Re: [CAD_CAM_EDM_DRO] Re: Encoder circuits for parallel port hookup?

The mechanical that I have tried I have not been very pleased with. It get
worse the longer you use it. Gray Hill makes an optical that is not very
expensive Check out Digikey.
Jim

----- Original Message -----
From: "AbbyKatt" <cnc@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Thursday, February 24, 2005 5:18 PM
Subject: RE: [CAD_CAM_EDM_DRO] Re: Encoder circuits for parallel port
hookup?


>
> Thanks for the response Art!
>
> Hmmm.. I ended up getting some pretty cheap mechanical encoders, and
> just used some gearing to increase the res... But I seem to be getting a
> problem with this. I'm guessing there may be some bouncing of the
> signal? I'm using Mach2 (will use Mach3, so I can do both X/Y soon)..
> Sometimes it seems like the program will detect 2-hops instead of one,
> and sometimes it'll switch out of the MPG mode (I'm guessing this is
> debounce and that Mach2 is detecting an invalid Quadrature sequence and
> wisely bailing out of the mode?)
>
> Can I use some little capacitors with resistors across them or such to
> filter this?
>
> Thanks
> Abby
>
>
>
>> -----Original Message-----
>> From: art [mailto:fenerty@...]
>> Sent: 23 February 2005 13:44
>> To: CAD_CAM_EDM_DRO@yahoogroups.com
>> Subject: Re: [CAD_CAM_EDM_DRO] Re: Encoder circuits for
>> parallel port hookup?
>>
>>
>>
>> Hi:
>> >>>> What I am looking for is the circuit diagrams that show
>> how to hook
>> > up
>> >> an optical encoder to the parallel port (I a
>>
>> No signal filters are usually necessary, you hook the A and
>> B quadrature
>> up to the pins on
>> the printer port directly, and you have to hook the signal
>> gound to pin 25.
>> Thats it. Mach3 can read
>> up to 7 of these if you have enough pins, but when reading
>> from a printer
>> port, your limited to the nyquist
>> frequency of the program reading it in terms of speed. In
>> Mach3's case, at
>> 25Khz mode, you are limited to
>> about 12500 pulses per second on the encoder, howver, Windows
>> being Windows,
>> I recommend a 10000
>> pulse limit and 20000 in 45Khz mode.
>>
>> I have seen some DOS software that wil read faster
>> though, and it is
>> possible for a Windows DRO program to
>> do up to 50000 per seconjd from an encoder if it doesn't have
>> to do motor
>> movements and such to limit
>> the interrupt time. I have letters from several that have
>> encoders hooked
>> up as semi-closed loop correctors
>> and they seem to work well within those limits. Personally, I
>> haven't had
>> time to hook up my linear scales to Windows yet,
>> but intend to do so next month to put closed loop corrections
>> into the code
>> base for Mach3 anyway..
>>
>> Marris has a post recently on the gecko group about hooking
>> an encoder
>> directly to a motor to make it follow the encoder
>> with very simple circuitry as well...
>>
>> Thanks,
>> Art
>> www.artofcnc.ca
>> ----- Original Message -----
>>
>>
>>
>>
>> Addresses:
>> FAQ: http://www.ktmarketing.com/faq.html
>> FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
>> Post Messages: CAD_CAM_EDM_DRO@yahoogroups.com
>>
>> Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
>> Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
>> List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com,
>> wanliker@..., timg@...
>> Moderator: pentam@... indigo_red@...
>> davemucha@... [Moderators]
>> URL to this group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
>>
>> OFF Topic POSTS: General Machining
>> If you wish to post on unlimited OT subjects goto:
>> aol://5863:126/rec.crafts.metalworking or go thru Google.com
>> to reach it if you have trouble.
>> http://www.metalworking.com/news_servers.html
>>
> http://groups.yahoo.com/group/jobshophomeshop I consider this to be a
> sister site to the CCED group, as many of the same members are there,
> for OT subjects, that are not allowed on the CCED list.
>
> NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM.
> DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........ bill
> List Mom List Owner
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>
>
>
>
> Addresses:
> FAQ: http://www.ktmarketing.com/faq.html
> FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
> Post Messages: CAD_CAM_EDM_DRO@yahoogroups.com
>
> Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
> Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
> List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@...,
> timg@...
> Moderator: pentam@... indigo_red@... davemucha@...
> [Moderators]
> URL to this group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
>
> OFF Topic POSTS: General Machining
> If you wish to post on unlimited OT subjects goto:
> aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it
> if you have trouble.
> http://www.metalworking.com/news_servers.html
>
> http://groups.yahoo.com/group/jobshophomeshop I consider this to be a
> sister site to the CCED group, as many of the same members are there, for
> OT subjects, that are not allowed on the CCED list.
>
> NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM.
> DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
> bill
> List Mom
> List Owner
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>