Small and Cheap HPA compressor

[THE JEW (RaVeN)]

Well, a timer is $10 so I'd front that

Cubic Inches of interior volume x 3 = number of minutes to fill that tank to 4500 psi or 300 bar

No need for special valves. Just set the timer. 2/3 of that for 3000psi. 1/2 if you're conservative.


4500psi = 50% more shots per same volume. For all intents and purposes, you get 50% more shots at the same weight/volume. I prefer 4500psi because then the compressor can do BOTH.


I was not aware of the free hooker and blow option. Please select it from the drop-down menu when ordering. Thanks.

[[PX]Kal Bob]

Not sure if I trust the timer option lol, the boom factor is concerning.

[THE JEW (RaVeN)]

*shrug*

We dive around metal, rocks, and buildings holding the tanks under our arms.

Double timer it if it's really a concern.

[[PX]Kal Bob]

Looked up the maintenance instructions.
It says to lube it up after 20 hours run time. So in our case, daily.

[[PX]Kal Bob]

Ok so things are moving along nicely with this idea.
There has been alot of talk and a lot of interest in the compressor so here is the nit and gritty:

Total cost with Shipping to Port Huron*
Compressor + Hardened Pistons + Maintenance Kit + Shipping 618.54
Port Huron Pickup Charge 5.00
Total 648.54

Minimum Spilt Number 8:
Costs at 8: 82 Dollars per person.
Cost at 10: 65 Dollars per person.

So as you can see more people = better lol
So if anyone else is interested and if you own HPA you should be lol. Please let us know.
I will be printing off this info at the next few events to let people know about it.

Timeline: We could order right away, but I think it is best to wait until the new rules kick in for the amount you can bring over the boarder.
Ideally I think we should wait until the first week of June. Queen and I have a trip to Washington planed and we will be gone for a Week+.
Thus I could bring the whole thing back Tax Free.

Ok as for the discussion on the weekend, I have the following people interested in splinting on the compressor:

1. KalBob
2 .IronFist
3. Jew Raven
4. Thumperup
5. Dave S.
6. Dempsey
7. Nebuchadnezzar
8. TSB **

I could have sworn there we 2 more interested people but I can't remember.
Please post here if you are interested in getting in on this.

* I looked up direct shipping to canada, 138 dollars was the cheapest available. Since there is no duty on U.S. made goods we might only get hit with taxes.
** Need confirmation.

[THE JEW (RaVeN)]

This is for the chain-driven model I presume? I think TSB was also interested.

[THE JEW (RaVeN)]

Belt driven difference:

Single stage reduction, extra quiet, no maintenance or lubrication.

http://www.shoeboxcompressor.com/new-options.html

Seems to just be noise and no adjustment of the chain (ie. tightening, lubing, etc.)

I, personally, would rather have the chain version (ie. cheaper) and used the saved money for the hardened steel option. I think chain is less likely to break and likely easier to replace rather than a special belt.

[[PX] Nebuchadnezzar]

officially in.

[THE JEW (RaVeN)]

Shoebox FAQ before it was released. Older, but some still relevant, info:

http://www.automags.org/forums/showthread.php?t=251312

[THE JEW (RaVeN)]

Pretty sure I found the Viton O-rings:

O-Rings for Straight Thread Tube Fittings

Also known as boss O-rings, use these as replacement O-rings for SAE high-pressure straight thread tube fittings.

Viton® fluoroelastomer is used in applications requiring chemical and oil resistance. Temperature range is -15° to +400° F. Durometer hardness is A90. Meets ASTM D2000/SAE J200. Color is black.

Depending on the size, they're $3-$15 for a pack of 25 from McMaster-Carr.

EDIT:

Searching for "boss o-ring" on the site pretty much brings up what I think we need. We just need to lock down the sizes/specs. Either way, I'd be willing to bet a package that they'd work.

EDIT2:

Tom says it's this:

urethane 90 durometer size 006

http://www.shoeboxcompressor.com/forum/ ... age-******

Also, from that thread:

Have you tried PTFE for the two main shaft sealing rings? They are a little harder (Shore D:55) but they have better lubricity, excellent abrasion resistance, less need for lubrication, high temperature and pressure ratings, and so on. They are also cheaper. They may be a little too hard for the back check valve, but if they work for the other two it could save you parts and might even be better. If you have already tried these for those two parts then nevermind

Tried them before and they didn't last but we are experimenting again with different parts.

tk

[[PX]Kal Bob]

Right now the price is Stock Chain Drive 4500psi with the maintenance kit.
If we can find a supply of O-Rings that are cheaper then the repair kit, we can do that instead.

I was looking for numbers on the improvement gains with the hardened rods, but I could not find anything definitive.

[THE JEW (RaVeN)]

I've fired off an email to ask about its advantages.

[THE JEW (RaVeN)]

The legend himself got back to me.

My Question:

Hello,

I'm debating purchasing a Shoebox compressor and I've noted that you have a piston upgrade:

Hardened pistons
SKU: 435

Found here:

http://www.shoeboxcompressor.com/Upgrad ... u.tpl.html

What is the advantage of these pistons over the stock ones? Reliability, durability, etc?

Thanks,

Jason

Tom's Answer:

Hi Jason,

If your going to use the Shoebox to fill large scuba tanks the hardened pistons are smoother and will stay that way a long time. This increases your oring life and time between maintenance. If your just filling say an air rifle once a week then the hardened pistons are less of advantage. Its for guys that work the heck out of the compressor.

Tom

[[PX]Kal Bob]

So it sounds like the pistons might be the way to go.
Only 25 dollars, and with the pricey O-Rings, might pay off quick.
Thoughts anyone?

[THE JEW (RaVeN)]

I agree. My ideal config would be:

1. 4500psi unit (fills both 3000 & 4500)
2. Chain driven (cheaper)
3. Hardened steel (reliable)
4. Maintenance package
5. Install T with valve and 3000psi burst disk (safety)
6. Electric timer (safety......can do 2 in series if considered warranted)