SMALLSMT Vision Placer Pick & Place machines

[mrpackethead]

How critical is the 110 litre/minute specification for the VP-2500DP?

Just attempting to answer this from experience with another P&P, the specification is usually a theoretical maximum that you will not encounter often for longer periods (if at all) and your buffer tank smooth out any mismatch between compressor and P&P. E.g. the vacuum on the nozzles will not be on all the time, the nozzle's will not have component all the time, your feeders are not constantly using air etc.

Our compressor -in theory- is barely able to supply enough for our P&P as well but in practice the duty cycle of the compressor is less than 50% when the P&P is working at full-speed.

This is my experience as well.   My Yamahas claim they need 300L/min, but in fact with 3 machines running, i run about 25% with a 1100L/min compressor.    I am not sure what the SmallSMT machiens need, but dry air is normally really important for machines with solenoids.     

[Kjelt]

If the peak flow is too high for the compressor but the average flow is in the range for said compressor you can place an extra storagetank close to the P&P machine, as long as its pressure is equal or a little bit less than of the compressor (so before the pressure regulators of the p&p machine) you will relieve the compressor. It works like a capacitor in electronics.

[SWR]

According to Michaels reply the flow rate is not super critical.
I don't mind that the compressor runs while the P&P is operating.
It's a low noise 60dB type and I expect more noise from the P&P.
I will place the compressor right under the P&P so the 6L tank will work as a buffer.

[SMTech]

Not that critical maybe but a compressor with a 6L tank must be miniscule.
 Our Essemtec requires 60 or 120nL/min depending which datasheet you are reading at the time; that is connected to an SIP compressor rated at 300 Litres/min with a 100Litre tank, in between is a regulator and a dessicant air dryer&filter unit, the dryer on its own user 20Litres/minute. The duty cycle is somewhere around 30-50% and that is about as high as you want the duty cycle to be, any higher and you will kill the compressor pretty quickly. To avoid that you need to buy a screw compressor, much quieter continuous operation and a consistent pressure output but they are super expensive.

[Kjelt]

Exactly, the lower cost compressors can not run all the time for a prolonged period of time, they overheat.
That is at least what my merchant told me when I bought mine two cilinder 2,5kWh 100l tank compressor for €700, this is still not suitable to be used continuously with certain airtools that need too much air.

[mrpackethead]

Exactly, the lower cost compressors can not run all the time for a prolonged period of time, they overheat.
That is at least what my merchant told me when I bought mine two cilinder 2,5kWh 100l tank compressor for €700, this is still not suitable to be used continuously with certain airtools that need too much air.

Yup, you get what you pay for. Buy an elcheapo made in  cheap air compressor and expect it to run at a professional level, then your being unrealistic and will be dissapointed. Much like buying PNP machines.

[SWR]

Yes, I might need to upgrade the compressor.
This one was cheap ($99) and more importantly quiet (60dB).
The sales ad said 8bar 150L/min but I have a feeling that the 105L/min in the back section of the manual is the real number.


On the positive side it is indeed very quiet.
My larger compressors are too noisy to have inside the house.
This one is just for the pick & place.
If it doesn't cut it I'll have to find a larger one.
I can get accustomed to the low noise level very quickly though.

[Kjelt]

What I am now thinking about, is the l/min requirement not pressure dependend?

[SWR]

Yes, it was also the 110L/min requirement I was worried about if the compressor only gives 105L/min, but according to Michael it is not super critical to have exactly 110L/min.
Maybe I can run it at 90% or 80% speed if it becomes a problem?
Otherwise I'll just have to suck up the loss of $99 ... I'll grit my teeth and take it! 

[Kjelt]

I just wondered since (stupid example but hey ) when I use my airgun to get the BBQ going on 4 bar the compressor will start after 5 minutes or so, but hen I use it at 1.5bar it takes a lot longer. The airflow presumably is the same.
Maybe I make a mistake, I am on an ipad in a foreign country with 0,5Mb/s internet so can't do research but just thinking that if the P&P requires that flow at 6 bar and your compressor delivers 10 bar it might change the picture.
BTW my compressor is 80dB+ or so, so I stuck it in the attick of the garage and used 25m pressure hose to my service points. No problems with the noise, could also be an alternative.

[SWR]

Thanks for the suggestions.

I was thinking to set it at 6bar cut-in and 8bar cut-out.
The compressor will have to supply the amount of L/min the P&P is removing - otherwise the pressure will slowly but surely drop.
According to Michael the 110L/min spec. was set at 30% compressor duty cycle.
If I can keep the dutycycle below 60% it has a chance to cool down and I'll keep it.
Otherwise I'll have to find another solution.

[Styno]

Or buy a second one and run it with a master/slave switch from the first compressor. Two compressors and twice the buffer capacity. 100 bucks is a steal...

[Smallsmt]

Don't forget to order a water separator



Here some examples for air compressors

https://www.ebay.co.uk/itm/241184-ORAZIO-Low-Noise-Oilless-Silent-24L-Air-Compressor-800W-Garage-Clinic-/282084042569

https://www.ebay.co.uk/itm/Titan-Precision-22L-Silent-Quiet-Dental-Medical-Clinic-Oil-Free-Air-Compressor-/302941915256

[mrpackethead]

Don't forget to order a water separator



Here some examples for air compressors

https://www.ebay.co.uk/itm/241184-ORAZIO-Low-Noise-Oilless-Silent-24L-Air-Compressor-800W-Garage-Clinic-/282084042569

https://www.ebay.co.uk/itm/Titan-Precision-22L-Silent-Quiet-Dental-Medical-Clinic-Oil-Free-Air-Compressor-/302941915256

These only really work to a point, if your Humidity is over 70% then you really need a refridgerated air dryer.     When air is compressed it gets hot, and will hold a lot of water, As it runs through the tank/line etc it cools down, and the water precipiates out.    ( much like rain/clouds ).      Water is really good at damaging delicate pnuematicly operated devices.

[IconicPCB]

On the issue of drying air... some of it is possibly achieved by runing air supply through an inclined line such that water drains back toward the compressor... this of course implies a water trap ( as shown above )  at the compressor end of the hose.

[mrpackethead]

I get about 1.5 -2 liters of water per hour out of our dryer, when we are running both PNP machines.    The dryer i have is simply a refridgerator..

[Kjelt]

Where is the pressurized air used in the smallsmt machines.
Do they have pneumatic heads ?
If it is only for the venturi vacuuum generator it is not that critical ?

[mrpackethead]

Not sure if its only vacumn or if it also 'puffs' a little bit when the part is placed.  Lots of parts will stick on the nozzle and you need some postive pressure to push them off.

[Kjelt]

Makes sense.
A decent aircooler will cost hundreds of $ though.

[mrpackethead]

If not thousands.. However a very DIYable project for someone if they so deisred.  They are not at all complex.  But wet air will cost me tens of thousands of damage, if i had to replace the heads!

[IconicPCB]

From whay I understand of smallsmt requirement air is used for
vacuum generation,
feeder activation
and blow off of components.

[Smallsmt]

From whay I understand of smallsmt requirement air is used for
vacuum generation,
feeder activation
and blow off of components.

Yes, that's exactly right!
We have to avoid drops of water which will disturb the function of the machine.
Water drops disturb the function of the Venturi nozzles and reduce the generated vacuum.
If no water trap is used, condensed water can cause this effect.
The machines are not so sensitive that dried air is necessary.

[Smallsmt]

Where is the pressurized air used in the smallsmt machines.
Do they have pneumatic heads ?
If it is only for the venturi vacuuum generator it is not that critical ?

We use for venturi vacuum generators and CL feeder / push feeder control.

[SWR]

Thank you for the links.
These compressors looks identical to mine when looking at the compressor part itself, but with bigger buffer tanks.
I assume that mine will run shorter with a 6L tank but more often.

This is the $29 water seperator I bought and plan to mount to the back of the VP-2500DP:


Best regards
Soren

[mrpackethead]

Its completly your choice if you dry your air or not.   Since i have many tens of thousands of dollars of Yamaha CL feeders, with accuators on them that have air quality specifications, i'll use a proper dryer, so they continue to operate properly.      THose water traps will catch any water in the line that has condensed out. It wont' remove the moisture that is in the air, which will condense on any cold ( relative to the air temp ) surface. 

If your equipment manufacturer advises that it is not a requirement to use a dry air source, make sure that they will cover any warranty issues due to wet air damage.