Official Luthiers Forum!

Hi,

I'm making an acrylic outside mold template which later would be used in routing for an outside mold. My problem is that the curved part, that I did it by hand with a sandpaper wrapped on a round wood block, didn't perfectly fit with my half body template.

I've seen some made it with a drill press and robo sanders but I haven't got those stuff yet. What I'm considering is making a smaller half template with the curved line staying 1/2" short from that of my actual half body template by routing with a 1/2" rabbeting bit while keeping the center straight line flush to the actual body template's centerline. Next, I would use this smaller template as a guide in routing for an outside mold with a 1/2" flush trimming bit.

I think this might work but not so sure, so I'd like to have some opinions here before doing. How do you guys think? Thank you.

               ParamesB38972.5398032407

I am not sure wich way you are short in my mind I think I follow. but a picture would help. Presonaly I would make a form that does match as you want instead of trying to compensate. I am not sure why or how you would have got 1/2" to the side off even by hand. If you can post a picture I may be able to give more insight.

The absolute best and most accurate way to make any pattern is to use a
router template bit (flush cut bit). You will want to get some inexpensive
material (wood, mdf, particle board) about 1/8" thick. Draw your pattern
on this and then cut close to the line. Then sand the pattern with a
sanding block to the exact shape. Because it is then it is very easy to
sand to the exact shape. Don't use anything thicker than 1/8" or it will
make this part more difficult than it needs to be. Then use a router
template bit to transfer that first pattern to another material of better and
more stable quality - lexan, acrylic or furniture grade plywood. You then
will have a PERFECT template.

This is standard practice throughout the fine woodworking industry and
for good reason - it is fast, easy, and very accurate.

Best of luck,
SimonSimonF38972.8921180556

Thanks for the input. I couldn't sand to get the smooth exact shape so I've come up with this routing idea.

Michael,
What I'm going to do is making a smaller half body acrylic template with the curved line stay short from my actual half body template while keeping the centerline flush to the actual template.

With this half body template that only its curve stays short, I'd place it on another acrylic sheet that'd be used as my outside mold template and rout along the curve with a flush trim router bit. In this way, the smaller curve from the smaller half body template is now compensated back to the actual curve in my outside mold template by the diameter of my flush trim bit, in this case 1/2". The result is I could get the outside template whose curve's perfect fit to my actual half body template.

Do you see this idea might work? Thanks.

I know this isn't a robo sander, but.....

SanderAoibeann38972.9564467593

_________________
Aoibeann