[burpg] Re: Measuring Servo Spline
- From: Mehmet Akbulut <meak@xxxxxx>
- To: burpg@xxxxxxxxxxxxx
- Date: Mon, 18 Aug 2014 01:18:53 +0300
Alessandro is right. To get the least amount of skew/distortion,
perspective crop will help.
Unfortunately there is no data sheet. I'm not in Boston, otherwise I would
have done it.
On Mon, Aug 18, 2014 at 12:46 AM, Alessandro Cesar Dias Gomes Filho <
acgfilho@xxxxxx> wrote:
> Do they not have a datasheet?
>
> Also, whoever does this might want to do a perspective crop on the picture
> in Photoshop to make sure it is isometric.
>
>
> On Sun, Aug 17, 2014 at 2:24 AM, Armor Harris <armorharris@xxxxxxxxx>
> wrote:
>
>> Hey guys,
>>
>> We need someone back at the lab to measure the old e-regulator servo
>> spline. Looks something like this
>>
>> http://www.servocity.com/html/hitec_servo_splines.html#.U_A6QvldV8E
>>
>>
>> I think the best procedure here is to use a high resolution camera (read:
>> not an iphone) to take a perfectly 2D picture of the servo spline with a
>> pair of micrometers set to a known distance on the same plane as the servo
>> spline (calipers probably aren't accurate enough unless they're really nice
>> ones).
>>
>> Then, someone can use imageJ to measure the length in pixels of each
>> spline tooth and use the distance between the micrometers in the same plane
>> as a pixel to length ratio. ImageJ makes it really easy.
>>
>> I've done this before on another application, I used an SLR with a stock
>> lens and a tripod and it worked pretty well. The setup was in a difficult
>> environment but I was still able to get accuracy of less than .001" You can
>> probably do better since it's in a well lit lab environment and you can
>> control the photo a lot better. I would suggest is setting up the camera
>> for maximum contrast so that when you zoom in, you can still see sharp
>> lines.
>>
>> Once we get that measured, we want to try using wire EDM to machine our
>> own attachments for high precision valves like the thrust vector control
>> and the throttle valve. This could potentially make our servo driven valves
>> a lot more reliable and rugged, so it's a really big deal if we're able to
>> do this.
>>
>> Anyone up for it?
>>
>> Armor
>>
>
>
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