# Very Confused Need Help!



## speedre9 (Dec 11, 2013)

O.K. I'm confused. If I want to power my upcoming spindle build with a d.c. motor; 
What should I be looking for?? How do I Choose one for spindle power??
What about r.c. motors normally used for r.c. model helicopters, are they good enough?? How do I know which to chose??
What do I need to power it??
I need to be around 22k r.p.m.
I am finding this to be very confusing and hard to find the right stuff. HELP, please comments


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## Chucketn (Dec 11, 2013)

Not that I could answer your question, but more info is needed.
What is the application for the spindle? What materials will you work with? Wood, metal?

Chuck


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## speedre9 (Dec 11, 2013)

O.K. I'm confused. If I want to power my upcoming spindle build with a d.c. motor; 
What should I be looking for?? How do I Choose one for spindle power??
What about r.c. motors normally used for r.c. model helicopters, are they good enough?? How do I know which to chose??
What do I need to power it??
I need to be around 22k r.p.m.
I am finding this to be very confusing and hard to find the right stuff. HELP, please comments 		
Must add this information.
I will be cutting only styrene sheet stock, 0.0625" through 0.090".
 Primary cutter will be a two flute end mill of either 0.0625" or 0.125" dia. most likely on a 0.125" dia. shank.
Also. when picking pulleys, if the driven is 2.00" dia. and the driver is 1.00" dia is the motor r.p.m. doulbled
I may need to double the r.p.m.:nuts:


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## PurpLev (Dec 11, 2013)

why not incorporate a trim router for that build? that would give you the motor at RPM you are looking for and a collet for the type of cutters you are planning on using.


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## Rbeckett (Dec 11, 2013)

In order to step up the RPM the driven pulley needs to be 1/2 the size of the driving pulley to double the speed of the shaft with the tool.  You could also triple or quadruple the speed of the quill by following the same logic.  But remember that for every doubling of speed you cut available torque by a factor of 4.  On thin styrene like you describe it is probably not too important to have a lot of torque, but if you ever decide to use a thicker or tougher material than the styrene you will probably have plenty of RPM's available but lack the Horsepower to perform your task at the same speed.  Again cutting the torque will slow down how quickly you can move the material or the quill.  So I would recommend overbuilding the machine to use the  largest motor you can find that runs at 3600 or faster RPM's and use multiple pulleys to achieve the high RPM's you are looking for at the quill.  A 2:1 ratio into another 2:1 @ 3600 RPM input would yield 14.400 RPM at the bit.  In order to increase it to around 22K you would need another set of 2:1 gearing to achieve your target speeds.  It will be extremely important to address stiction and friction to get rid of as much of the parasitic load on your system as possible.  You could reduce the number of pulleys by using a 4:1 ratio in the initial step and a 2:1 in the final step and eliminate one set of pulleys and the alignment and spacing issues that arise when building such a machine.  If you used this approach I would opt for a Totally enclosed fan cooled (TEFC) motor to prevent chips and trash from getting inside the motor and causing durability issues in the future.  Hope these thoughts help  with your design.  If you would like to discuss it further please let me know here or in a PM and I will be thrilled to help you design it as much as possible.  I think what you want to do is withing the realm of feasible you just need to address certain issues before you begin to build and spend you hard earned money.

Bob


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## FanMan (Dec 11, 2013)

Why does it need to be a DC motor?  For an application like this a Dremel tool might be a better choice; they're variable speed and already have collets.

22K will likely melt styrene rather than cutting it, though.


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## xalky (Dec 11, 2013)

And to add to the others comments about a dremel/router/electric die grinder, you can add one of these to regulate the speed if it doesn't already have variable speed. http://www.harborfreight.com/router-speed-control-43060.html


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## speedre9 (Dec 12, 2013)

why not incorporate a trim router
That is exactly what I do not want. I have a, 1 h.p. v.s. Router body that I have used in the past, just too darn loud. It is not for a work shop in a spare room next to my bedroom. I am becoming increasingly aware that for my usage the Dremel, which I also have on hand, will be the spindle of choice. There are times, when the answer is right there in front of you but, you choose not to see it. Thanks to all for their insight and comments.


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## xalky (Dec 12, 2013)

speedre9 said:


> why not incorporate a trim router
> That is exactly what I do not want. I have a, 1 h.p. v.s. Router body that I have used in the past, just too darn loud. It is not for a work shop in a spare room next to my bedroom. I am becoming increasingly aware that for my usage the Dremel, which I also have on hand, will be the spindle of choice. There are times, when the answer is right there in front of you but, you choose not to see it. Thanks to all for their insight and comments.


Some of these high speed rotary tools are noisy, you're right. But there are some out there that are more quiet than others and by reducing the speed, you can quiet them down further. A good quality rotary tool would be worth the extra money spent. You'd still be saving a whole lot vs. building your own, and it's a lot simpler too.


Marcel


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## speedre9 (Dec 13, 2013)

You may well be correct. It is after all a matter of money, too much and it's overkill, too little and it's not strong enough. More thought and exploration is needed I think


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