pulley sizes for better torque

[1637]

so i made my dry washer ruffles and bellows 5 i.nches wider.but with the extra dirt i need put torque and speed.would it be better to made the small pulley bigger or that big pulley smaller.i know the ratios would be the same,but i wonder if one would make more torque,
just thinking out loud, thanks brad

 

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[firemanphob]

I don't think you can gain torque and speed both with a pulley change. you can get more torque with less speed or more speed with less torque.

 

[Nitric]

Think of it like a 10 speed or a mountain bike. .... The smaller the pulley on whatever your running is harder on the motor but gives more speed. If you make the pulley bigger on what you are driving, you lose speed but it makes it easier on your motor. The opposite applies if your talking about the Motor pulley....Basically...

If you want more speed AND more torque? Then you need a stronger or higher RPM motor. Either more power or RPM's you can work either of those, but you can only get so much speed and torque from a motor no matter what you do with gearing or pulley's..

I know nothing about a drywasher. Just a little about trying to get power ,speed or both. I also know there are fancy words and formulas to tell you exactly what you need...But I never remember that stuff...I just remember the basic idea....

 

[Icewing]

Is the drive motor AC or DC?

I ask because most DC motors are pretty versatile in that they can operate on a wide range of power, rather than just on/off.

You might be able to add another battery and a rheostat to increase your power and make the speed variable (controllable).

 

[Nitric]

ohh..I forgot to add in something....Unless it has a flywheel(big heavy one)...You can change some things with the weight of the flywheel get more power(kind of, depends) and keep same motor and speed, then that gets into some other stuff, but it may help?

 

[1637]

12 volt automotive?? no flywheel

 

[Nitric]

12 volt automotive?? no flywheel

Throw more Amps to the motor if it will allow! You may be able to double up on batteries keeping it 12v and get what you need. Bigger is better! Sometimes, even wiring can hold it back but you would probably see things getting real hot(like wires and connectors) when loaded.

A place I worked at would even add Capacitors to help with uneven(times of being bogged down) loads on motors and batteries. This Is something I know little about..But may give you a direction, or maybe someone reading understands that type of stuff, it may not even apply here, just an out loud thought.

 

[Icewing]

12 volt automotive?? no flywheel

Try a bigger battery such as a 1,000 CA truck battery.

 

[1637]

thanks for all the input,i use a truck batt,900 plus amps,i have a 2in and a 14 in pulley now .its 7to1.iam going to try a 2in by
12in,6 to 1

 

[Nitric]

thanks for all the input,i use a truck batt,900 plus amps,i have a 2in and a 14 in pulley now .its 7to1.iam going to try a 2in by
12in,6 to 1

Your doing the opposite of what your looking for if your looking for more torque. It's going to bog down faster, unless your thinking the added speed will take it out, but with no type of flywheel, I'm not sure that would work.

Maybe....Look for the biggest, baddest, heaviest 12 or 14in pulley you can find. That may help. I've seen big heavy pulley's about that size on old air compressors.



Edited..
added....I may be all wrong...When I was thinking of this I was thinking of something that crushes rock too(was a little confused when I saw 12v and no flywheel.Now I know why). And that's where I was stuck with the whole "torque" thing. I was thinking of rocks going through and being crushed, then working through riffles. Your extra speed may do what you need...I'll have to go look at a drywasher to see what's going on and how it works exactly.

If it's just running a shaker and a fan/blower? More speed is maybe what you need? Maybe even playing with the shaker mech to get what you need depending on design. I guess, I should learn about the equipment before running my mouth. I do understand pulley's, just not the equipment design that your working with....Either way..It was a fun problem to think about for a few minutes.

 

[1637]

it uses bellows and angle to move the dirt though the riffles

 

[Nitric]

it uses bellows and angle to move the dirt though the riffles

I went searching the net to look at designs trying to get a better idea of how they work. If you crank up your speed is there a chance of losing fine gold because of increased air flow?

I'm still looking ...trying to find one that moves dirt with angle and not a shaker. I think I saw a huge version of what your saying in a video a while back. It had a grate type thing made out of angle iron that went up and down and forward and back, to move dirt down a sluice, but it was something like 10ft wide and real long.

 

[1637]

not trying to up the speed,just trying to get back to the speed it had before i made it 5 inches wider.its allot more dirt to move.

 

[arizau]

I'm thinking you somehow altered the unit's original "stroke" geometry/timing when you modified it. Lengthening or making the "new" bellows taller could be the cause of your problem(?). If you did you probably also had to adjust whatever lifts your bellows to give it full motion maybe resulting in less strokes/minute.

 

[Nitric]

not trying to up the speed,just trying to get back to the speed it had before i made it 5 inches wider.its allot more dirt to move.

You can't get that(speed back) without changing Power(fuel/amps) to the motor if it will handle it or going with a bigger motor. There is only so much power(work) you can get out of a motor(at the motor) no matter what the gearing or pulley's are doing. I don't know your design but if added weight is the problem, then you need more power(ability to produce work?) somewhere, before or at the motor(amps/fuel, whether gas or electric). Changing the ratio won't bring your speed back with increased load(work?) if you don't have the power(at or before motor/fuel) to keep it now. You may be able to play with levers and cams on different parts of the machine to help too?

I'm horrible with words and trying to explain. I can see and understand it, but trying to get it out is all different. So, above may make no sense, and ended up a rambling mess since I can't remember the correct terms. Basically..Going 6 to 1 isn't going to give you what you want.

It all comes back to a 10 speed bike. Your the motor, your only strong enough or fast enough to over come the hill, no matter what your gearing is. To get up the hill pulling another person in a wagon, you need to be stronger, if you want to maintain the same speed that you had when you were by yourself before the wagon was added. The major difference with a bike is the ability to change gears, but the idea is still the same. You can increase speed or torque, but you can't increase both with the same motor or fuel, can't have both, people bang their heads off walls trying to overcome this in the car world, and it's not possible using the same motor and fuel.

 

[arizau]

As an after thought....just putting a smaller sheave on the bellows drive will increase it's rotational speed unless the motor is, in fact, under powered.

 

[1637]

so ,after thinking about it all nite,again,i when and got a fish scale.the new bellow and cloth weights more when i pole it.so iam going to put a counter weight on it though a cable or linkage,iam going to take about half the weight off this way.
why?i guess because i can.
brad

 

[russau]

Hope this will help clear up a few things. http://www.blocklayer.com/pully-belteng.aspx

 

[Nitric]

Hope this will help clear up a few things. http://www.blocklayer.com/pully-belteng.aspx

That is a cool link...I went digging around in there and it tells you just about anything!!