Prototype bicycle compressor

Hello,

I am trying to build a prototype which needs to have a compressor as one of the parts. I want to mount a compressor to a bicycle wheel (the wheel being the prime mover) So I need the compressor to be either a vane, screw or gear pump/compressor.

Gears

It will need to be light and cheap structurally (hopefully plastic).

I am wondering if I can use an existing pump like an auto fuel pump or something like that to compress air. It would seem as long as the pump is positive displacement I would be able to compress air with it. What is your thought on this?

Thanks,

Rodney

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Bill stumbles with a reply…

Hi Rodney….whew, very interesting issue. Glad you took the time to write in.

The issue, as I see it, and one that I don’t see the answer to in your question is, how much air at what pressure do you need to generate with the bicycle driven compressor?

Can you use a positive displacement pump as a compressor? Sure.

Can you drive the shaft of that pump from any rotary drive source (including a bicycle wheel)? Sure.

I don’t have any concrete suggestions except that you need to narrow down flow and pressure requirements to help determine whatever style of compressor you ultimately decide on.

Anyone out there have any thoughts for Rodney?

Can you, or do you fix compressors?

I get what seems to be a never ending stream of inquiries (that’s OK, I am not complaining) from mostly DIY type folks looking for help to get their compressors fixed.

So many, in fact, that I’ve created a page on my website dedicated to providing sources of compressed air repair facilities around the world.

My compressed air information website gets more than 500 unique visitors every day! A lot of these people are looking to find information about getting their compressor repaired.

If you fix compressors of any kind, please visit the repair page and post your information. Tell folks what you do, what specialties you have if any, and in particular, if you would welcome customers with one of the (maybe millions now?) huge number of home compressors that are in use at home, in small workshops and garages. There is no cost involved to post your information.

Here’s where to post your info.

Unloader valve question…and response.

Porter Cable 5hp., 60 gallon.

The unloader valve hisses air while the compressor builds pressure, then when cutoff pressure hits, it unloads, and the leakage stops.
I really haven’t noticed this before.Is this normal?

Bill answers…

Howdy;

In a word, no.

Your unloader valve should be closed when the compressor is running, allowing all of the air being compressed to be sent down to the tank, and not bled out of the unloader valve.

When the compressor reaches the high pressure cut-out, the pressure switch reacts to that high pressure point, shuts off power to the motor, and then opens the unloader valve to unload the compressed air trapped over the piston.

It does this to help the compressor start more easily next time the low pressure trips the pressure switch to start the motor. If there was air trapped over the piston, the motor would have to work a lot harder to start against that load.

In your case, it sounds as though you have a seal leak of some kind in the unloader valve.

Getting a home compressor fixed

There are a host of brand name and off brand compressors available for the home workshop these days, and the price deals are almost incredible.

Being electromechanical in nature however, eventually a compressor will break down. When that happens, what is the compressor owner to do, when so many of the shops that sell compressors do not repair them?

I get many questions from visitors to my compressed air information website asking about this subject.

So, I’ve put up a page on that website that is asking companies that repair compressors to post their information, starting with their city, state and in some cases country, to make finding a compressor repair depot where you are easier If your company fixes compressors, why not take advantage of a posting (no cost) on a compressed air website that gets more than 500+ unique visitors every day?

If you are looking for compressor repair, visit the bottom of that same page to see the existing listings. Perhaps there is a compressor repair depot already listed for where you are?

Need a new compressor?

5 hp.

Model 58185B

5Z185B1

Serial D31892

#264855

Piston cracked and damaged the block.

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Bill answers…

Howdy.

Piston broke, hmmmm?

Yeah, I been that way too!

(Sorry, I just couldn’t help myself!)

The where you buy a new compressor depends on a lot of things.

• -where you are in the world
• -what resources in computer supply you have close enough
• -whether the 5HP unit was doing the job for you
• -whether now that you need a new one do you need to upsize
• -what voltage you have available to run a compressor

…and so on.

Answer some of these questions and you’ll be well on your way to selecting the source for your new compressor.

Check out  this page on buying a compressor. It’s a good place to start.

Cheers,  Bill

Do you fix compressors?

I get a ton of questions on my ASK page about where to get compressors repaired.

If your company fixes compressors, why not offer your services to the hundreds of folks that visit my compressed air information site every day?

Post your compressor repair service contact information here.

A pneumatic wedding….?

What the heck is this about?

Nothing to do with compressed air at all folks…maybe a little hot air.

My wife publishes a wedding information website, and I said I’d give her a plug.

If I spell the URL right, here it is!

Cheers,

Bill

Air Compressors In Harmony

It might not be opera, but you know what you like. Air compressors run most economically when well maintained, in their highest-efficiency operating range, and at their lowest design pressure.

In an ideal system, all but one compressor will be fully loaded or turned off, and the combination of compressors will be the one best suited for the current load.

But few facilities have the luxury of an ideal compressed air system. They tend to grow as production is added and changes, and depend on funding, capital and real estate.

More on this excellent article from Plant Services… right here!

What’s a 2-2 Air Valve?

2/2 Air Valves;what are they and how are they used?

If a compressed air valve is labeled as a 2/2 air valve, that designation assumes the following about that valve

~ it has two open ports (an in and an out air line fitting port)

~ it can be shifted into two positions

~ it is normally open (NO) or normally closed (NC) in its un-actuated, resting state

When an air valve is not being actuated by an electric or manual or internal operator, or when someone isn’t pushing the button or moving the valve’s lever, it is normally referred to as being “at rest”.

Here’s more info on 2-2 air valves.

About compressor size and plumbing a compressor…

“Im building a vehicle maintenance with four bays. My required compressor pressure is 250 psig. What size of the compressor must i buy? What size of pipe to run the system. Can you give me a hint or formula in solving the capacity of air compressor and the pipe. Thanks”

______________________________________
Bill answers…

You need to work backwards from your applications to determine how big a compressor and how to properly plumb it.

How many air tools will potentially be run at the same time in your shop, and what is the accumulated demand of these air tools in CFM and pressure?

After you have determined your demand requirements, then head back to this website, and start here regarding plumbing your shop.

You will want to take a look at these pages about pressure drop as well.

Everything else you will need about sizing and plumbing your compressor you will find on this website.