CS23 Build Config: Open Deck / Closed Transom

Power Boats only. Please include the boat type in your question.
rsiedl
New Poster
New Poster
Posts: 4
Joined: Mon Sep 06, 2021 11:49 am
Location: Perth, Australia

CS23 Build Config: Open Deck / Closed Transom

Post by rsiedl »

I've received my CS23 plans and have been engrossed in them for the last couple of days :D

I'm planning to build the Open Deck version with a Closed Transom and just have a few questions regarding how I should read the plan.

1. In document B245/3_OV, Frame A2 doesn't list a measurement for the chine. I though perhaps it might translate from Frame A in the Regular (Long Deck) version, but as it sits in a different location, I don't think this is the case. Could you please tell me where I should be looking for that dimension?

2. Also on the same doc, Frame D seems to be misaligned to the BL?

3. For the Closed Transom, I'm looking at document B245/2_CT and I can see a Frame F which should be placed 149mm from the Transom but I don't think I should be removing Station F from the Regular plans as that would leave too great a distance between bulkheads? If I leave Station F in the original position, does it need to be converted to Frames and if so, Frames specific to the Open Deck version?

I've done a mock up of the Regular version and everything seems to line up, so my hopes are high I'm going to be able to achieve this :)

Image

I know others have built the Closed Transom already so I'm sure it's just my understanding of the methodology that is holding me up. Any assistance you could provide would be greatly appreciated.

Cheers,
Reagen



jacquesmm
Site Admin
Site Admin
Posts: 27995
Joined: Wed Aug 14, 2002 1:00 am
Location: Florida USA
Contact:

Re: CS23 Build Config: Open Deck / Closed Transom

Post by jacquesmm »

Before we discuss each point, let's note that every version has exactly the same hull, the same shell. the decks are different and a few frames are different.
Because the hulls are identical, they are all built with molds based on the stations drawings. The plug is made from molds that use the stations drawing.
Later, we will drop frames in there that are slightly different and located in other places but use only the stations drawing to build the mold.

To the questions:
B245/3_OV, Frame A2 and A: I do not show the outside (perimeter) dimensions for the frames, only the inside parts. You should take the outside dimensions from the assembled hull. I could show them but after the fiberglassing, they will be different anyway. There is a small difference in location from the molds but since we do not use those frames to build the hull, it does not matter.
If you want, I will supply a station drawing for those two but, please, not use them for the molds and do not cut hem in advance, you would waste good plywood. With the slits for the flared bow and the fiberglass build up in the corners, my dimensions will not fit. Those dimensions are usefull for the nesting but when time comes to cut the frames, take the dimensions from the assembled hull.

Frame D misaligned: yes, the BL should be the lower face of the sole but on that drawing, no dimensions are taken from that BL. As for the other frames, those drawings show the inside cuts of the frames and those are taken from the proper line, they are correct. Thank you noticing that, I will slide the whole thing down a little bit, it is annoying.

Closed transom, frame F: there is an additional frame. You guessed correctly, the panel span would be too long without it. You add a frame behind F for that version but you do not remove the original, standard frame F, the one at 583 mm from the transom.
In other words, you have one more frame, behind F and the transom. I show the dimensions and location for that frame.
I should have named that additional frame F2.
Jacques Mertens - Designer
http://boatbuildercentral.com

rsiedl
New Poster
New Poster
Posts: 4
Joined: Mon Sep 06, 2021 11:49 am
Location: Perth, Australia

Re: CS23 Build Config: Open Deck / Closed Transom

Post by rsiedl »

Hi Jacques,

Thanks very much for getting back to me so quickly.

The plug is made from molds that use the stations drawing.
Later, we will drop frames in there that are slightly different and located in other places but use only the stations drawing to build the mold.


Got it, thanks! That does clear things up.

I was planning on using the marine ply to make up the molds and then cut down the frames from them once I do the flip. However "B245/3_OV, Frame A2 and A" are going to be larger than Frame 0 and Station A, due to being placed further back from the origin, so I guess those molds will have to be made from throw away material? Or would you recommend all molds be made from thow away material?

B245/3_OV, Frame A2 and A - If you want, I will supply a station drawing for those two

If it's not too much trouble, that would be great. It would be very useful as a starting point for cutting those frames and cross-referencing to the the actual hull dimensions, as well as nesting.

but, please, not use them for the molds and do not cut hem in advance

I wont :)

but you do not remove the original, standard frame F, the one at 583 mm from the transom.

Are there dimensions for converting Frame F (not F2) into an OV version, or should I plan to extrapolate that from the assembly once the deck, etc is in place?

Also, there seems to be a funny extra line on the top right of "E245/4 Station F". Is that anything to worry about? Is the camber of 79mm from the externals (1083mm), or off centred?

Image

Again, thanks very much for your help. Really loving everything about this process (planning, support, community) so far. I'm sure my enthusiasm will drop some once I begin glass sanding :)

Cheers,
Reagen

rsiedl
New Poster
New Poster
Posts: 4
Joined: Mon Sep 06, 2021 11:49 am
Location: Perth, Australia

Re: CS23 Build Config: Open Deck / Closed Transom

Post by rsiedl »

Further to my questions above, I was reading the build notes and it says for the Transom on the "bracket version":

use 5 layers (of 1/2" plywood) for the transom, no clamping board.

However the Motorwell Side diagram on B245/2_CT, clearly shows a step where the clamping board would be.

Which way should I build it?

Edit: Would doing a full transom at 2 1/2" be enough reinforcement to allow installing a transom door?

Cheers
Reagen

jacquesmm
Site Admin
Site Admin
Posts: 27995
Joined: Wed Aug 14, 2002 1:00 am
Location: Florida USA
Contact:

Re: CS23 Build Config: Open Deck / Closed Transom

Post by jacquesmm »

Molds: I recommend throw away molds for all of them. It would be easier to stick to the standard method.

Now, you say that you will not use those 2 frames as molds. In that case, use the standard molds to take dimensions for the frames. With the fiberglass thickness added, they are very close to the frames shape. This was reported by a builder that did build two of those CS23's.
Are there dimensions for converting Frame F (not F2) into an OV version, or should I plan to extrapolate that from the assembly once the deck, etc is in place?
I don't understand that question, sorry. Do you plan to customize something?

The camber of F is an arc measured from the middle but, do not cut that camber on the mold unless you want to use it as a jig later when cutting the upper frames.

Transom thickness: 5 layers but some builders have used a 5 layers clamping board only to save plywood. Check the bolting pattern of you bracket and choose what you prefer.

Door: possible but will require braces on each side. Ideally, the opening should be above the level of the clamping board even if you do not use a clamping board.
You get that dimension from any of the transom drawings.
Jacques Mertens - Designer
http://boatbuildercentral.com

Post Reply

Who is online

Users browsing this forum: No registered users and 5 guests