Other legal compressors this year
 

Hello all,

We've been searching for alternate compressors that both match or beat the limits of the kit compressor, and are smaller/lighter. Has anyone had any luck finding any that fit within the rules this year, other than the kit compressor?

Any findings you all may have had would be useful, as I am sure many veterans would like to run with a smaller compressor this year.

Thanks,
Rob

Re: Other legal compressors this year
 

I was almost 100% sure any other compressor was illegal, but I stand corrected by <R75>. This is an intriguing idea, but I suspect it will be difficult to find a compressor thats much lighter than the one provided.

Re: Other legal compressors this year
 

From my previous research for a project of mine, I suggest investigating Viair compressors.

http://www.viaircorp.com/OffRoad/compressors.html

As far as I can tell some of their smaller models should fit within the maximum specifications given in <R75>

At least for the higher models I looked at for my project, google found many places to buy these compressors, and I'd guess the lower spec'd ones shouldn't be too hard to find either, but I haven't looked.

Re: Other legal compressors this year
 

Now step back forward again.

Mike, you might want to check that you are looking at the proper year's manual. That text appears to be from <R72> from 2009.

Re: Other legal compressors this year
 

Now this brings up a good question about the wording of <R75>. I wonder if at any operating pressure, the max flow needs to be less than 0.8cfm, since the flow rates are variable as the pressure inside the system increases.

Re: Other legal compressors this year
 

Kevin, et al,

Mea Culpa... I was going back and forth earlier trying to figure out what had changed...

Forget I chimed in...

Mike

Re: Other legal compressors this year
 

I am really liking this compressor from viair :
http://www.cheaptruckparts.com/produ...e745a968a60d18

What is the consensus on this? Do we think its legal?

Re: Other legal compressors this year
 

Unfortunately the CFM @ 0 PSI looks to be over the .8CFM specified in the manual, so I would have to say no.

A quick glance suggests all the VIAIR compressors may suffer from this "issue".

Re: Other legal compressors this year
 

It needs to not exceed the following: 12v, 0.8cfm flow rate, 120psi continuous pressure, 120psi maximum pressure. Plus the cost, COTS, etc.

COTS: Obviously COTS from a VENDOR.
Voltage: 12V. Good.
Flow rate: 1.03cfm flow rate at 0 PSI (under a 13.8V supply) could be an issue. It's lower at higher PSIs, but still...
Continuous pressure: Not listed that I can see. Not-so-great.
Maximum pressure: 120 PSI. Good.
Cost: Under the limit.

I'd try to find a full spec sheet for that. If none is available, I'd ask the GDC directly: We found this compressor, and we are unsure if it complies with X part of <R75>. Could you give a yea or nay?

As listed, I'd have to say nay. GDC beats me, though...

Re: Other legal compressors this year
 

You all appear to be correct, the Viair compressors are all spec'd above the Thomas compressor from the kit. The Thomas datasheet for the kit compressor shows .79 cfm @ 0psi

(Kit compressor p/n 405ADC38/12 data shown on page 4 of below link)

http://www.gd-thomas.com/workareasho....aspx?id=21654

Re: Other legal compressors this year
 

Here is a smaller compressor from VIAIR:

Direct Comparison:
Kit compressor
12v,
0.79cfm flow rate,
120psi continuous pressure,
120psi maximum pressure
COTS
cost: in the KOP
Weight: 4.3 lb

VIAIR 63C
12v
0.79cfm flow rate,
100psi continuous pressure,
105psi maximum pressure
COTS
cost: $35
Weight: 1.43 lb (Its a third the weight!)

If we ask the GDC, I'd ask about this one.

Re: Other legal compressors this year
 

It appears that the one you listed wouldn't be able to provide enough pressure to trip the 120PSI switch, and it is also not rated for 120PSI.

Re: Other legal compressors this year
 

yes, but if you can't generate 120psi, you dont need to be rated that high.

Re: Other legal compressors this year
 

Neither is the KOP compressor. Its only rated for 100 PSI, max.

Re: Other legal compressors this year
 

So for 1/3 of the weight and what looks like pretty similar specs this Viair compressor seems to be quite a cost effective weight saving means for teams using the compressor.

Re: Other legal compressors this year
 

Yeah, just be sure to buy a few extras as spares...notice the duty cycle

63C Compressor Kit VIAIR
Price: $35.00 Part Number: 00063
# 12-Volt
# Duty Cycle: 20% @ 100 PSI
# Max. Working Pressure: 105 PSI
# Amp Draw: 7 Amps
# Inline Check Valve
# Dimensions: 5.00� L x 3.00� W x 5.00� H
# Net Weight: 1.43 lbs

Re: Other legal compressors this year
 

I'm sorry, could you explain what duty cycle means? I know that it describes how long the compressor will last, but what exactly does the 20% @ 100 PSI mean?:confused:

Re: Other legal compressors this year
 

Duty cycle means the percent of time that the unit may be operated. Ifyou have 20% duty cycle, it means that in any given 10 minute period, the motor may run a total of 2 minutes. Or, out of any given hour, it may run 12 minutes. It has to do with cooling.

I wouldn't recommend running it for 12 minutes and then off for 48, it would probably overheat.

The main point is that the motor should be off about 80% of the time.

Re: Other legal compressors this year
 

Also the duty cycle rating is a rough indicator of how well the thing is made. Usually machines that are designed for long life in industrial use have a high duty cycle rating at full power, while cheap stuff has a very low duty cycle at full power.

You don't always get what you pay for, but you hardly ever get what you don't pay for.

Re: Other legal compressors this year
 

That little compressor even has a better fill curve than the thomson, It's superior at higher PSI. If only you could run two of them, then you'd be golden.
Anyway, we've got a very old compressor I was playing around with. It's about the same weight as the KOP comressor, but doesn't overheat nearly as quickly and seems to fill faster as well. Its a Gast 22d model, someone might want to check it out but i can only find 22D models with 25 PSI max on their website and that sure isn't the one I'm looking for.

Re: Other legal compressors this year
 

If it fills faster, then it is probably illegal unfortunately...

Re: Other legal compressors this year
 

Has anyone asked Q&A about this particular compressor? I would, but I'm not my team's Q&A contact.

Re: Other legal compressors this year
 

Yes, but it all depends on the fill curve. It might fill at the same rate at zero psi(.79), but fill better at higher pressures. KOP fills only around .20 at 100 PSI

Re: Other legal compressors this year
 

That's how single stage piston compressors work, not much you can do about the laws of physics. Wonder if you could find a little, light, two stage? :)

Re: Other legal compressors this year
 

Any news on this? I saw a Q&A with a non-committal answer from the GDC, with a link that I can't seem to read. Anybody know anything I don't? Saving a few pounds with a lighter compressor will lighten the weight pinch significantly.

Re: Other legal compressors this year
 

http://forums.usfirst.org/showthread.php?t=14337

I guess the answer is to make a strong enough argument....you have 2 pages worth so far anyone want to sum it all in one strong statement?

Re: Other legal compressors this year
 

Anybody planning to have a VIAIR 63C on their robot at competition?

Re: Other legal compressors this year
 

According to a woman I spoke with at viair those have not been made for several years and are not available despite what internet resellers are claiming. She said most of them are drop ship resellers that are not aware they have been discontinued.

Re: Other legal compressors this year
 

Ah... well then. Any alternatives?

Re: Other legal compressors this year
 

Any updates on a lighter, legal replacement. I haven't had any luck finding anything.

Re: Other legal compressors this year
 

I'm still looking for a lighter-weight, legal compressor... has anyone found one yet? I'd love to be able to cut some weight there for my next regional, but I haven't been able to find a replacement either.

Re: Other legal compressors this year
 

I've talked with Lance Martz, the marketing manager at Viair (I have 3 of their comps for the air suspension on my truck), and the smallest compressor they currently have is the 90 series. Unfortunately even the smallest compressor has a flow rate of 1.03cfm@ 0 psi.