Which Legal Compressor has the most power?
 

Is the new 2012/13 compressor VIAIR 00090 better than the older compressor. From the specs it seems that the new one puts out more air but has a lower duty cycle but I may be wrong. Any ideas on which one is more powerful?

Re: Which Legal Compressor has the most power?
 

I would agree with although when I was on the team we use the Thomas air compressor. The VIAIR has the better flow @ 1.03 cfm vs the Thomas which has 0.80 cfm both at 0 PSI. I am however not sure about the duty cycle of the compressor because Thomas spec sheet does not specify. From what I have read I would say the new compressor would the better of the two choices.

Re: Which Legal Compressor has the most power?
 

I can't attest to the specs of the compressors, but I can say that from our experience the new compressor does seem to heat up a lot more than the old one did.

We've actually had several occurrences where the air from the compressor heated up so much (as a result of the compressor getting hot) it actually melted the pneumatic hose and caused it to burst. Eventually we mounted one of the 120mm fans from the KoP to blow over the compressor and we haven't had any further problems with it.

Re: Which Legal Compressor has the most power?
 

From my understanding of the specs of both compressors, there are a couple things to consider.

My numbers might be off by a few pounds, but the concept is correct.
The VIAIR is faster coming up from 0 to 90psi than than Thompson, but the Thompson is faster from 90 to 120psi.

So how does this apply? If your system is cycling the compressor on and off a lot, the Thompson might be a better fit for it. Otherwise the weight savings from the VIAIR make it a winner.

Re: Which Legal Compressor has the most power?
 

We used the 2012/2013 compressor last year and cooked it. They get very hot if you run them constantly. With all the pneumatics we had last year it could barely keep up (just for reference we used two solenoid breakout card and had four volume tanks). Works great for low duty systems and works great for heavy duty systems as long as you keep it cool

Re: Which Legal Compressor has the most power?
 

You might be right I don't have as much experience with VIAIR other than its spec that I have read.

Re: Which Legal Compressor has the most power?
 

I must say I agree as I have accidentally burned myself when testing pneumatics with the new compressor.

Re: Which Legal Compressor has the most power?
 

This is a repost, but it applies to the topic:

Here's a test that was run on the same system/same fully charged battery/different compressors.
System held pressure for 5 minutes after test.
Thomas 405ADC36/12 (from 2009 kit)
VIAir 90 (purchased through AndyMark)

Ambient temp: 68 degrees
Humidity: 50%
Altitude: 65ft above sea level
Volume (including hoses/tanks): 360 cubic inches
Battery voltage at start was 13.6v. During compression the voltage was ~12.4v (+/- .1v). At the end voltage was 13.02 for both.

-----------Thomas --------- VIAir
Time --- psi/temp ------ psi/temp
0 min ----- 0/68d ---------- 0/68d
1 min ---- 60/70d --------- 30/69d
2 min ---- 85/71d --------- 60/72d
3 min --- 110/74d --------- 80/73d
3:31 ---- 118/74d (cutoff)
4 min ----------------------- 100/83d
4:31 ------------------------ 118/85d (cutoff)
__________________

Re: Which Legal Compressor has the most power?
 

All things considered, it looks like the same amount of energy was disapated to reach cut off.
The Thompson did it 25% faster.
The VIAir weighs considerably less.

So, there is your compromise: Weight or Speed.

Re: Which Legal Compressor has the most power?
 

For small systems it might not be a problem, but with extensive use compressor temperature might need to be taken into consideration also.

Temp and in particular the long-term damage and increased failure rate due to running either of the compressors outside it's spec. might also be an issue with repeated usage. For instance, pre-charging a large system, 5 min brief rest, 2:15 match use, 45 minute rest, repeat.

As I recall the second run of the VIAir after a 45 minutes rest, took it's case temperature to the mid-90's, mostly because of the longer run time required. The Thomas 2nd run was mainly lower because it finishes sooner.

Re: Which Legal Compressor has the most power?
 

Note the Viair compressor is only rated for use with a 1 gal (231 cubic inches) while your test is with it filling a ~1.5 gal tank.

Where did you take those temp readings. The Viair has a head design that will be much more effective at pulling heat from the compression chamber and dissipating it. What was the temp of the heads say 1 min and 2 min after shut off?

Re: Which Legal Compressor has the most power?
 

I assume the intent was to use a real world scenario, not all robots have a 1 gallon combined tank volume. Also, from an electrical perspective, motor heat would be more important (although melting seals would probably be counterproductive).

Re: Which Legal Compressor has the most power?
 

Also note that the new VIAir compressor needs a relief valve "tee-ed" off the start, which does add a little more weight.

Re: Which Legal Compressor has the most power?
 

Does the VIAir compressor need the check valve or can it be left off?
Thanks for all the help,

Re: Which Legal Compressor has the most power?
 

It MUST be there regardless of which compressor you use. Read R86.