cutting frames for gunports in a fully framed model

[hamilton]

Hi there:

 

I'm working on the Admiralty models HMS Echo cross-sectional model and had a question about how to cut the toptimbers out to frame the gunports. It seems to me there are at least two possible approaches, and I'm hoping to hear from those more experienced than me how best to approach this (understanding that "best" is both subjective and relative)....

 

1. Complete all frames of the cross-section and then cut the frames off appropriately for the gunports. This method benefits from the strength provided by having all frames in place and with battens added at the top of the toptimbers - though to my mind it seems pretty tricky to cut away the frames even with a small keyhole saw.....

 

2. Shorten the frames that fall in line with the gunport as they are added to the model, reserving the toptimber pieces for the extensions above the gunports - this seems easier in terms of cutting away the frames, but I wonder if there are difficulties that my lack of experience is hiding from me if I go this route....

 

I hope the question is clear......Here is the disposition of frame drawing for clarity - the frames in question are 2-aft and 3-forward. Thanks in advance for any help you can provide!

hamilton

 

Edited July 16 by hamilton

[tmj]

Are you asking about cutting the rabbets for horizontal 'headers' and 'footers' into the vertical sides of the 'jams'?   

[hamilton]

Thanks for the response TMJ, but no - I'm talking about chopping the frame down to lay on the gunport sills and what is the best way to approach this. Here's the photo again with the area highlighted.....

hamilton

 

[tmj]

I might 'still' be getting this wrong, but if my interpretation of your question is actually correct this time... I'd start with cutting out a wooden, or paper pattern to the exact dimensions and shape of the desired gunport. I'd 'then' use a height gauge to set the proper location and level of that gunport and the pattern with the model sitting level and secure in a cradle, or some sort of a 'berth' that will securely hold the model level and not allow it to shift nor list from port to starboard. Lay out your gunport(s) with a fine point pencil, or better yet, an extremely fine knife slice for a mark. Next, cut temporary braces to fit snugly between the surrounding frames, to hold those frames secure while sawing/cutting those frame members and also filing in the rabbets for the horizontal header and footer components. Use a tiny drop of PVA glue to secure those temporary braces in place. Don't use CA. Keep everything proud and use files to get the proper fit(s) without creating any unsightly gaps. File, check fit, file, check fit. Once you have your gunports installed, and everything is securely glued up remove those temporary braces via a knife and some filing to clean up the glue residue. 

I hope that this helps...          

[hamilton]

Thanks TMJ! This bolsters the plan I had in my head but because I've never made a plank-on-frame model before I wanted to test the waters with the community a bit! Thanks again

hamilton

[ERS Rich]

Hi, cutting wood is measuring, marking, and removing the waste.

 

First measure to the location of the cut, with a ruler, divider, or some other reference.

 

Second mark the line to cut, with a fine pencil, then a knife.  Make light passes across the line with a knife to make an indentation known as a stop.  Use a guide, like a block of wood, to make sure the line is horizontal, vertical, or whatever it needs to be.  This is the most important step.  This line needs to be the final location of the cut.  If needed make a practice line on the waste side of the cut, then repeat at the final location.

 

Next remove the waste.  Many ways s to do this.  Easy at first.  I’d drill holes along the center line frame and approach each waste line.  Then cutout the frame with nippers or a knife.  The hard part is approaching the line.  Make small cuts, with say Tamiya mini hand saws.  
 

Another idea is just drill two holes on the waste side of each line, then cut the frame with the Tamiya mini saw.  Or an Exacto Knife.

 

Good luck, figuring out how you’ll do this is part of the woodworking craft.

 

Checkout YouTube for videos on making “stop cuts”

 

 

 

 

 

Edited July 22 by ERS Rich