iMustBeCrazy

I am currently drawing up plans for the Lapwing which should also cover: Lapwing 1816 Fancy 1817 Kite ca1817 Racer ca1819 Sprightly ca1819 Nightingale 1827 Speedy 1828 Snipe 1828 Vigilant 1821 Swift 1821 Basilisk 1822 Bramble 1822

Lots of confusion, this Speedy (1782) is a Brig on a cutter style hull, then there is Speedy (1828) which is a cutter built on the lines of the revenue cutter Lapwing (1816) which I am currently trying to produce drawings for, but it's a slow process.

G'Day all, I have drawn up some scale rulers in CAD. English feet and inches in 1:16, 1:24 and 1:48. EDIT: added 1:32 When printing you may have to adjust your printers scaling until 12 feet on the 1:16 ruler is 9 inches. After printing I cover both sides with Scotch 'Magic' tape before cutting them out. I hope somebody finds them useful. Scale Rulers.pdf

Minor update: As is usual for this sort of project, it reaches a point where to test it you need to use it for the job you built it for and if it works you don't need it and progress stalls. So it was with this project. However, as I can see a need in the near future I have done a little more work including safety guards and some steps towards dust extraction. No chance of the belt hitting me in the face now. On another note, I picked up this at a market for A$20 (US$14) new in box but I'm not sure I got a bargain. It is the worst kind of Chinese product, the drill press used to drill the pulleys and sanding disk wasn't set square so they wobble, the bearings for the axle driving the belt and disk are fixed to sheet metal not the nice solid casting - if you raise the belt to vertical you tilt the disk, if you want to swap belts to a different grit you need to undo 10 screws (holding the dust cover/guard) and loosen 3 bolts. I'm sure it will be useful....... eventually.

I have done or can do similar for any of the other drawings, let me know if you need something and I'll see what I can do.

I've played around with some of the RMG drawings, do these help? ZAZ6345 Basilisk (1822) enlarged Lapwing j8083ab bw.tif ZAZ6345 Basilisk (1822) enlarged Lapwing j8083a.tif

I will certainly be following this. My interest is that an Ancestor sailed on the Lapwing on her journey to Australia and Skylark was built to the enlarged lines of the Lapwing. Related vessels: Lapwing (1816) Kite Fancy (1817) Racer Sprightly Nightingale (1825) Speedy (1828) Snipe (1828) Vigilant (1821) Swift (1821) Basilisk (1822) Bramble (1822) Skylark Diligence

Nothing new under the sun is there The only issue I can think of with a sled is that the stock tends to bow slightly as the side being sanded get hot. May not be a problem but....

G'day Bob, I glued some sandpaper to a board and fed it through before putting sandpaper on the drum. Interesting thought, I dismembered a laminator the other day to see if I could use the heating elements for something and I thought one of the feed rollers could be used to draw the stock out. The tilting platen makes this hard. Interesting. Physically less compact but the double taper (wedge) height adjustment would make fitting an out-take roller easier. A threaded rod parallel to the taper could be used for finer height adjustment.

More progress, It turns wood in to dust! But only just It will only just take 0.25mm (0.010") of a 135mm (5.25") wide piece of cedar (western red if it matters). I need to gear it down again, I'll try a 100mm pulley on the drum next. Height adjustment is by pushing a wedge under the platen, this will be done with a bolt or some threaded rod when finished. That and dust extraction will happen after I sort out the gearing. Sandpaper is attached to the drum with spray on adhesive and the ends are tucked in to slots cut with a hacksaw (see pic), seems to work.

More progress: The drum is round, I finished up taking it out after I marked the ends and used a plane to get it closer. Still required a lot of sanding. Final sanding will be against the platen (tilt table?) to make sure it's parallel.

Some progress. The drum is going to take some sanding, I have to take about 1mm of most of it. Motor still stalls, may need a bigger pulley on the drum. One belt handles the load.

G'Day Chris, You've inspired me! As I don't have a lathe (yet) the power plant comes first (Aldi special today): It's supposedly 150 watt but stalled when shaping the pulleys, so I will gear it to about 2:1 and see what happens. Drive belt/s will be sewing machine. One either end will give me about a 150mm sander but I'd like 200mm so maybe two belts at one end. It will also hopefully power my yet to come DIY lathe/disk sander.

No problem. It works quite well. I used it to stitch 219 images into a 1746 map of London, the final result is a 20,464 x 10,913 pixel image. This is 1/24th of the image (reduced in size) stitched from 9 images.

Microsoft ICE is a free panorama stitching program which I have often used to join scans of line drawings. The same 'rules' about scan resolution and size apply.

Technically no. One expresses a drawing that is 48 times bigger than the original ship while the other a drawing 48 times smaller. But people (including me) mix them up all the time. It doesn't really matter as you will soon notice if the drawing is 48 times bigger It should be, but you can check. 1:48 is also known as 1/4" to the foot ( 12 inches divided by 48 = 0.25 inches) so put a ruler on the scale and check it. Note, 20x0.25 = 5 so the 'ruler' should measure 5 inches long to the 20 foot mark or 1/4 inch for each 1 foot mark.

There might be more going on than you suspect. As these images may be skewed by the camera position you should check on the actual frame (you can use the corner of a piece of copy paper as a square). Also note that the dimensions shown are not to scale. In this first image the curve of the hull was drawn on the left and then mirrored to the right using my centreline. The image does not seem to be skewed. The second image is skewed so I can't do the same but the internal centreline does seem to be different to the external centreline.

In general, the best way to straighten wire is to stretch it slightly. eg. clamp one end in a vise and pull on the other end.

I do know the feeling No deck in this boat. If you're talking about the green line, think of it as a potential bulkhead actual height yet to be decided. Otherwise, the sheer is the same height at the bow and stern.

G'Day Chris, I've seen many of his vids, got hooked and watched them one after another. Will look again for specific lofting vids. Edit: Just watched Lofting the Lines Part 1, the discussion on lofting starts after 17 minutes in and it seems I my understanding of those bits was right (so far).

G'Day Mark, I freely admit I'm a newbie at ships and may be wrong. Can you elaborate on 'separately'? Maybe we can work out if we're coming at the same thing from different directions.

Lets continue: Remember those errors I mentioned? As Bruce said, you can just "ignore the differences". I chose to try to fix them. So we now have the image in the CAD program with the shape and aspect ratio corrected. First image is the 'uncorrected' version. The purple lines represent the measurements taken from the Plan (top view) and Elevation (side view) these should match the measurements in the table of offsets which I don't have. On the Stern side they were pretty close (shown in the second image) but on the Bow side at station H (looks like an 'N' on this drawing) it's slightly out while station A (in green) is too wide. If I reduce the height to bring the sheer down at station H, it will be too low at station A. This is an error in the original drawing which cannot be corrected by distorting the drawing, it needs to be redrawn. Also the rabbit is incorrect at both the bow and stern compared to the elevation drawing. This meant that I had to re-import this section of the drawing in two parts (Stern and Bow) so that I could leave the stern untouched while correcting the scale and aspect ratio of the Bow as best I can then drawing new hull lines respecting the curves where possible. The curves are a number of arcs joined by (sometimes very short) straight lines. I think one station had 5 arcs and one had 2. . Also remember that I really don't know what I'm doing. Craig.

A few examples. These are the Bountys launch. First is as downloaded, as you may see from the frame it is narrower at the top. Also the aspect ratio is wrong, the height is too short for the width. Second has been corrected in photoshop. (but I did work out the ratios in CAD first as it's more accurate). Third is many hours of mucking around in CAD with more to come. All of this is just a learning exercise so I can better understand redrawing Lapwing in CAD. Craig.

Copying your image on to graph paper and drawing the new one on to graph paper will help. Otherwise draw a grid on the original. Craig.

Provided you have both vertical and horizontal size references (objects of known height and width) you can resize the image using different multipliers for height and width. So a 1000x1000 image could be resized to a 1011x998 for example. That's the easy bit, removing distortions is harder and can be impossible. Craig.