[burpg] Re: Measuring Servo Spline
- From: Cory Absi <cory.absi@xxxxxxxxx>
- To: "burpg@xxxxxxxxxxxxx" <burpg@xxxxxxxxxxxxx>
- Date: Mon, 18 Aug 2014 11:01:23 -0400
I will be in Canada until Sunday and the entire week after that I am devoting
to the MkIIb and rocket team stuff so if nobody does it by next Monday I will
do it. I have my brothers DSLR and a tripod and photoshop so I should be good
to go lol.
-Cory
Sent from my iPhone
> On Aug 17, 2014, at 6:36 PM, Armor Harris <armorharris@xxxxxxxxx> wrote:
>
> Yeah you only have to get one tooth of the spline, the diameters, and then
> revolve it. So just get super close up on one tooth
>
>> On Sunday, August 17, 2014, Mehmet Akbulut <meak@xxxxxx> wrote:
>> 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
>
>
> --
> Sent from my phone
Other related posts:
