Chester 626 mill CNC Conversion

[Rob.Wilson]

Cheers John S ,,,,,,, i will call in tomorrow 


  i new that would make you laugh Dave ,,,,,, will let you no ,,,, see how i get on at RS .


Hi John ,,,,, made a note of that part number  too  

I would like to have ago at making it at the (tomorrow night) weekend ,,, have board , found plugs,,and chip mounts ,,,,,,JUST NEED CHIPS 



Rob



 

[John Swift]

Hi Rob,

now I've had a look at the data for the 74245 and 74541 , the new revised the layout can be  use with either IC
assuming the D type connectors are connected via a ribbon cable

note when  pin 1 is connected to 0V the input and output pins are on opposite sides ! (74541 o/p  pins 11 to 18 , 74245 o/p pins 2 to 9 )

pin 1 on the 74245 controls the direction of data flow
and at +5v the data in and out will match that of the 74541

as before the 56 ohm resistors are optional


just a thought ,the break out board you have could be used
if you make a cable / adaptor ,connecting the manual control  to the breakout boards 25Way connector

and wire a 25way D-type  to the 5 pairs of step and direction terminals to connect to the printer port

  John

PS - without a copy of the manual I am not sure if an enable input needs connecting to GND , assuming open circuit  = logic 1  ?

[Rob.Wilson]

Wow John ,,,,, you have been busy 


I have already started on BOB 1.0     just needs soldering .   

just a thought ,the break out board you have could be used
if you make a cable / adaptor ,connecting the manual control  to the breakout boards 25Way connector

and wire a 25way D-type  to the 5 pairs of step and direction terminals to connect to the printer port

I would rather keep that as a spare ,,,,,, more fun building your design 

PS - without a copy of the manual I am not sure if an enable input needs connecting to GND , assuming open circuit  = logic 1  ?

Its only one page ,,, mostly chinglish    ,,,,,,,I had it connected to ground  , What i can tell you is when the enable button is pressed the selected pin in Mach goes High and stays High  , only goes Low when another pin is selected and enable is pressed ,, any help ?

i will scan handheld sheet 


Thanks Rob   

[Rob.Wilson]

Hi Lads

Not allot done today ,,, soldered the parts to the board as per Johns diagram     ,, although i did move the E stop to the other side of the board so i can just link it straight across to the first BOB E stop input  .





Hopefully i should get time to pick up the chips tomorrow    ,,,,, i also  still have the leads to solder to the board .

Rob

[John Swift]

Hi Rob

thats  looking great 

for now you can check you have +5v on pin 20
and 0v  on pins 1,10 & 19

as soon as you receive the IC's you can test the board
with the notched end of the ICs nearest  to the other breakout board
you will find all the remaining pins at +5v until the control switches or MPG
connects a pin to 0v (GND)


    John

[Rob.Wilson]

Cheers John 

for now you can check you have +5v on pin 20
and 0v  on pins 1,10 & 19

Got Those voltages at those pins 

as soon as you receive the IC's you can test the board
with the notched end of the ICs nearest  to the other breakout board
you will find all the remaining pins at +5v until the control switches or MPG
connects a pin to 0v (GND)

Installed chips ,,,,,, dont have +5v on the other pins     ,,,,,,,, all pins on the left side of chips at 0v ,,,,,, nothing on the Right side



Rob

[John Swift]

Hi Rob

just had a look at your pictures and it looks OK  ,should of worked

double check the ICs are in the right way up --- see  the diagram

with nothing on either the input or output pins
its as if the level on the output enable pin 19 is wrong
and the i/o pins are high impedance ,but it says in the data its active low

easy way to prove the enable input is correct , unplug the IC and put it back in with pin 19 bent out to miss the socket ,
if the ic now works the connection is wrong

  an unconnected TTL IC input should count as a logic one

I'll have a look to see if I have an IC  to prove the circuit


  John

[Rob.Wilson]

Hi John

Did that ,,,,,, and with pin 19 out ,,,, there is nothing on both sides of the pins  .


Rob 

[John Swift]

  Hi Rob ,


I've found an IC  on  an old board and de-soldered the   DM74LS245N  

 connecting pins 1 , 10 and 19 together to 0v
and pin 20 to +5v with a few wires dead bug style  

this is what I measured from pin 10   (0v / GND)

pin 20 = 5.08v  (positive supply pin)

input pins 11 to 18 = 2.5v  ( pin not connected to any thing)

output pins 2 to 9 = 4.85v

connecting an input to 0v , the corresponding  output =0.1v

so it works as expected

whats   RS part number of your IC's  ?


   John
 

[Rob.Wilson]

hi John


RS p#  156-9803


good too here you got yours working 


Rob

[John Stevenson]

You have soldered the chips in and not MiG welded them haven't you ? 

John S.

[DMIOM]

Hi John

Did that ,,,,,, and with pin 19 out ,,,, there is nothing on both sides of the pins  .


Rob 

Rob,

Maybe I can hazard an O/T guess why you can't find any voltage - in this picture you showed us the electrickery to consume the power, and the igniter - but there's no sign of the steam plant or dynamo to generate the power?

Dave

[Rob.Wilson]

    John S ,,,,,,, thats were i went wrong 

Dam its needs   electrickery     Dave ,,,,,,,, bit short on that up north 


Well looks like it my fault ,,,,,,,, nowt wrong with the chips wired them up on a bread board ,,,,,, and they work    just as John said it would 


Rob

[John Swift]

Hi Rob ,

I am sure your board is correctly wired

the only thing I can think of is the HCT version being  a CMOS device , needs the input pins connecting to +5v via a resistor

unlike earlier devices like the 74LS245 version I've tested

you can prove this by connecting one  inputs of a 74hct245 to +5v   (with  pin 19 back into the socket !)

if you now have +5v at the output ,

then you need to use  pull up resistors connecting the input pins to the +5V
(or another version of the IC like the 74LS245)

if you re-used the 56 ohm resistors for the switch inputs the switch will pass 0.1A to GND

without any info on the manual pulse generator
try 4k7 resistors to connect the A & B inputs to +5V

the connect the un used 74hct245 inputs to either 0V or  +5V

another way is to use single in line resistors

   John

[Rob.Wilson]

Hi Chaps 

I made a start on making new table ends yesterday as the original ones could not be modded     

They should look like this ,,,,, i hope



Now if i had of finished my cupola furnace i would have cast them    but as its still under a tarp in the yard un-finished it will be of welded construction 

a few bits of bright mild steel with the weld prep done


the parts tacked together  ready to be welded


welded 


Then into the furnace at blast mark 5 for half an hour 



There they will stay to cool slowly ,ready for tomorrow night 

Rob 

[DaveH]

Rob,

Nice bit of welding

And blast mark 5 looks hot!!!
 
DaveH

[doubleboost]

That is better than elecrronics
Welds look a bit dry 
Spot on mate
John

[John Swift]

Hi Rob,

they look great

wouldn't be any better if you had cast them

can't wait to see how you machine them

     John

[HS93]

Very nice Looking welding, but can I ask why did you space it is it to get the weld to penetrate more, Not from a metal background , whatever it still looks nice and neat ( compaid to the attempt I made once)

Peter

[John Stevenson]

Peter,
It's a cunning Geordie trick to save metal   

John S.

[saw]

Still working on it, I thought you was finish by now 

[John Stevenson]

Hi Chaps 






Rob

Rob,
How do you get a surface finish like this in the bores ? 

John S.

[John Rudd]

Hi Chaps 






Rob

Rob,
How do you get a surface finish like this in the bores ? 

John S.

Aahh....that'll be another cunning Geordie trick....

Nice work Rob, keep the pictures coming..

[HS93]

Hi Chaps 






Rob

Rob,
How do you get a surface finish like this in the bores ? 

John S.

Aahh....that'll be another cunning Geordie trick....

Nice work Rob, keep the pictures coming..

I wonder why you can never see Robs reflection in a mirrored surface,  WOO Scary 

                                                      Peter

[arnoldb]

Good going Rob  - very nice welding as always.

Nice to see the furnace fired up; must be getting colder there 

 , Arnold