I’m a hobbyist and I’ve got this idea that, to me, seems pretty simple. I just can’t seem to find the parts because I don’t know what they’re called. I’m pretty sure my idea is feasible, because I got the inspiration from a similar implementation on my motorcycle.
Basically, I want to connect two shafts (spindles? Axles?) using two cables so that rotating one makes the other rotate as well. I’ll use two cables to wind them around the shafts in opposite directions so that twisting the shaft clockwise will provide slack on one cable and simultaneously increase tension on the other cable; twisting the shaft counterclockwise will, obviously, reverse those effects. Ideally, I’ll be using shafts of different diameters so that twisting the larger shaft will make the smaller shaft rotate more.
I can see a similar operation in place on my motorcycle: There are two cables attached to my twist-throttle and they attach to a cam on the engine. Twist the throttle counterclockwise and the fuel supply is increased; release the throttle and springs on the throttle and the engine reverse the impact; twist the throttle clockwise and the cables reduce the fuel supply even faster.
So I need cables (or perhaps wire rope), obvously. I need some kind of collar to attach the cables to and put around the shafts – but I don’t know what that’s called. It is not a “pulley” or “sheave” because those are designed to rotate (relatively) freely and don’t have notches or slots for catching the button-end of the cable.
This is driving me nuts and web searches are not helpful when I’m using the wrong terms. I think I could find a parts supplier if I can provide the right search terms. Better yet, if you know of a parts supplier (probably not McMaster Carr, 'cause I’ve searched there already), please provide useful names (url not necessary).
Garage doors use this system also to wind the cables around the cross shaft. Those particular versions also change diameters as they wind. Those are called pulley cable sheaves or cable drums.
I think it’s just a type of pulley. Systems like you describe are commonly used with Bowden cables–those cables often used for bicycle brakes and gear shift lines that consist of a cable inside a stiff but flexible sheath.
And as best I can tell, when these cables are used for circular endpoints, they’re just called pulleys. For example:
It has what they call an “antagonistically wound pulley”, which basically just means they have two cables wound in opposite directions (and also different diameters, presumably giving different torque in each direction.
Sounds like “cable pulley” is a good term. Sadly, so many search engines have gotten away from following your request explicitly and will also show you “related” searches, that I suspect the vast number of hits for “pulley” will utterly overwhelm the hits for “cable pulley”.
You can still force e.g. Google to search for multi-word matches and only multi-word matches, but IIRC it’s not as simple as “word1 word2”.
Not clear what you are doing. Can you describe what you are making and it’s purpose in more detail? It sounds like you want to pull on something when you rotate a shaft in one direction, and release that and pull on something else when it rotates the other direction. This can be easily done with a single lever which activates two control arms (or cables) in opposite directions. Attaching to the lever at different distances from the pivot point allows different action lengths for each direction.
Mech Engineer here. I agree with the other that what you are looking for is probably a type of cable sheave or cable pulley, as best as I can tell from your description of what you are trying to do. If what you need exists, McMaster-Carr or Grainger Supply sells it. If neither one has it, you’ll probably have to design and make it yourself. So try searching those two sites.
The ultimate goal is a rolling cart for a wok station – basically a pseudo-Chinese variation of a rolling barbecue grill – based on a design I saw on YouTube. A wok stove for a Chinese restaurant will have two or three burner rings and gas flow is controlled by either knobs at hip-level that are controlled by the cook’s fingers or levers at ground-level which the cook slides left or right with his/her toe.
[There are a couple threads around Cafe Society in which I contributed by expounding on the virtues and usage of a wok. I’ll reiterate here that a proper wok is typically heated to about 700 or 800 degrees and cooking is often done very fast and therefore requires both hands and constant attention, including quickly changing the heat levels in the middle of some recipes.]
I can’t afford a professional-grade wok stove, nor do I have room to store such a thing when I’m not using it. Instead I bought a double-ring wok burner [not this one, but kind-of like it: Auto ignition dual ring burner - BBQs R Us] that I’ll set into a hole cut into a rolling cart (so I will also have some work space for setting ingredients before I throw them into the wok) which I’ll be able to easily roll into the garage to protect it from the elements. The device itself is made with a knob on a shaft that controls the gas valve. I want to control it with my foot because my hands will be preoccupied. That’s where I want to employ the idea of controlling the shaft rotation via cables, just like the throttle cables on my motorcycle.
I can probably salvage a motorcycle throttle and mount it on a 7/8" pipe (same diameter as typical motorcycle handlebars) with a metal plate screwed to the hand grip so I can operate it with my foot. What I need is the piece to replace (or sit behind) the knob on the burner that will connect to the other end of the twin throttle cables and grip a shaft that is probably about 1/4" diameter. Again, I don’t know what that kind of thing is called. It’s almost like a stop-collar for a drill-bit, with a special notch cut on the edge to catch the button on the end of the cable and a groove cut along the side to accept a wrapping of cable. Another way to think of it is like a pulley sheave with a notch cut for the cable-ends and a set screw to lock it to the shaft (rather than bearings or sliders that let it rotate on the shaft). Or imagine scaling down the Cable-Drums, that MixDenny suggested, to about 1/20th the size.
When I look up variants of “cable and pulley” I get block-and-tackle systems and replacement parts for gym equipment. When I look up “shaft and cam” I get mechanical cam-and-follower systems – which are pretty cool, but not what I’m looking for – often for combustion engines. When I look up “shaft collar” I get things like drill-bit stop-collars. But SOMEbody must make this kind of thing for use in building cable-controlled mechanical devices and it’s gotta have a specific name, right?
So a lever driven burner throttle?
How much of a rotation does the knob need to travel from idle to blast?
How about bicycle shifter / derailleur cables? Supplies should be easier to find and work with the motorcycle stuff.
For really fine control, a drummers’ kick pedal would be sweet.
Yeah…a lever-driven burner throttle.
I’ll be using propane outside, so I was just going to call it a “gas pedal.”
The existing control knob seems to make 1 full turn from clicking off to full-blast plus a notch to make the piezoelectric thing click and ignite the gas.
I’m not having trouble finding cables. There are bicycle and motorcycle shops that can provide those. I’m having trouble finding the collar-thingy to attach to a shaft.
I really LIKE your idea about the bass drum pedal!
It’s already spring-loaded and the chain-driven models make a shaft twist, so I’d attach two of my (whatever they’re called) around that shaft and the other two (whatever they’re called) around the burner’s gas valve control shaft. The inner and outer circumferences will undoubtedly be different between the two pairs.
Not quite, I guess.
I looked up “cable couplings” and saw neat devices, but not what I need.
That did lead me to clarify that I’m planning to use pull-cables. That seemed to narrow my results down to cable (and sheathed cable) manufacturers, but their sites didn’t have the little collar thingy I’m looking for.
After a tremendous amount of searching and getting lost down rabbit-holes…
LSLguy: You are the most correct from the answers above. The device is called a DRIVE pulley, which is affixed to a shaft for the transmission of power to or from that shaft. This is in contrast to an idler pulley, which spins freely and is quite common in block & tackle systems and such.
Dorjan: You are also correct. When I finally got the product category and term correct, I found what I need on McMaster-Carr: A “round belt pulley,” which I can configure to dimensions that.
I think I’ll still look for that kick pedal. Then I can measure that “winch” shaft to get the bore size and go from there.
This would be a better way to do it. Positive action on the pulleys from the cog belts so no slippage. Look for belt and pulleys for 3D printer kits. I have a set of these parts I got on Amazon similar to this one. Didn’t cost much compared to McMaster Carr and other suppliers.
If you don’t need much force, just get a couple of inkjet printers from local garage sales or thrift stores and cannibalize forth. Might be a way to prototype what you need.
