Quote:
Originally Posted by kinetic
Hi,
This improvement gives me approximately 8500 counts per 360 degrees on DEC axis and
a whopping 25,000 counts per 360 degrees on the RA!
That's 0.042° or about 2.5minutes DEC (was previously about 12 minutes)
and 0.0144° in RA or about 0.85 minutes.
Steve
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Steve,
could you please also explain how you got the figures above, just trying to understand it as I'm working on a bartels system as well and am stuck at the encoders.
you mentioned 8500 ppr on the DEC using a 144 slot wheel.
to get 8500 ppr using quadrature, would'nt you need 8500/4 = 2125 slits on the encoder wheel?
for the RA, you mentioned 25000 ppr. but you're using the slotted wheel from the mouse which I'm guessing is 160 slits? (320 dpi)?
so if the gearbox is reducing and you really slow down the encoder wheel rotation, unless the slits are extremely fine, there won't be pulses when the light beam is between the slits and the encoder is slowly turning till the slit edge is reached?
for 25000 ppr, would'nt you need 25000/4 = 6250 slits on the encoder wheel?
this is the part that confuses me. how do you cram so many lines even if using laser printers? only other option would be to reduce it photographically.
I found a nifty program that is specifically for optical encoder patterns if you're interested.
http://www.iceinspace.com.au/forum/s...ad.php?t=62537
I'm going to try printing a wheel using the professional printing outlets provided they have high resolution lasers printers.