Homebrew PCBs

Hello Andy,

Unfortunately, peristaltic pumps are not suitable for obtaining the necessary flow and pressure for spray ecthing. I had reviewed some of the earlier 80's spray etcher models, and nobody was using a peristaltic pump.

Regards.


--- In Homebrew_PCBs@yahoogroups.com, "Andrew Volk" <amvweb@...> wrote:
>
> Has anyone looked at peristaltic pumps?  The only thing that comes in
> contact to the etchant is the rubber hose that goes through the pump.  I got
> one off of eBay, as well.  The only issue with this kind of pump or the less
> expensive pumps in this thread is the volume they can push.
> 
>  
> 
> Andy
> 
>  
> 
> From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
> On Behalf Of Robin Whittle
> Sent: Tuesday, August 21, 2012 9:03 PM
> To: Homebrew_PCBs@yahoogroups.com
> Cc: Ben L
> Subject: [Homebrew_PCBs] Magnetic drive pumps for spray etchers
> 
>  
> 
>   
> 
> From the thread: "Kepro bench top spray etcher":
> 
> An eBay search for:
> 
> magnetic pump
> 
> produces hundreds of results, some of them for small pumps costing less
> than $100. Sorting by "price with shipping" groups similar products
> together.
> 
> Perhaps not every one of them has a magnetically coupled impeller -
> thereby presumably having no metal shaft or seals which could be
> attacked the the etchant. Maybe some of these are truly magnetically
> coupled, with an impeller magnet totally sealed in plastic, and with
> enough pressure to drive spray nozzles.
> 
> I think the challenge is to find one or more to make a compact
> double-sided spray arrangement, with a smallish amount of etchant.
> Prices are USD$ with shipping to Australia.
> 
> . http://www.ebay.com/itm/221017721016 $27
> . Anti corrosion. 5 litres per minute.
> 
> . http://www.ebay.com/itm/221109440478 $20
> . Probably too small.
> 
> . http://www.ebay.com/itm/270961751604 $25
> . Probably too small, but has photos of the magnetic drive system.
> 
> . http://www.ebay.com/itm/130481962264 $21
> . Another small cheapie - photo shows magnetic drive system.
> 
> . http://www.ebay.com/itm/180947111931 $30 + $53 shipping
> . Iwaki 100V AC induction motor, uses a capacitor to phase lag the
> . second winding. Is the capacitor internal or external?. From a
> . photographic processing machine. 6 available.
> . At 50Hz, 11 litres/min. Max head 1.5 metres.
> 
> . http://www.ebay.com/itm/180955597871 $70 + $80 shipping
> . Larger Iwaki pump, one only. 27 litres/min 3.1 metre max head.
> . This would be be highly suitable.
> 
> . http://www.ebay.com/itm/180954727143 $90 + $135
> . Larger Iwaki pump.
> 
> . http://www.ebay.com/itm/130681739875 $50 + $51
> . Iwaki-Walchem New Old Stock. 220VAC high capacity.
> 
> . http://www.ebay.com/itm/130743582615 $83
> . High capacity 24 volt with speed control. This is a brushless
> . motor, meaning it has electronics to drive three (I guess)
> . windings, with a permanent magnet rotor which follows the resultant
> . rotating magnetic field. The rotor's shaft is ceramic. So I think
> . there is no motor -> magentic coupler, just that the permanent magnet
> . rotor and its shaft and bearings can be exposed to liquids without
> . being damaged. Many sellers have this item.
> 
> The above pumps are centrifugal.
> 
> This one is dual interlocking gears, which I think might be better for
> producing higher pressures for the restricted flow of a spray system:
> 
> . http://www.ebay.com/itm/280929962685? $11
> . It is quite small, but if it really is immune to corrosion, then
> . two or more could be used, since they are so inexpensive.
> . Multiple sellers have the same item.
> 
> . http://www.ebay.com/itm/250810139654 $29 + $43
> . Another gear pump, with no motor. The pipe fittings could be tricky.
> . Up to half a litre per minute, which is rather small. Maximum
> . pressure is 75 pounds per square inch, which is very high.
> 
> Searching now on:
> 
> Iwaki pump
> 
> . http://www.ebay.com/itm/350587388542 $25 + $47
> . One only, Iwaki bellows pump 220VAC.
> 
> . http://www.ebay.com/itm/140813153579 $90 + $48
> . Extra high pressure Iwaki pump with magnetic coupling arrangement
> . clearly shown in photos. Comes with useful-looking hose fittings.
> 
> There are many more Iwaki magnetically coupled pumps costing more than
> $100. I guess there are lots of now-obsolete photographic processing
> systems being broken up for parts.
> 
> - Robin http://www.firstpr.com.au/pcb-diy/
> 
> 
> 
> 
> 
> [Non-text portions of this message have been removed]
>