MadModder
The Shop => Electronics & IC Programing => Topic started by: PekkaNF on May 19, 2017, 06:15:26 PM
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So, when M6 is not standard M6.
Bought M6 thermocouple with PID controller. I made a fitting with standard M6x1 thread but the thermocouple would not fit in it.
OD is 6,22 mm and lead is 1,25 mm as close as thread gauge shows it. M6 bolt next to it on the picture.
Suggestions?
Pekka
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Pekka,
Looks like 1/4" X 20 TPI (1.27mm pitch) Whitworth thread to me.
Phil.
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I had exactly this problem the other day installing the T/Cs on our new reflow oven. They are indeed 1/4"... Which is odd....
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Could well be 1/4" X UNC if it's Chinese, which is very close to Whit but 60 degree rather than 55
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I cant recall If I got UNC or BSW.. I just walked into the "Old peoples fasteners" section of the hardware store and grabbed a packet with 1/4" written on it.... :thumbup:
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It deos look like UNC, walked into shop reachec for 1/4 UNC marked drawer, pulled out packet of two taps, checked that they were 1/4" and came home. At home I noticed that the taps are 1/4" UNF! dikeytyduckeytyfiqeyty. I "always" double check, it must be my specksavers moment or it's about time to have my head checked.
This really does not want to go together voluntarily.
Pekka
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Walked back to shop and that spot was filled UNC/UNF taps - all mixed!
The "M6" was 1/4-20 indeed!
It needs some brackets to holde the puck against the vat.
Pekka
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Pressed three nuts, put three springs and screws to it.
This holder lies on small ledge of the fritti cooker frame, when the dish is put top on on it springs will press the puck that contains thermoelement onto enameled dish.
It works, but is a bit slow....Temperature overshoots and takes 10 minutes to stablilize to 80 degrees C.
Pekka
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PID parameters can be painful to set up correctly.
I quess there are as many methods to do this as there are dudes to set them up.
In fact, there is so much information on this subject int he WWW that it is just overwhelming.
I quess You already did what there is to be done for those parameters.
If not, then there might be something to do here.
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Controller parameters are lot of fun. When I was young, used to tune electrohydraulic servosystems. There was allways a starting point, but few cascaded loops took some thinkking and time.
I used a lighter sensor immersed into liquid, improved time constat a whole lot.
Pekka