Bomb vessel cross section - scale 3/8 or 1:32

Dave Stevens (Lumberyard)

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temp001.jpg


This will be what I call a prototype build, the difference between a prototype build and any other build is this one is done as a "how to build the model" and does not focus on refined finishing, the concern here is does it go together as planned and different way to offer the model as a kit. With a kit in mind the project is approached with ways to reproduce parts.
you could say this is more like how to design a kit for production.
 

Dave Stevens (Lumberyard)

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I have to be able to reproduce the parts so first I took the PDF file and converted the drawings in JPEG format so I can import them into CAD and trace them.

jpeg files.JPG



going from a raster image to a vector image requires tracing. Looking close the black line is the JPEG file as drawn the yellow line is the vector tracing in CAD.
Once you begin the CAD drawing everything has to fit each other the red lines show how wide a raster image line is and you can be way off from part to part depending on the accuracy of the tracing.

lines.jpg


step one is to import the raster images into CAD and create a working file. doing this makes all the parts active so you can adjust them, move them, copy them and set them up for laser cutting. Each frame drawing was traced as a complete frame which can now be broken down into separate parts.

what was drawn in the PDF file is not dead accurate, as you see here the left side was traced then mirrored to the right side and you can see the difference between the original and the CAD version of frame 6. Once the CAD work is done the original PDF files are discarded and not used for the build.



frame traced.JPG




working file.JPG
 
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Dave Stevens (Lumberyard)

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I did not trace the frame parts from the PDF file because they are not accurate what I did do was break down the full traced frame and set them up as a cutting file. now I can reproduce laser cut sets of frames over and over.

frame parts1.jpg
 

Dave Stevens (Lumberyard)

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with the laser cutting file done I can now cut the frames

lf1a.jpg


this model is in 3/8 = 1 foot scale so I wanted a wood that looks like wood. some wood such as boxwood or swiss pearwood has no grain figure to it and looks like a solid color. This is not a bad thing it is more of personal taste. What i chose is Birch which has a nice grain figure and a nice tan color.

lf2.jpg


lf3.jpg
 

Dave Stevens (Lumberyard)

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I agree. This one has been a while in the works. It will be nice to see it finally get done. Mine is sitting on the work bench. Haven't had a chance to work on it since last November or so.
this project has a long history or it seems as if does. it began as a building project drawn by Jeff Staudt back in 2010 at the time is was a free download building project by Model Ship builder.

Then it was considered as a possible kit and group build project. The idea was to create a 3D model as a building aid but that never did happen, reasons it was never carried through is unknown. So a group formed to discuss how to go about producing a kit. The group was faced with production issues such as
1 the original drawings had to be converted to cutting files
2 cost of laser cutting
3 should laser parts be offered or just sheet stock and let the builder do the cutting
4 milled wood or rough stock
5 cannons were a big issue first a model had to be made either 3D modeled and printed or machined. Once there was a model should each cannon and mortar be 3D printed or should a master production mold be made and the cannon and mortar cast? or offer no mortar and cannon and let the builder make their own.
6 anyway you look at it there was time and money needed up front and no idea if the project would even be able to recover the investments costs.
7 to hire a 3D artist to create the 3D building aid model was really expensive

in reference to comments by Don in the new forum topic about learning from mistakes to create a group build this is it and Dons comment waiting 2 years is a valid statement. Waiting on different people to complete a task ran from days to months to years. Heck you can't rush anyone willing to volunteer their time and to hire people is very expensive but paid help does get the job done fast and professionally, it was just where does the money come from?

finally after some investments for master models and molds, getting work done one prototype kit was produced and Winston volunteered to build it. But life goes on and things get set aside, Winston is not a dedicated model builder, he actually has a life beyond model ships. but here is the very first prototype build.


so here we are and lets see if a prototype gets built. As Dave b said in his build log this is a hobby and building should be a slow and fun past time. Well I agree but in this case it is build fast and skip the fine details and gloss over the finer finish. This is about designing and how to make it work and not to produce a finely crafted model.
 

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Zoly THIS IS EXACTALLY WHAT I WAS DISCUSSING WITH YOU, again as Dave said we can learn from mistakes it does not HAVE TO BE AN EXACT SAME SITUATION, again WE ARE TALKING THIS THING TO DEATH SOMEONE THAT IS A CAPABLE AND DEDICATED MODEL BUILDER like DAVES or MIKE41 or UWE, or JIMSKEY (JIM), PLEASE NO NEGATIVE RESPONCES NEEDED DAVE STEVENS HAS EXPLAINED ALL THE PROBLEMS ENCOUTERED, otherwise just delete the whole DEAL IT WILL NEVER GET OFF THE GROUND, Zoly there are KITS, PLANS LOGS OF ALL TYPES, EXAMPLE THE HMS ALERT (COMING SOON), THE BOMB KETCH (COMING SOON), LIKE GILLES AND UWE SAID ANCRE PLANS FOR THE SMALL BUILDS, MIKE41 SAID IT BEST IT SHOULD NOT BE A LONG DRAWN OUT COMPLICATED BUILD FOR OBVIOUS REASONS, if we are serious about this let us cut out the problems and consentrate on WHAT CAN BE DONE, after the first project we can then concentrate our efforts on the next ones, IF NO ONE IS INTERESTED IN THIS LET US JUST DROP IT NOW AND NOT WASTE ANY MORE TIME. Don
 

zoly99sask

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Don,we don't have enough members to have multiple group builds and also somebody experienced should build a prototype from the ready plan set,also time consuming.And again Msb « group project « was a project to create a kit with multiple members involved,what I am talking about is group build using a planset and many members joins to build same project from the same planset,completely different thing.
 

donfarr

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ZOLY, IT WILL NOT WORK, LET DAVE STEVENS OR WINSTON DESCRIBE TO YOU MAYBE THEY CAN GET IT ACROSS BETTER THEN I THE SITUATIONS OF MSB PROBLEMS ARE THE PROBLEMS OF GROUP BUILD OR KIT BUILD, DAVE STEVENS HAS DESCRIBED IT PERFECTLY, LOK AT CHRISTIANS REMARKS IN THE NEW FORUM SECVTIONS CHECK WITH BRIAN OR DOC BLAKE, and AS I SAID IN ANOTHER POST DO NOT TAKE MY COMENTS PERSONALLY YOUR VALUE TO THIS SITE IS EMENCE AND NECESSARY, BUT PLEASE, PLEASE, STOP THE NEGATIVES AND CONCENTRATE ON THE POSITVES, ABOUT MORE THEN ONE BUILD ASK BRIAN IF HE IS GOING TO BE BUILDING THE ONTARIO, OR THE BOMB KETCH, ASK DOC BLAKE IF HE IS GOING TO DO THE HMS ALERT, these builds have A SET OF PLANS< A PRTOTYPE AND OTHER ELEMENTS OF WHAT YOU ARE TALKING ABOUT READY TO GO NOW OR (COMING SOON) MIKE41 SAID IT BEST IN HOW MANY ARE NEEDED TO MAKE IT VIABLE and SOME MODELERS WILL DROP OUT AND SOME WILL COME IN LATTER, I HAVE SEEN ALL YOUR COMENTS ZOLY, AND HAVE TAKEN THEM SERIOUSLY, WHAT IS YOUR SOLUTION TO THIS IDEA HOW WOULD YOU HANDEL IT, AND PLEASE DO NOT TAKE OFFENCE AT MY COMENTS. Don
 

Dave Stevens (Lumberyard)

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this build goes on as a proof of concept build and I will present different ways to go about building rather than "this is what I did"
the first task at hand is to assemble the frames. In this hull the frames are single frames and not the sistered frames in other hulls.
right off i will not be using the original frame drawings in the PDF file because those drawings are not exactly like the CAD drawings so i printing the frame directly from the cad file

frame parts.jpg
 

Dave Stevens (Lumberyard)

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what I have to do before I can assemble any frames is to clean up the laser char at the joints.

there is no need for a perfectly clean surface I tried gluing without cleaning the char and cleaning the char I found a little char did not weaken a glued joint so this is what I have.

char1.jpg


however I should have know better when choosing the wood for the frames because different wood reacts differently to a laser cut, from left to right is Beech, Cherry and boxwood no doubt about it the harder and uniform the grain the easier it is to clean the char

char.jpg


looking micro close to the grain of the Birch you can see the softer area with the pits and a darker char.

char2.jpg


now look close at these samples the char is even because the boxwood grain is uniform in texture the Cherry slightly less so.

char3.jpg


looking even closer the char is reacting to the grain of the Cherry by leaving darker streak areas the boxwood with its even texture the laser leaves an even char that cleans off with just a couple passes with a razor blade.

char4.jpg



using Birch was not a good idea for the framing but because I already cut the parts I will continue, I think it will be a bear cleaning off the char on the edges of the frames. but this is about the building process and not the pretty end results.
 

Dave Stevens (Lumberyard)

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pre planning and thinking it out is as much a part of any build as the skill to actually do it.
how do you assemble a frame to match exactly to the drawing? one way is put the drawing on a sheet of dense foam board and put pins along the edge.

fa1.jpg


then place the frame parts against the pins. not a bad idea it will insure the frame is built correctly

fa2.jpg


what I did was to first clamp the floor timber in place on the drawing which is sitting on a piece of window glass to make sure everything is flat. Now i can glue the end of the next frame piece to the end of the floor timber. I am using Super Glue for this and 10 seconds after the two pieces tough they are secure.

fa3.jpg


all i did was line up the edge of the part to the drawing and in 15 minutes i have a complete frame minus the chocks which are next.

fa5.jpg
 
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Dave Stevens (Lumberyard)

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the chocks were cut oversize because the laser beam is around .010 beam which would cut the notch larger and the chock smaller if cut right on the line.

cho2.jpg


if I moved the frame parts and slipped the chock in the notch there would be a gap between parts

cho1.jpg


when gluing up the frame parts make sure the notch for the chock is even like the top image, if it slipped and looks like this that makes fitting the chock a lot harder

cho3.jpg
 

Dave Stevens (Lumberyard)

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my set up for fitting the chocks is a 4 inch disk sander

cho5.jpg


I like working close to the center of the disk because I can control the amount being taken off the piece, along the outer edge cuts much faster than the center.

cho6.jpg


When fitting the chock i take just a tiny light touch and sneak up on the fit.

cho4.jpg
 
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