Thanks to Mike's info I was able to download the assembly instructions. And I have done more than reinforce or stiffen the beams. I Iaminated strips of scrap card stock so that all the beams and the base are completely solid. They now weigh more than they would have if made from solid wooden parts I olny have to laminate the wheels to appropriate thickness and add metal colored rims. And add short lengths of bamboo skewer to reinforce the beam joints
Your mechanism photos should be a big help. they are much better than the assembly diagrams. With the extra weight and density of the beams I should be able to double or triple the number of elastic bands. My goal is to fire a piece of rubber eraser the full 70 foot inside length of my house! With a 16 foot vaulted ceiling I might make it if I can clear the 9 foot high built in cabinet down in the kitchen end. Wildman ----- Original Message ----- From: DougT To: PaperModels GoogleGroups Sent: Monday, August 02, 2010 5:33 AM Subject: [Papermodels II 42650] Re: still finding a catapult I built that catapult a while back. The original model was made with some thick card so when you make it with cardstock that can be sent through most printers you will need to reenforce some areas so they can withstand the forces exerted on them. The Bumper Beam needs some internal support and stiffening so it can withstand the force of the Throwing Arm when it hits it. The Anchor Beam needs reenforcing so it can withstand the force of the elastic band used for the motive force. The bottom end of the Throwing Arm also needsw reenforcing so it can withstand the force of the elastic band. I put some internal supports made of card in the shape of an I-beam in those areas, and stiffened the parts using some CA glue. Here are some photos of some critical areas. They might help you in figuring out the motive hookup -- You received this message because you are subscribed to the Google Groups "Papermodels II" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/papermodels?hl=en.
