planetary gear tension tool

[critmass235]

After trying spring tension tools and having only limited success I wanted to make something that
make tension easier. The problem with spring is u lose feedback. So I thought a new way would be to increase
feedback. The only way if been able to think of is gear reduction. I've looked to see if any one else has tried this
( was hoping falle safe had). Planetary gears would word if the input was the sun gear and the output was the
planet carrier ( you get the most gear reduction that way) using your middle finger to hold the ring gear still
and your thumb and pointer turn a wider extruded handle from the sun gear. it should work like a circle turning tool
but with more precision. the teeth count i ve thinking trying first are. ring 52 planets 16 sun 20.My problem is
i havent had a way to cheaply make the gears. any ideas ?

i have some drawing of it ill post later

[YouLuckyFox]

i have some drawing of it ill post later

Please do, I am interested in this idea of yours.

[critmass235]

i just redraw it couldn't find the old one. the brown part is the extruded part to the sun gear. that way the input from the sun gear is the same size of the ring gear you hold still. this video will help understand planet gears if your unfamiliar[youtube] http://www.youtube.com/watch?v=ECljAo1q1RQ[/youtube] i was think of using this site for the templethttp://woodgears.ca/gear_cutting/template.html
the reduction im aiming for on my first is 3 but the teeth count i stated earlier will make is close enough . the whole point of this is to make a tool thats helpful for harder security pin lock.

[l0ckcr4ck3r]

Really nice idea critmass235!!!
the gearing effect will allow you more precisely control the tension force and feedback will be amplified
The best starting point i can think of is taking apart and old cordless screwdriver for the ring gear. You will probably find its a standard pitch and then just buy the planets and sun gear to fit.
Making your own gears is kinda involved and custom gears are expensive.
I have used a piece of software in the past for some projects called "Gear Template Generator". This helps figure out the tooth count and geometry.

https://www.youtube.com/watch?v=9MycFQKnZkA

Good luck and let us know how it works out!

[YouLuckyFox]

It would be neat to have something like this with a clutch built in so that it would be like an adjustable torque wrench: put too much turning force and it would turn freely, it would certainly help a beginning lock enthusiast to not over-torque a plug. Thanks for the PM critmass235, I think I have a hang for this idea now. Please keep us posted on any new developments.

[critmass235]

that's the templet site i was referring to. i was thinking since its not a high rpm ( less then 1) max out the contact angle to 45 so when backing out of false set it would have less play in it. the specs on that free gear templet i was wanting to try first are 45 degree contact, 4 or 5 mm teeth spacing the ring is -52 teeth the planets 16 the sun 20. i have look into gears for other things but i haven't found one i could afford and that have the right size ( i was hoping some type of modeling ones). i trying to find a machine shop that can do it but nothing where i live can do small and accurate cuts. ive seen some places online that say they do cnc laser/plasma/waterjet cutting but i have no clue how to use them because most want it in autocad. i thinking i might be able with a band saw or scroll but i dont own one. i like the idea of i toque wrench effect. im trying to turn a automatic transmission into a lock pick so it would be funny another idea came from cars.

[YouLuckyFox]

I used to work for and plan to return to a real nice machine shop in Washington, they can do stuff like you're talking about. What you're looking for is a place that has hobbing machines. The place I worked at had CNC for the more major operations (turning and milling) but had manual machines for hobbing, splining, and broaching. With regard to AutoCAD you definitely want to have an engineer or someone familiar with SolidWorks, Inventor, AutoCAD, etc. to make an official engineering drawing for you. I don't know what kind of factors are needed to be considered to know how many teeth are needed on your gears, let me know if you do; I guess an engineer would be a good person to consult on this, too.

[l0ckcr4ck3r]

Id be happy to do the solid works stuff and can generate CAD drawings from that. YouLuckyFox is absolutely right about hobbing though… fly cutting produces second rate gears. When you say Contact angle… I'm guessing you mean Pressure Angle? these are standard at 14.5, 20 and less common at 25 degrees. it is possible to make some trial gears with basic machine tools, just to test the idea out. You can use a section of old bandsaw blade to make the dividing head and then use a mill or lathe to fly cut the gears. Ring Gears can't be made this way though.

[smokingman]

You could just get an old style radio tuner with planetary gears already in it
to try the system out and tweak the ratios after deciding if it is useable or not.
I get them from radio parts suppliers for building tunable AM radio antennas ( Loop and Loopstick)
they have smooth and slow movement for precision tuning, and may be what you are
looking for as a cheap test unit.
I think the problem might be the size,though some are not much bigger than a regular tuner,
and how to mount it .
Just a thought.

[smokingman]

Just to clarify, the whole thing is built into a disc behind the knob and is one unit, so the size is hardly bigger than the knob its'self and has brass gears.
But still, mounting it on something you could hold and operate with one hand might be tricky but doable.

[critmass235]

the pic i post was a quick redrawing since i couldnt find my old one.the planet gears would be sandwiched between overlapping plate on the sun and ring to hold it together so it would be one piece. my idea to cut the ring with a band saw was to cut through the ring because its use is less the 1 rpm and the housing would cover it. i know homemade would only be a proof of concept and higher precision is really needed. contact angle is
what the templet generator uses as one of the specs. i choose 45 because it would be easier to cut. i got some old aluminum sign to work with at the moment. my current tools are needle files and a dremel. i would like to look into plastic gears but i think would wear out quicker and the sun gear has to be bigger then the lock cylinders it used on.. for the radio gears where do you get them?( radio shack ?) after i get a chance to make i was thinking to either add a weight to the ring gear or something like the wrist strap on a sling shoot. but you just hold it still with your middle finger too.

[dll932]

This sounds like a good candidate for 3D printing. On a site like www.thingiverse.com or www.shapeways.com there may already be a planetary gear set available.

[critmass235]

3d printing i think will be the cheapest way to make a first prototype .some premade ones seem really cheap (20ish$). i ve been wanting to learn how to use blender andway. that way i can make the whole thing in 3d. i have no clue how to use blender but a lot of tutorials. so it might take me a lil while.

[critmass235]

i got bored last night and using trash around the house made a some what working prototype. the gears are pill bottle caps. the ring gears is a metal cd case lid. its got alot of friction in it that messes up the feedback but it does give more precision (i think the feedback will be fix if the gears move free .... mine doesn't ) ill post some pic when i find my camera. (hopefully later to day)

[critmass235]

heres some pics