# Search results

1. ### Need help identifying cog

Xxx Xxx xxx xxx
2. ### Differential Question

Hi. I have a quick question about a differential made up of 4 bevel gears. Say there are two axles which go into either side of the differential as shown in the diagram. Both axles have a pin mounted at the end to track its position radially, initially both pins point up...
3. ### Translating Motion - Which is the most efficient?

Hi! Thank you, it took me a while to find them. Im looking to get around 2000-3000rpm
4. ### Translating Motion - Which is the most efficient?

Hi. I need some wisdom! Here is my problem. I want to make an air powered engine. This isnt a problem, I have plans for this. However, I want to put my own twist on the engine. I want it to be a axial engine, so the axle is in the same plane as the cylinders. The importance factor is...
5. ### What mechanism is this?

Ah I see, that's quite interesting actually. Do you think a circular cam with a wave cut into its circumference and then attached to the cylinders via rollers would also be viable? It would mean I wouldnt have to use springs to push the pistons back down.
6. ### What mechanism is this?

Hi, i know what engine it is, im after the mechanism that converts the reciprocating motion into the rotational movement of the flywheel at the top. I dont think a crank and slider mechanism is what is used, since the reciprocation motion is on the y axis, and the rotation movement is pivoting...
7. ### What mechanism is this?

Its worth noting that the reciprocating motion is the powered motion and the rotational movement is the output
8. ### What mechanism is this?

Hi, I was just wondering what kind of mechanism is used in this video It converts the up and down movement into rotational movement, and it all seems very compact and smooth. James
9. ### Cylinder Linkup Confusion

Ok, I understand all of that. However what happens when the length of the pivoting connecting rod is different between piston A and piston B? Say piston A has a length of 10 cm and piston B has a length of 5cm?
10. ### Cylinder Linkup Confusion

Hi, Thank you for the reply. That makes sense, but when I consider the length of the shaft that it pivoted, I still am I bit confused. After thinking about this for a little bit, I think the best way I can explain it is the following: In my first image, will the travel of the cylinder head...
11. ### Cylinder Linkup Confusion

Hi, I have a question about one of the engines im looking at for a project. I am linking two cylinders together. One is a cylinder with a pivoting shaft (piston A), the other piston has a cylinder with a fixed axle so it can only move in and out (piston B). To allow piston be to move with the...
12. ### Working out Cam dimensions

Hi, Im trying to work out the dimensions of the offset on a cam for a project. I know the travel of rod c, as well as the length of the connecting rod b, but im not sure what the lenth of dimension a should be. I know this is probably simple maths (just pythagoras?) but I need to make sure I...
13. ### Simple Question about engine timing

Hi. Its a StirlingEngine. The offset between the crank pin and the centre axle is .625 inches (the travel of the piston is 1.25 inches) Hope the exert below from a website can clarify:
14. ### Simple Question about engine timing

Im really stuck here, I asked my friend and he said this: Can I get a second opinion on this to make sure I dont do it wrong.
15. ### Simple Question about engine timing

Just to also run this past you, when it says a 90 degree offset, I guess that is the same as saying 1/4 offset?
16. ### Simple Question about engine timing

Ah see I would have been more inclined to say it still needed a 90degree offset because the position of the cylinder around the circumference doesn't seem to have an affect on the pistons phase.
17. ### Simple Question about engine timing

Urgh im sorry that doesnt make any sense. Ive edited it now, I hope it makes more sense. Its basically a 90 deg phase angle between the two pistons
18. ### Simple Question about engine timing

Im looking at designs for a engine, but im giving myself a headache over something which is probably incredibly obvious. Ill explain it as simply as I can in text and ive drawn a (terrible) paint image to help explain it a bit better. There are two cylinders. One cylinder needs to have its...
19. ### Light defration - How can I distribute the light evenly

Hi, Im making a light at home, but I have a problem with it. The luxeon star being used to supply the light creates a large bright spot on the top lens, and leaves the rest of the lens mcuh darker. I now need to make a lens to sit over the luxeon star which will defract the light so it lights...
20. ### Electrical Safety - Shocks - Model Answer?

Ill find the design tomorrow in the exam but it will be to late then :P. Should i just look up what these safety standards entail then?
21. ### Electrical Safety - Shocks - Model Answer?

Thank you for the reply. The question is worth 15 marks through, despite what i already know and what you have told me do you really think that will be enough?
22. ### Revive Resistance - Series & Parrallel

Homework Statement Two resistors, when conected in series have a total resistance of 12.9KOhms, and when connected in parallel a combined resistance of 2.988KOhms. Derive the value of the individual resistors. Homework Equations R = R1+R2 ---Series 1/R = 1/R1 + 1/R2 The Attempt at...
23. ### Electrical Safety - Shocks - Model Answer?

Homework Statement a) You have been asked to design a convector heater (electric radiator) which has a metal body. Detail an appropriate method of preventing electric shock for users of this product, and show how such a protection strategy could be implemented in your design. (15) b)...
24. ### Mech - Girder Section - Picture included

Ok, so i take moments but i have to use the distance with respect to the letters, im not given any distances. Can i still do it like that?
25. ### Mech Help - Moment & Friction

Force F as in the friction force on the wheel or the force pushing the trolley? I really appreciate your help Doc Al, but im having a hard time understanding the process i have to go through to get the rigth answer. Can you possibly go into a little more detail so i am able to understand?
26. ### Mech Help - Moment & Friction

Since the weight is central, does that mean the weight on point A and point B will be equal? If this is the case, that means there is a reaction force of 250N at point B. Is that correct?
27. ### Mech Help - Moment & Friction

Am i not accounting for the weight at B by finding the moment of the weight force? If im doing something wrong can you please set me straight, its the first question on this past exam paper and its driving me nuts.
28. ### Mech - Girder Section - Picture included

Homework Statement http://img132.imageshack.us/img132/8958/mechanicsgv3.jpg [Broken] The Attempt at a Solution (i) Is the weight balanced on both sides in a situation like this, in which case it would be: Or are the weights not equal and infact im meant to work it out with...
29. ### Mech Help - Moment & Friction

Hi, thank you for confirming (i) is correct. Im still a little confused about (ii). It gives me a coefficient of friction value of 0.5 for the wheel. I know: F = Coefficient of friction X Resultant F = 0.5 x 500 F = 250N = Friction force acting in the opposite direction of the force...
30. ### Mech Help - Moment & Friction

Homework Statement http://img237.imageshack.us/img237/7580/mechhelpui7.jpg [Broken] 2. The attempt at a solution (i) Moment of F = 70 x 800 = 56000 Moment of weight = 500 x 270 = 135000 Therefore the trolley remains at rest. Is this right? (ii) Can you help me...