ME Project - Stair Climbing Mechanism

It depends on the specifics, but in general fast-rotating gears will experience low torque and can maybe be made of plastics, whereas slow-turning gears have greater torque and are usually made of metals. You need to check the stresses on each gear in the train, and select a material that can handle at least as much.

generally , during designing process we considered gear material as cast steel (ie low speed ) but we also need to consider weight of entire mechanism in order to overcome a series of stairs( approximately 8 to 10) as we also have to accomodate platform , a motor , 4 wheels with 7 gears on each wheel....... can you suggest in specific which material to select ....... speed will be 5 km/hr

To understand this further, I would need a drawing or sketch.

Right now i cant give u sketch of entire mechanism, but i can provide u with sketch of wheel. I need to select suitable material for gears firstly to balance weight and secondly it should not fail as increase in weight will result an increase in load on motor due to which mechanism might get stuck while climbing and fall....... so please help

Thanks! Interesting mechanism. Instinctively I'm thinking of all metals, but maybe two different types--say steel for the 4 larger gears and bronze for the smaller. Maybe there are even oil-impregnated gears?

Are you thinking:

One motor for each wheel?

One motor for each axle?

One motor drives all four?

Will this be battery power, or drag a cord?

Can you tell us approximate diameter of the individual tires in the wheel?

two motors one for maintaining platform horizontal

secondly, for mechanism

single motor,for four wheels, ( rear drive) transmitting to front using chain drive

Hi,

steel-POM is an excellent combination if load is low,

fiber reinforced phenolic resin (both sides) is suitable for higher load,

PEEK will be too expensive,

aluminum, hard anodised and lubricated with water, oil or grease (6061 or 6068 for medium and 7075 for high strength) will be a good, lightweight and economic choice,

steel - ok- any of classical high strength alloys, but try off-the shelf supply.

RHABE

Hi Brendan,

Please clarify if you plan to carry people who can not climb the stair case?. In that case I had seen a brouchre of one of the mfr. who had fixed rack below the handrails and a chair on which drive meachnism with rotating pinon is fixed.

If you are designing a robo to climb the staircase then you should select alloy steel DIN 16MnCr5 steel which is used in hoist gear boxes. This material is suitable for case hardening and hardness of 56 Hrc. can be achived for both gear and pionons.

Suresh Sharma.

Not enough information. How about estimated weight of the mechanism; Gross weight of the intended load; purpose; safety considerations or limitations such as OSHA requirements; variable of fixed stair heights, etc. etc

sir,

weight of entire mechanism will be approximately 30 kg, including self weight (i.e. considering motor , gears and platform).

as we are considering a prototype, so at present purpose will be transporting load

speed is assumed to be 5 km/ hr, for which high torque low speed motor will be used.

as we are considering a series of steps, safety criteria is that the mechanism doesnt get stuck or fall while climbing for which weight needs to be maintained within limit.

can you help in selecting material for gear so that it compromises for weigth and at same time does not fail

at same time we will be modifying the mechanism (ie maintaining platform horizontal) which currently is not a issue as we found a method

Brendan4's problem is perhaps surprisingly challenging. As the 3 outer green wheels engage the stairway, various other components, such as the spiders connecting them, and the drive mechanism to the upper set of wheels, must keep from scraping against the stair nosings as the whole assembly ascends. Then, if descent is also contemplated, there is yet another set of issues.

I think I have seen this 3-wheel idea on some stair-ready hand trucks, and have even played around with a notion or two, without coming to a satisfactory scheme so far.

Please keep us all posted on this!

i jus have a doubt regarding this mechanism weather effective steering is possible in this case .I think the steering leads to the drag of the wheel

can u help me with this