Other legal compressors this year

[Rob Colatutto]

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

[scottydoh]

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.

[monty1540]

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.

[Vikesrock]

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.

<R75> Compressed air for the pneumatic system on the ROBOT must be provided by one and only one compressor. This compressor may be either the Thomas Industries compressor from the KOP, or an equivalent compressor that does not exceed any of the KOP compressor performance specifications (specifically: 12v, 0.8cfm flow rate, 120psi continuous pressure, 120psi maximum pressure compressor). Note: if an alternative compressor is used, during inspection the team may be required to provide documentation to show compliance with the performance specifications. Compressed air shall not come from any other source. The compressor may be mounted on the ROBOT, or it may be left off the ROBOT and used to pre-charge compressed air in the storage tanks prior to bringing the ROBOT onto the FIELD. Off-board compressors must be controlled and powered by the ROBOT.

[Rob Colatutto]

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>

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.

[Mike Betts]

Kevin, et al,

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

Forget I chimed in...

Mike

[sdcantrell56]

I am really liking this compressor from viair :
http://www.cheaptruckparts.com/product_info/category_id/7/subcategory_id/154/subcategory2_id/13/subcategory3_id/69/products_id/27201/?PHPSESSID=e538c34f59a8ebd95be745a968a60d18

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

[Vikesrock]

I am really liking this compressor from viair :
http://www.cheaptruckparts.com/product_info/category_id/7/subcategory_id/154/subcategory2_id/13/subcategory3_id/69/products_id/27201/?PHPSESSID=e538c34f59a8ebd95be745a968a60d18

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

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".

[EricH]

I am really liking this compressor from viair :
http://www.cheaptruckparts.com/product_info/category_id/7/subcategory_id/154/subcategory2_id/13/subcategory3_id/69/products_id/27201/?PHPSESSID=e538c34f59a8ebd95be745a968a60d18

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

[monty1540]

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/workareashowcontent.aspx?id=21654

[Stephen of REX]

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 (http://www.cheaptruckparts.com/product_info/category_id/7/subcategory_id/154/subcategory2_id/13/subcategory3_id/67/products_id/27196/?)
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.

[RyanN]

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 (http://www.cheaptruckparts.com/product_info/category_id/7/subcategory_id/154/subcategory2_id/13/subcategory3_id/67/products_id/27196/?)
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.

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.

[Racer26]

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

[martin417]

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.


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

[sdcantrell56]

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.

[MrForbes]

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

[Stephen of REX]

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:

[martin417]

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.

[MrForbes]

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.

[Homsar66]

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.

[Stephen of REX]

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

[Racer26]

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

[Homsar66]

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

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

[MrForbes]

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? :)

[Racer26]

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.

[Stephen Kowski]

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?

[Racer26]

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

[Stephen Kowski]

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

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.

[Racer26]

Ah... well then. Any alternatives?

[Don Wright]

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

[Jeff Waegelin]

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.

[rocknthehawk]

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.