Hi!

I'm working on a project for a theater project where I'll be building a platform with projectors hidden underneath so that I can, with the help of some mirrors, project onto the surface of the floor from below. I'll be building the platform structure out of wood and the top will likely be polycarbonate, unless anyone has suggestions for less expensive transparent materials.

I'm running into difficulty remembering how to calculate how thick the polycarbonate must be to support 100 psf. I know this is something I learned way back in statics but now I've forgotten it and the internet is proving unhelpful. Any help is much appreciated!

Thank you!

-Syd

]]>I'm working on a project for a theater project where I'll be building a platform with projectors hidden underneath so that I can, with the help of some mirrors, project onto the surface of the floor from below. I'll be building the platform structure out of wood and the top will likely be polycarbonate, unless anyone has suggestions for less expensive transparent materials.

I'm running into difficulty remembering how to calculate how thick the polycarbonate must be to support 100 psf. I know this is something I learned way back in statics but now I've forgotten it and the internet is proving unhelpful. Any help is much appreciated!

Thank you!

-Syd

I have a degree in science, but not engineering. The stack effect, I believe it's referred to, is easy to understand when there is a single stack involved; warmer air from inside a vessel moves up and out the stack as cooler air is drawn in the inlets of the vessel. Increasing the hight of the stack increases air flow out of the stack. But what happens when a second SHORTER stack is added to the top of the vessel. Will the shorter stack always act as an outlet or will it act as an inlet because it's shorter than another stack. Will it compete with the taller stack?

My scenario doesn't involve a building with floors, walls, or any means of artificially heating or cooling of interior air. Imagine the vessel is an empty tank and the air temperature inside is the vessel is always higher than ambient temps. Also assume that when the second stack is added, an equal area of inlet vents are added to the lower part of the vessel. Thanks.

]]>My scenario doesn't involve a building with floors, walls, or any means of artificially heating or cooling of interior air. Imagine the vessel is an empty tank and the air temperature inside is the vessel is always higher than ambient temps. Also assume that when the second stack is added, an equal area of inlet vents are added to the lower part of the vessel. Thanks.

Is there a formula to calculate the radius that a rod of a given radius can be bent around while staying in the elastic range? For example, if I had a rod that was 1/4" in diameter and made of HDPE (which I think has a modulus of elasticity of 0.8 GPa), how would I calculate the minimum radius the rod could be bent around while still staying in the elastic range so that it could be unwound without deformation?

]]>Hi guys,

I am working on a project for my Kin/Dyn Class and I hit a road bump in doing my analysis for my project. For the force analysis there would be a force of 80 pounds from the counterweight. So I drew my arrow for that. Do I need to consider link three first or just do the graphical force analysis on link 2. The height of the trebuchet is 2.5ft. Arm: 3.4ft. Weight Link: 1ft

I am working on a project for my Kin/Dyn Class and I hit a road bump in doing my analysis for my project. For the force analysis there would be a force of 80 pounds from the counterweight. So I drew my arrow for that. Do I need to consider link three first or just do the graphical force analysis on link 2. The height of the trebuchet is 2.5ft. Arm: 3.4ft. Weight Link: 1ft

Hi there

I need to calculate motor speed and reduction on a drive wheel.

the wheel is 2" diameter and is pulling a wire that is pinched between it and another roller. I'll need 100lbs of pull on the wire. I'll need to pick a dc motor and reducer to get this and we already got it wrong once...

]]>I need to calculate motor speed and reduction on a drive wheel.

the wheel is 2" diameter and is pulling a wire that is pinched between it and another roller. I'll need 100lbs of pull on the wire. I'll need to pick a dc motor and reducer to get this and we already got it wrong once...

Hi all,

I need help with a Gear Train described below. A rough sketch is attached.

I have a Round Plate above which there is a 88 Tooth Gear (Gear A). Both have their own drive and the ratio is 1:4. For every 1 turn of the plate, the Gear A rotates 4 times. They both rotate in the same clockwise direction.

On the plate is fixed a Gear B which meshes with the 88 Tooth Gear A.

I want it such that for every 1 rotation of the Plate, the Gear B rotates 18 times.

I am unable to figure out the no. of Teeth for Gear B, and would be grateful for any help with the formula/calculation.

If required, I can change the ratio between the Plate and the Gear A and/or the No. of Teeth on Gear A.

I need help with a Gear Train described below. A rough sketch is attached.

I have a Round Plate above which there is a 88 Tooth Gear (Gear A). Both have their own drive and the ratio is 1:4. For every 1 turn of the plate, the Gear A rotates 4 times. They both rotate in the same clockwise direction.

On the plate is fixed a Gear B which meshes with the 88 Tooth Gear A.

I want it such that for every 1 rotation of the Plate, the Gear B rotates 18 times.

I am unable to figure out the no. of Teeth for Gear B, and would be grateful for any help with the formula/calculation.

If required, I can change the ratio between the Plate and the Gear A and/or the No. of Teeth on Gear A.

I am currently working on my undergraduate thesis - it's focused on the design and upgrade of a filament winding machine (both hardware and software) that was designed and built in-house at my university. One of the tasks that I need to do is to update the controller code to allow the machine to be able to wind in helical patterns and dome shapes. However, I'm having a really hard time finding relevant literature surrounding the mathematics of these topics. I have discussed this issue with my supervisor and he suggested that I try to find some open-source filament winding control software and reverse engineer it if possible. However, I've had no luck with finding any such software. My question then is, where should I be looking to find the resources/literature on the topic of helical winding and winding over dome shapes? Relevant books? Articles? Reports? I would also like to ask for any advice from industry experts with regards to this topic. Thanks for your time and help.

]]>