Ceres Hardi

I’ll add my two bobs worth on al the taps on the tanks or pump. Leading to the outside put a two inch male camloc fitting and get a length of that grey suction hose to hook up to any of them good for filling or if you want to empty any excess you can run it out into a shuttle

Buey

Well not a lot to report 

Gumpy it's plastic reinforced suction hose

Bluey amother good idea, thank you

I was pretty confident it was gunna be all systems go, well I am a fool

Everything went.as expected except for the pump
It (the pump) will build pressure but won't maintain it 
it pumps fine but not under pressure 
For those of you that have never done spraying before I will briefly explain 

The mixture of chemical is mixed with a measured amount of chemical to water
This ratio is worked out using the 3 following things

a) speed to be travelled
b) pressure you are putting the chemical out 
c) application rate (probably not the correct term)

So I  need a constant pressure, this means I have a measured volume leaving the jets

I need to travel at a constant speed 

Once I have these two I can then work out how much liquid is going to be applied per hectare or acre

When thats worked out I can then make the mix 

Now this all gets a bit confusing, certain plants at different stages of growth require more or less application rate 

Growing mung beans and they are getting big requires big volumes of water to get enough chemical on to do the job

anyway the pump builds pressure but won't mantain pressure 

Been a diaphragm pump it has no return valves and diaphragms of course

So I open it up and can't find and issues

 

 

So although the diaphragms are perrished are okay I feel as there is no sign of rust on the crank end

So I  disassemble the non return valves and can't find anything wrong

So maybe the O rings are hard as it's been years since it's run

 

 

Re assemble and no real change, maybe held pressure slightly longer but not fixed

Next pressure relief valve, so pull it apart and I notice the plunger is getting stuck ever so slightly 

So a quick run around with the die grinder at it's moving fine

 



 

So run out to the farm and grab the original pump off the linkage sprayer, I stopped using it when in north QLD and because I right on the coast the wind blew all the time

I had to the sprayer up and changed to air induction jets

Bigger volume of water, halved the pressure and doubled the volume

This meant much much bigger droplet size so I could spray in 15 - 25 km wind with minimal drift 

Anyway I grab the old pump and figure it will be fine 

Oh I was dissapointed, the none return valves and diaphragms are stuffed so badly they don't even look like they should 
Anyway I  notice right away that the crank has a shorter throw




So I look harder and the linkage one is of course 540 rpm and the ute back pump is 800 rpm
Even with this the linkage unit was only just big enough 

So I I figure I best change the pump and get new valves and diaphragms as if I wanna move at a reasonable pace I need more volume per minute

 

Anyway, we will see what next week brings

Paul


 

This is probably a silly question,  but have you checked the working speed at the pump shaft?  I don't know if overspeed would cause the fault you are experiencing, but just from what i can see in your photos on page 1, it appears to me the old Delta motor has a built in reduction drive.  I might easily be wrong, but to me it looks as if the output shaft on the Delta motor is offset from the centreline of the crankshaft?, indicating an internal change of ratio of some sort.

Also hard to tell, but it appears the Delta motor runs the opposite way from the Chonda, but the internal output shaft drive corrects output rotation to be standard (same as the Chonda). 

I think the pump could run either direction anyhow, without any ill effect.

I am thinking perhaps the pump speed is actually faster than you realise/expect, but again, i don't know what affect that would have on the pumps performance.

My Chonda powered air compressor appears to have similar pulley sizes, and the engine on that chugs away quietly at only a tad above idle to run the compressor at its rated 900 rpm.

I might be totally up the wrong tree with all this Paul, i'm just thinking out loud at the moment.

Brett.

I am sorry Paul, i just read page 2 again, and yes you did mention you have reduced the engine revs on the Chonda.

PS - With my air compressor, i simply set the maximum RPM screw on the motor with the compressor turning at 900 rpm.  That way i can still idle back, but never over rev it.  So far i have found i never need to adjust the revs.

Brett.

Brett I'll check these things, but it does pump fine with no pressure so I doubt the motors out put shaft is spinning backwards
And it is just at a idle
None the less, I will have a look today
Thanks for the ideas Brett

Paul

Is there a restriction on the inlet side, not allowing the water to flow fast enough into the pump to maintain pressure, we had that problem with a transfer pump, the inside of the hose had delaminated and restricted water flow when the pump sucked , at idle or start up it worked fine then the flow slowed down and couldn’t build any head pressure.
gumpy

Well the saga continues with glimmers of hope now and then 

I got new diaphragms and non return valves and installed them and put the pump back on
no change at all, only in the bank ballance after spending money

I eventually find a pin hole in the suction hose near the pump end and shorten the hose 

 

 

Thinking finally I have actually found something 

I start the sprayer and sure enough, success




Head out bright early the next day, fill the tanks and off I go, we spray for maybe 10 minutes and the issue starts again

Back to the yard

I am getting a bit peeved with this pump and spray unit by this stage 

I swap the regulator, no change 

Suction hose, no change 

So running out of things to change

Pulled the suction hose and pipes and fully out and found nothing

Found the diaphragm in the pressure cylinder (tank that is on a pressure pump type of deal) has already failed so changed that as well, no change

Interestingly, when it goes into pressure mode of operation, the pump slowly stops pumping completely with zero bypass pumping

I dunno, gunna have to do some thinking 

Paul

 

Is something slipping on a shaft - enough friction to turn it when little load but slips when loaded.

Is there a keyway missing a key?
Gumpy