Tight Arse Stir Plate

[Tony]

YEah that was me

I even broke all the fan blades off.

IT has to run at the lowest speed as the stir bar flips out.

After reading this i may get a shorter one. mine is about 50mm long

cheers

 

[jimmy01]

Hope someone can help

I am building a stirplate using the circuit recommended by LethalCorpse. Jaycar were out of 3 pin LM317. They only had 2 pin units with the body of the unit being the output terminal. However I cant work out which pin is th input and which is the adjust. The brand is STMicroelectronics. Looked on their website but the drawing is not real clear.


Anyone know?

Cheers
Jimmy

 

[LethalCorpse]

Odd, they should always have heaps of those in stock. Is it the small, surface mount type, or the hulking great round job? Either way, here is the datasheet with the pinouts. Note that the pinout diagrams are a top-view, which means it's flipped if you're looking at the bottom.

 

[jimmy01]

Odd, they should always have heaps of those in stock. Is it the small, surface mount type, or the hulking great round job? Either way, here is the datasheet with the pinouts. Note that the pinout diagrams are a top-view, which means it's flipped if you're looking at the bottom.

Hi LC

Its the great hulking round job. I saw that diagram but was not sure which way the top on this regulator. If you hold the regulator the same way as it is in the diagram then the writing on the device is running from the bottom of the device to the top not left to right.

Thanks
Jimmy

 

[LethalCorpse]

The side that the pins come out of is the bottom, the side with the writing is the top

 

[jimmy01]

The side that the pins come out of is the bottom, the side with the writing is the top

Yes I understand that. What I am unsure of is which pin is the input. When looking at the underside of the reg there is no discernible top or bottom pin. It depends which way you hold it and there is no reference point on the device

I might have to go to DSE and get a 3pin LM317

 

[LethalCorpse]

Have another look at the underside. Note the the two pins are closer to one end than the other. If you hold it so that you're looking at the bottom of the reg, with the two pins towards the right, the top pin is adjust, the bottom pin is input.

 

[jimmy01]

Have another look at the underside. Note the the two pins are closer to one end than the other. If you hold it so that you're looking at the bottom of the reg, with the two pins towards the right, the top pin is adjust, the bottom pin is input.

Thanks LC

Will give it a try

Cheers
Jimmy

 

[atkinsonr]

Yes I understand that. What I am unsure of is which pin is the input. When looking at the underside of the reg there is no discernible top or bottom pin. It depends which way you hold it and there is no reference point on the device

I might have to go to DSE and get a 3pin LM317

If you're looking for pin outs on any component, you can google the product name and look for a datasheet, they're usually in PDF format and from the manufacturer.

eg: http://www.national.com/ds/LM/LM117.pdf

I'm not sure exactly which one you have, but if you look on page 2 of the above link, there are a few pin outs. Otherwise - google the exact product code written on the side of the component.

Hope this helps

Richy

 

[litre_o_cola]

After having a quick read of the first couple of pages I threw one together from the spare puter parts in the shed.
All works well although I don't have a proper stir bar yet but as I found out the young fella's magnetix have rare earth magnets in them and does the job quite well for the time being.

 

[Uncle Fester]

After having a quick read of the first couple of pages I threw one together from the spare puter parts in the shed.
All works well although I don't have a proper stir bar yet but as I found out the young fella's magnetix have rare earth magnets in them and does the job quite well for the time being.

I used an old 12v PC case fan and glued 2 rare earth magnets from jaycar onto it.

I use a variable power supply from Tricky Dicky. I find 9v gives a really nice vortex.


Cost nuffin. To buy new, about $20.

Festa.

{Edit} I use a commercial stir bar - cost me $12 {/Edit}

 

[Damian44]

What would be a good size stir bar for a 5 liter flask? Could you pick one from link, as i have an account with them? TYVM

http://www.livingstone.com.au/search_resul...search=stir+bar

Ive got a multi voltage adaptor and a PC fan, so im off to Jaycar for a jiffy box, some magnets and something to connect my fan to the power adapter.

 

[Wolfy]

What would be a good size stir bar for a 5 liter flask? Could you pick one from link, as i have an account with them? TYVM

I believe that the size of the stirbar is more related to the spacing of your magnets than anything else - you want a stirbar that is slightly smaller than the spacing of your magnets for it to work best.

 

[haysie]

updated diagram to make it a bit neater and include the new values.
Jaycar parts:
LM317T - ZV1615
5k linear pot - RP3508 or RP7508
knob to suit - pick one. Not the ones which say "spline" or suit 9mm pot
680ohm resistor - RR0568
switch - pick one. Any will do, so long as it's a latching type, not momentary. Pushbuttons, toggle switches, rockers, etc.
10u cap - RE6070
100n cap - RC5360

Heading too Jaycar over the weekend for the parts, any suggestions re what size magnets I should purchase whilst there? 120mm fan, 2ltr flask

 

[litre_o_cola]

The magnets at Jaycar I bought were in a belt arrangement (for hanging light tools up) about 12mm x 3mm you get about 8 of them for $14

 

[haysie]

Thx litre o cola,
they only had 2 sizes small 8-10mm then about 15mm, $10.95 for 4 small

I am having trouble with magnet placement, they come flying off, using double sided tape, wrapping them in electrical tape around the blade, nothing is making them stick, i didnt want to use super glue cos i figure i might need to move them, and another question does it matter which way fan is facing up or down?
Thx



i am placing 1 of each nth and sth

 

[smudge]

haysie,

If you are using the rare earth magnets and not the long bar magnets, secure them to the hub not the blades. Mine are only
sticky taped on and haven't moved.

Cheers,
smudge

 

[Wolfy]

I am having trouble with magnet placement, they come flying off, using double sided tape, wrapping them in electrical tape around the blade, nothing is making them stick, i didnt want to use super glue cos i figure i might need to move them, and another question does it matter which way fan is facing up or down?

You should be able to stick them to the outer edge of the hub without too many problems.
Then you can face your fan up or down depending on how you can best stick your magnets to the hub, in general you'll only be able to stick your magnets on one side.

PS: Had you said you were going to make one today, I could have given you one of the HDD's I have here to pull apart for the magnets, there are 2 in each drive.

 

[Franko]

Get yourself a decent sized washer and glue it to the fan and then place your magnets to the washer-works a treat

Franko

 

[litre_o_cola]

Get yourself a decent sized washer and glue it to the fan and then place your magnets to the washer-works a treat

Franko

+1 exactly like franko has said, I glued a decent sized ( bout 1 1/4" ) washer to the hub and then placed the magnets on 1 N and 1 S, then mount it hub side to the board using small washers as packers giving about 2mm clearance. Using one of the young fellas magnetics I can get a whirlpool going that is about 4" deep and only gets unstable at max revs.