Wooden Desktop Trebuchet

Step 2 Dimensions

Time to start cutting up all of that wood. We're going to need pieces of the following dimensions:

2 x 6" Long frame side rails - Part A
2 x 3" Short frame sides - Part B
1 x 7" Frame crossmember - Part C
2 x 4.5" Frame extension rails - Part D
2 x 4.75" Uprights - Part E
4 x ~3.5" Long diagonal supports - Part F
2 x 2.25" Short diagonal supports - Part G
4 x ~1" Launch ramp support blocks - Part H
1 x 7.5" Upper Arm
2 x 2.25" Lower Arms

Parts D, F, and G need 45 degree miters cut on each end as shown in the picture. The length measurements are, of course, along the long side.

As for the long diagonal supports (Part F), you'll need to finely adjust the length of these in order to get them to fit nicely. Check the fourth image in step six to see what I mean. The given length of 3 1/2" should get you pretty close depending on how well you cut the frame extension rails.

The launch ramp supports (Part H) are just little bits of scrap that are angled to make a trough with craft sticks. A 45 degree cut isn't quite long enough to attractively cradle a jumbo craft stick so the angle on those is shallower. I just eyeballed it and got something that looked nice. Putting a protractor on it shows it to be about 35 degrees or so. If you don't feel like going through the trouble, you could just glue a couple of craft sticks flat on the frame to make a plank bottom and it'll work fine but won't be quite as pretty and you'll have a little harder time lining up consistent shots.

Comments

[FallenAngels]

it looks 3 inches to me they bigger than the lower arms which are 2.25" and smaller than part f

[torroid]

You may want to double check the lengths that you list. They don't match your pictures. For example, part B looks longer than the 3" your spec says it should be.