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getting your profile

PostPosted: Tue Sep 09, 2008 12:34 pm
by rhltechie
Hi All,

I am still not sure I understand the process of getting the profile of the TD. I am following the GenBen plans but i am uncertain of this whole beam compass thing. Is there an easier way to do so? What should I use to cut my template so that I do not waste the expensive plywood if i do screw up? I think i have seen a few cardboard cut outs here...is that the best thing to do?

thanks,

mandy

Re: getting your profile

PostPosted: Tue Sep 09, 2008 12:53 pm
by del
rhltechie wrote:Hi All,

I am still not sure I understand the process of getting the profile of the TD. I am following the GenBen plans but i am uncertain of this whole beam compass thing. Is there an easier way to do so? What should I use to cut my template so that I do not waste the expensive plywood if i do screw up? I think i have seen a few cardboard cut outs here...is that the best thing to do?

thanks,

mandy
Hi Mandy there are several ways to draw out a profile. http://www.angib.pwp.blueyonder.co.uk/teardrop/Profile-Generic-Benroy.pdf Look at the last pages of Andrews pdf. I drew a grid and marked the points with finish nails. Next a used a bendable 8' ruler to draw a line to draw (many people use wood).
Image

hope this helps del

PostPosted: Tue Sep 09, 2008 6:13 pm
by cdfnchico
Mandy,
The whole compass thing on the Gen Ben was actually pretty easy....cut them to length, 19 & 48, with an inch or so extra so you can screw it down. The length from the screw to the center of the hole you drill for the pencil should be the neccesary length. Mark the intersection as labeled on the plans...screw the board down loosely at the intersection, place the pencil in the hole and draw the arch...don't stress it, you're only marking a couple corners... it only took us 10 minutes. And if we can do it...you can!

PostPosted: Tue Sep 09, 2008 6:20 pm
by rhltechie
don't stress it


hehe...i think you hit it on the head! i always stress it until i do it!

thanks for your reply...its nice to hear its as hard as i am making it out to be :)

PostPosted: Tue Sep 09, 2008 7:21 pm
by asianflava
If you are concerned about making that first cut on the "Good Stuff", make a template out of something cheap like masonite. You can draw the profile, cut it out, and massage the profile to your liking.

If you decide you don't like it at all, you didn't spend that much money. If you do find something you like, you can use the masonite as a pattern to make the sides.

PostPosted: Tue Sep 09, 2008 7:23 pm
by rhltechie
hmmm..masonite. i have never really heard of the stuff. its just really cheap pressed board?

PostPosted: Tue Sep 09, 2008 7:25 pm
by Ralf
The cheapest 4x8 paneling you can find at the big box lumber store makes a good 1st pattern. If you are going bigger than 4x8, firing strips and short drywall screws will join the sheets. Cut out with jigsaw. Before you commit set the pattern up on some milk crates (or the trailer) and look at the lines (shape) IT SHOULD PLEASE THE EYE. A belt sander can be used freehand to "fair" the lines. (that's a boat builders term).

Sometimes, compass drawn arcs need a little tweaking to look good to the eye. If arcs of different radius meet, these areas usually need work. A long thin strip of wood and a few nails, bricks or clamps help fair the lines. An 8 foot piece of wooden shoe molding or similar thin molding will bend to a fair curve.

PostPosted: Tue Sep 09, 2008 7:39 pm
by Hoosier Greg
I too made a temp plate from masonite..

Once I had the profile in my mind I used a garden hose that I had seen some one on the board using to draw their profile.

With a garden hose you can lay out a profile step back to see if it is as you envisioned it. If not, you can move any part that does not look right. Then with a pencil or a magic marker, draw along the outer part of the hose. Very simple..
Greg.

PostPosted: Tue Sep 09, 2008 11:32 pm
by asianflava
rhltechie wrote:hmmm..masonite. i have never really heard of the stuff. its just really cheap pressed board?


It isn't even that, it's more like compressed paper. It is the same stuff that pegboard is made off.

I actually used 1/4 ply for my pattern. I had it on hand for something else. I think I was going to use it for my side walls until I changed my mind and went with 1/8in.

PostPosted: Wed Sep 10, 2008 11:53 am
by McBrew
Mandy, at least it sounds like you don't need to use string to draw a parabola... my Cub uses four different parabolic curves!

Image

PostPosted: Wed Sep 10, 2008 12:27 pm
by Toytaco2
We made our profile from masonite as already suggested. Since the profile was bigger than 4x8 we had to piece it together. We then used masking tape to mark off the location of internal wall framing, doors, cabinets, etc. It was really useful since you could lay it down on the saw horses and build your wall framing on top of it - sort of like having a detailed pattern to follow. The curves were marked using the beam compass approach. It only took about 10 minutes for that part since we had already determined the arcs by drawing the profile to scale on graph paper.

Image

PostPosted: Wed Sep 10, 2008 12:59 pm
by Mary K
Image

I made a compass out of a 1x2 scrap. Put a screw in one end and pencil hole 19" (Gen Benroy front radius) from the screw. I placed the screw point 19" from the top and side for the center point , and trace out the radius with the pencil.

Same goes for the Hatch radius, make a compass for the 48" and reuse the 19" compass.

Cut one side wall and use it as a template for the other. A belt sander comes in handy at this point. :D

Mk

PostPosted: Wed Sep 10, 2008 6:59 pm
by cdfnchico
We too, used masonite...about $12, to create our template. When we had sanded it and had a "perfect' template, we used it with a router and a top bearing bit, to cut the actual sides...slick!

PostPosted: Wed Sep 10, 2008 7:54 pm
by Jst83
Couple of big pieces of cardboard taped together, then use a pencil so you can erase and adjust as needed. No real approach just draw a big curved shape and stand back and see how you like it.
Pretty cheap but it worked for me.