TX18 Centre stringer fit and modification

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Vundu
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Re: TX18 Centre stringer fit and modification

Post by Vundu »

Thanks Dougster, at least 2 of us agree :lol: :lol: . I think at this stage it's a case of waiting for JM to get back and see what he thinks. May need to open a new thread as the guys have advised, but would prefer to see if JM see's this first.

fallguy1000
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Re: TX18 Centre stringer fit and modification

Post by fallguy1000 »

So, to simplify things, you are finding a detail in the plans it appears.

The way to correct this would be relatively simple. But this is all conjecture from me and a way for dialogue, not more.

You are 5mm big at one BH and 12mm big at MW, so you have a 7mm rise in the run from BH to MW. That rise extends to the transom and so what you could do as an option would be to calculate the error in the transom which will be on the order of say 15mm. Then you might be able to cut that 15mm vee into the transom and lower the stringer, retain the inverted shape, etc.

Just offered as an idea. The designer really is the one to decide. But you could calculate the amount needed to keep the stringer flat.

If the waterlines are marked on the parts, that would help as well to make sure the sole is a consistent amount above the waterline at all transverse members.
My boat build is here -------->

viewtopic.php?f=12&t=62495

Vundu
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Re: TX18 Centre stringer fit and modification

Post by Vundu »

Hi Fallguy, Thanks for the input. I'll have another look monday. The transom fit is perfect though.

Been looking at your build, Fantastic! The build quality is excellent. I am going to be on a steep learning curve here.

fallguy1000
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Re: TX18 Centre stringer fit and modification

Post by fallguy1000 »

Vundu wrote: Sat Oct 30, 2021 12:45 pm The transom fit is perfect though.
Respectfully, just because the transom and stringer touch each other doesn't mean they are correct (at this point).

Ultimately, it sounds like some minor adjustment in the plans is needed. Don't build a vee!!!!
My boat build is here -------->

viewtopic.php?f=12&t=62495

TomW1
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Re: TX18 Centre stringer fit and modification

Post by TomW1 »

For some reasoon this post did not post. All dimensions must be increased by 10% 10% to maintain the strength of the boat. Since the stringers and frames are widened out there height must be increased to support more weight, just like in a hpuse the beams must increase height the longer they span.

Vandu did you read the Instructions on Scaling I posted, it should have answered all your questions as it was written by Jacques.

Also post a question to Question to Jacques in the section above this Questions Before **** with a title like Scaling the TX18 he watches that section closer than any other.

Tom
Restored Mirror Dinghy, Bought OD18 built by CL, Westlawn School of Yacht Design courses. LT US Navy 1970-1978

TomW1
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Re: TX18 Centre stringer fit and modification

Post by TomW1 »

fallguy1000 wrote: Sat Oct 30, 2021 12:22 pm So, to simplify things, you are finding a detail in the plans it appears.

The way to correct this would be relatively simple. But this is all conjecture from me and a way for dialogue, not more.

You are 5mm big at one BH and 12mm big at MW, so you have a 7mm rise in the run from BH to MW. That rise extends to the transom and so what you could do as an option would be to calculate the error in the transom which will be on the order of say 15mm. Then you might be able to cut that 15mm vee into the transom and lower the stringer, retain the inverted shape, etc.

Just offered as an idea. The designer really is the one to decide. But you could calculate the amount needed to keep the stringer flat.

If the waterlines are marked on the parts, that would help as well to make sure the sole is a consistent amount above the waterline at all transverse members.
fallguy quit talking about the waterline, please. He needs to use the baseline. Waterline varies by weight, baseline is a constant. That is why Jacques uses it to take all measurements from.

Tom
Last edited by TomW1 on Sat Oct 30, 2021 2:12 pm, edited 1 time in total.
Restored Mirror Dinghy, Bought OD18 built by CL, Westlawn School of Yacht Design courses. LT US Navy 1970-1978

Vundu
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Re: TX18 Centre stringer fit and modification

Post by Vundu »

TomW1 wrote: Sat Oct 30, 2021 1:54 pm For some reasoon this post did not post. All dimensions must be increased by 10% 10% to maintain the strength of the boat. Since the stringers and frames are widened out there height must be increased to support more weight, just like in a hpuse the beams must increase height the longer they span.

Vandu did you read the Instructions on Scaling I posted, it should have answered all your questions as it was written by Jacques.

Also post a question to Question to Jacques in the section above this Questions Before **** with a title like Scaling the TX18 he watches that section closer than any other.

Tom
Hi Tom,
Thanks for all the help. I did read the scaling tutorial thanks. Also, in the write up on the TX18 it says we can lift the sole. I understand JM is away on holiday for a few days yet. I'll repost as advised Monday/Tuesday.

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Re: TX18 Centre stringer fit and modification

Post by jonnymac »

(boat in its natural orientation) looking at the underhull form on the study plans, the center line of the bottom looks to be above the transom and as it goes aft it meets the transom. I would take a look back at the plans again and think about what straight means. It means several points are in the same line. it doesn’t mean parallel to another line, perpendicular to transom.

Also, the best way to get someone’s attention on the forum is to quote their user name like this. and ask you question. that way they get a notification. Otherwise you are relying on Jacques to just read through the forum.
Vundu wrote: Sat Oct 30, 2021 2:02 pm

Vundu
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Re: TX18 Centre stringer fit and modification

Post by Vundu »

jacquesmm wrote: Thu Oct 28, 2021 8:35 am It must be straight. That is why I wrote "straight above that line. I don't know why there is second line with a camber superposed on it.
I will check my version of the drawing later today: I am on the road now.
Hi Jacques, I've done some more work on my TX20 centre stringer glitch. I would be very grateful if I could have your thoughts on the curve line superimposed in the photos and the way I have scaled the 10%.

Thanks.

Vundu
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Re: TX18 Centre stringer fit and modification

Post by Vundu »

jacquesmm wrote: Thu Oct 28, 2021 8:35 am It must be straight. That is why I wrote "straight above that line. I don't know why there is second line with a camber superposed on it.
I will check my version of the drawing later today: I am on the road now.
HI Jaques, Please could you take a quick look at this thread and confirm if I am scaling right and maybe shed some more light on the centre stringer glitch I have. Thanks.

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