my strakes using epoxy and learnt the hard way that all excess needs to be cleaned off as soon as possible, and definitely before the stuff hardens solid.🤔
Thanks for the full explanation Chris. I attached my strakes using epoxy and learnt the hard way that all excess needs to be cleaned off as soon as possible, and definitely before the stuff hardens solid.🤔
Thanks for the kind comments.
Yes, the stern-drive is more complicated but as well as the usual Faireys that I'm building I wanted to do something a bit different. Drawings were produced for this version by Fairey Marine with, as well as the stern-drive, a longer cabin with different side windows, but it never actually went into production.
Flaxbybuck - yes, strakes must figure amongst the worst jobs! On larger models some folks have cut the triangular sections on a band saw or planed them but for the small sizes I need it would be very difficult and not something I fancy doing. For my Huntsman 28 I used square section timber which once glued on the hull, which had been finished with Eze-Kote and light-weight cloth, using thick cyano, I then sanded to a half-round shape which doesn't look too bad.
But on the other builds I wanted triangular and as you can't buy timber sections for love or money (well apart from short lengths for use in dolls houses) then I thought about using styrene subject to getting a strong glue bond on the Eze-Kote which I was able to get using Deluxe Materials Canopy Glue. Again a problem getting long lengths but did obtain in the end from Deans Marine, though the postage was very expensive - I did off-set it though to some extent by ordering some brass rod for the pulpit rails.
For both timber and styrene I pre-bent the sections by steaming over the kettle. For the styrene using canopy glue I had to tape in place and leave to set over night. Once set I filled up the sides of each strake with fine filler. All in all a fiddly and time consuming job!
First photo shows those to the Huntsman 28 and the second one those to the Huntress - forgot about all the taping required when using styrene! Third one is the Huntress hull finished.
Chris
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Yes, the stern-drive is more complicated but as well as the usual Faireys that I'm building I wanted to do something a bit different. Drawings were produced for this version by Fairey Marine with, as well as the stern-drive, a longer cabin with different side windows, but it never actually went into production.
Flaxbybuck - yes, strakes must figure amongst the worst jobs! On larger models some folks have cut the triangular sections on a band saw or planed them but for the small sizes I need it would be very difficult and not something I fancy doing. For my Huntsman 28 I used square section timber which once glued on the hull, which had been finished with Eze-Kote and light-weight cloth, using thick cyano, I then sanded to a half-round shape which doesn't look too bad.
But on the other builds I wanted triangular and as you can't buy timber sections for love or money (well apart from short lengths for use in dolls houses) then I thought about using styrene subject to getting a strong glue bond on the Eze-Kote which I was able to get using Deluxe Materials Canopy Glue. Again a problem getting long lengths but did obtain in the end from Deans Marine, though the postage was very expensive - I did off-set it though to some extent by ordering some brass rod for the pulpit rails.
For both timber and styrene I pre-bent the sections by steaming over the kettle. For the styrene using canopy glue I had to tape in place and leave to set over night. Once set I filled up the sides of each strake with fine filler. All in all a fiddly and time consuming job!
First photo shows those to the Huntsman 28 and the second one those to the Huntress - forgot about all the taping required when using styrene! Third one is the Huntress hull finished.
Hi Chris,
Your Huntress is looking great.
Just out of interest, tell us how you shaped and attached the rubbing strakes. I have done some recently and it proved to be a horrible job ! Details later.😉
Hi Chris,
Your Huntress is looking great.
Just out of interest, tell us how you shaped and attached the rubbing strakes. I have done some recently and it proved to be a horrible job ! Details later.😉
Looks great Chris. The stern drive is an extra complication; but your model should turn even tighter than my Swordsman!!
Dr John F. Leeds and Bradford. BBC. 😊😊😐
Builds coming along and I'm working on the part I was looking forward to, that is, installing the hardware. Trouble is I forgot to install the rubber bellows for the steering and I've got to take the stern-drive out again and it was fiddly to install! Hey-ho, serves me right for leaving it for so long!
Chris
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Builds coming along and I'm working on the part I was looking forward to, that is, installing the hardware. Trouble is I forgot to install the rubber bellows for the steering and I've got to take the stern-drive out again and it was fiddly to install! Hey-ho, serves me right for leaving it for so long!
