Why No Foot Pumps for PCP's?

[MJS]

Foot pumps are much easier to use than hand pumps, and with a larger cylinder (or multiple cylinders) they could easily fill a PCP with fewer strokes.

Anyone know of a good reason why there are no foot pumps designed for PCPs?

 

[Metalmaniac]

One reason is you need high pressure with a reasonable amount of volume. That means a small diameter bore / piston with a long stroke for volume.
If you bend your knees keep your arms straight and push with your upper body weight. Pumping with a conventional pump is easy 3000 psi or less on 250 to 300cc resivors.

 

[dizzums]

i saw a guy on youtube make a rig out of wood and levers he hooked to a bicycle chain and drove the pump action by peddling heheh ..

 

[MJS]

I've used a hand pump for 5 yrs. and just thought about building a better mouse trap. We'll see.

 

[silvershooter589]

Maybe the same reason a lot of other things aren't being built...someone just needs to do it. On the other hand it might be difficult to get a long enough stroke.

I have wondered this too, thinking a foot pump would be way easier. Especially for a 200 lb guy like me. If it was priced comparably to hand pumps, I'd purchase one immediately.

I think you could get a plenty long stroke by not simply having the piston go vertically down under the foot. It should function more like a mountain bike rear suspension, with linkage so it's able to produce more travel.

Heck, you could even rig one up with adjustable spring/damper (for your specific weight) and you could lightly jump on it like a spring board for a few minutes to fill up your gun.

 

[delooper]

IMO incorporating the pump into a home gym would be the way to go. I'd like to see rowing machines and stationary bicycle pumps.

My impression is the problem with simply piggybacking such a rig on a hand pump is the hand pump would overheat too quickly. So you'd want to maybe merge the gym equipment with a more substantial pump -- like a cheap electric pump. Something where there is enough metal "meat" so that you could more effectively cool the pump.

 

[MJS]

Maybe something like this but built for high pressure and has a foster connect.

 

[BackStop]

Maybe something like this but built for high pressure with a foster valve:
View attachment 278565

One reason is you need high pressure with a reasonable amount of volume. That means a small diameter bore / piston with a long stroke for volume.
If you bend your knees keep your arms straight and push with your upper body weight. Pumping with a conventional pump is easy 3000 psi or less on 250 to 300cc resivors.

I think Metalmaniac hit the nail on the head for why you will not see a high pressure foot pump.

Compressors do it with a much shorter stroke, but a much larger piston which moves much faster and with more force.

So, for a short stroke HP foot pump, you would have to do the same and my guess is it would not be fun or better than a hand pump. I doubt it is even possible.

I have blown a 4500psi burst disc using a hand pump and it wasn't hard at all. Yes, the reservoir was small, but I was only topping it off, the same as I would have done with a larger reservoir.

It all depends on how large the reservoir is and how far down you take it before pumping it back up.

Certainly, hand pumping a large tank/reservoir from empty or very low pressure can be a chore.

However, once it is full, topping it back up with a hand pump is easy unless you take the pressure down a lot, which also points to the need to tune your airgun to use air as efficiently as possible!

So, for smaller calibers like .177 and .22, hand pumping isn't really a problem unless you like to shoot long sessions before refilling.

With my Fortitude and DAR in .177, I can shoot 30 rounds and pump about 30+ times or 60 rounds and pump about 60+ times. The DAR uses more air (850fps vs 750fps), so it takes slightly more pumps.

30+ pumps takes about 3 or 4 minutes from the time I take out the pump until I put it back up.

When you get to the higher calibers and like to shoot a lot, then a compressor may be something you need.

 

[beerthief]

you would have to jump on a foot pump both feet . a mater of physics.

 

[BackStop]

you would have to jump on a foot pump both feet . a matter of physics.

And even that would probably not work.

 

[Ezana4CE]

I’m far from an engineer but my thought is that many of us would still have to walk after a fill. Hand pumping is exhausting for many, especially approaching 4000 psi. Imagine your legs and hips feeling like your upper body feels after being tired from using your core, arms, and shoulders to pump high pressure air. Your leg muscles may start cramping on that walk back to the bench or out into the mountains, pasture, or woods. Personally I’d hate to deal with cramped hamstrings or calves and have a ways to go to get to my vehicle and a substantial amount of gear to haul with me before leaving, especially if I have pretty full backpack.

 

[Str8tshooter]

Pogo would be more fun.

 

[d3vnull]

From a structural perspective the amount of non-vertical force you would apply on a foot pump would require a substancial amount of reinforcement at increased cost

Even the cheap tire inflation foot pumps often bend with to much side force.

 

[Dr. Kralenstein]

There was a hand pump I seen on GTA that was modified to have a lever handle so you could pump it like a well or drum pump. Made it way easier and able to do it with one hand at a time.
Of course I can't find the thread or picture of it now, but I remember thinking wow that a great idea to have for a back up fill source. I hate hand pumping.

 

[BackStop]

There was a hand pump I seen on GTA that was modified to have a lever handle so you could pump it like a well or drum pump. Made it way easier and able to do it with one hand at a time.
Of course I can't find the thread or picture of it now, but I remember thinking wow that a great idea to have for a back up fill source. I hate hand pumping.

The Shoebox compressor (not sure if it is still available new) essentially took 2 hand pumps and combined them with a motor and a standard oil-less air compressor for pre-compression.

It had a following and those that own(ed) them swear they were great!

 

[badger5th]

Maybe something like this but built for high pressure and has a foster connect.
View attachment 278565

Hmm, I'm sure it could be done. As I see its effectiveness would depend on how much weight you would have to shift onto the pumping foot. Could be unstable once you get over about half your body weight. The hand pump operation is symetric and anatomically stable.

 

[Dr. Kralenstein]

Something like this. Don't mind my 3rd grader doodle, you get the idea!

Make a frame out of 2x4s and mount the pump to it, you stand on the legs of the frame and pump up and down. You could add a mount to hold the gun too.

 

[BackStop]

WOW!

The way some of you are complaining about hand pumping, I am surprised you can even hold up the airgun to shoot it! (friendly chuckle)

 

[Dr. Kralenstein]

WOW!

The way some of you are complaining about hand pumping, I am surprised you can even hold up the airgun to shoot it! (friendly chuckle)

I bench 355, squat 490, and deadlift 545. I'm obviously in decent shape and I HATE HANDPUMPING.

Try hand pumping a 4250 psi 500cc bottle and get back to me on that!

 

[BackStop]

I bench 355, squat 490, and deadlift 545. I'm obviously in decent shape and I HATE HANDPUMPING.

Try hand pumping a 4250 psi 500cc bottle and get back to me on that!

Wimp! (chuckle)

Go back and really READ this thread this time.