I'm attempting to build something I ran across on youtube, and could use some advice regarding whether or not a less expensive 24V geared wheelchair motor can be substituted in place of the original drive motors? I've included the original youtube project links ((see below)) for easier explanation and additional reference.

Unfortunately, I have no idea if a wheelchair motor will provide the required torque for this particular application? Also, I'm concerned that the WC's motor rpm may be too fast? "If" the WC rpm's prove too fast, I believe I "might" get lucky by reversing the voltage on the WC motor to take advantage of the slower "reverse" gear??? "If" the WC motor's reverse gear proves too fast... I'm hoping there might be a simple/inexpensive rehostat option for slowing down the rpm's(?)

Any thoughts, no matter how detailed, would be greatly appreciated!

www.youtube.com/watch?v=vs95euUkGaE

http://www.youtube.com/watch?feature=endscreen&v=q_22dphYB_k&NR=1

 

I would try to keep the speed at or about the same as pumping by hand. The rason being the pump has no cooling fins. The heat from pumping at a faster pace may not be good for the pump internals.

It would be easier to give an answer for the motor if you had included your country in your member information. Does this motor need to be run from a battery? Or is mains electricity available?

 

I would try to keep the speed at or about the same as pumping by hand. The rason being the pump has no cooling fins. The heat from pumping at a faster pace may not be good for the pump internals.

It would be easier to give an answer for the motor if you had included your country in your member information. Does this motor need to be run from a battery? Or is mains electricity available?

Agree...as the project evolves I had kicked around the thought of adding some extra passive/active cooling (ie: clamp on aluminum heat sinks/mini high volume fan) around the high heat zones. As for a drive motor, a geared "DC" wheelchair motor is my first choice due to lower cost, versatility and availability. (Plus I can take advantage of swapping in/out solar charged batteries in the field and utilize an AC/DC ps as a backup). So far, the only things slowing down the build are: 1) Finding out if a geared wc motor can power through the down stroke, and 2) Figuring out a proper rheostat/speed control circuit...if its even needed(?) I think the only way to know if the wc motor will work, is to take the plunge, order one and find out....

 

If you're getting a wheelchair motor, get the controller with it. Most wheelchairs have a joystick or twist grip speed control. Look at the resistance value of the control device, and replace it with a pot.

 

Thanks for putting in your information. Don't know how much a WC motor costs or how much torque they have, but for mains use I'd be willing to try one of these;
http://www.harborfreight.com/12-variable-speed-reversible-heavy-duty-d-handle-drill-69453.html

I'm on a metal shaping forum too, and some guys have used them to power, power hammers and other small metal shaping tools.

Where did you get the pump? I have an Airforce PCP and this might be something I'd look at building next time my scuba tank needs certified.

 

Don't know how much a WC motor costs or how much torque they have, but for mains use I'd be willing to try one of these;
http://www.harborfreight.com/12-variable-speed-reversible-heavy-duty-d-handle-drill-69453.html

Where did you get the pump? I have an Airforce PCP and this might be something I'd look at building next time my scuba tank needs certified.

Gotta love HF for all its cheap resourcefulness when it comes to tool hacks lol I actually combed HF's website for a suitable 24V/36V HD Battery operated drill and even considered a HD reciprocating drill but obviously the stroke and torque were insufficient. I never actually looked at HF's HD AC Drills...the one you listed is tempting considering price, plus it has built in variable speed and offers a keyed chuck! However, in comparison, the wc motors offer an easier, cleaner, compact, streamlined vertical mount & much lower noise output... no doubt there are tradeoff to ponder for both options(!?) To answer the second part of your reply, I recently found the pump off ebay for the purpose of filling paint ball tanks (since the closest retail fill is 30+ minutes away) now I'm set 24/7 and was even able to cancel my gym membership

 

Was combing HF's website again and ran across this... http://www.harborfreight.com/router-speed-control-43060.html. Hadn't seen this in years and thought for sure they discontinued it. It's "allegedly" good for "all" ac/dc brush-type motors up to 15 amps ACCEPT soft/slow-start motors... can't wait to pick one up and test it out... sure can't beat the price!

 

On the metal working forum, Metalmeet.com, they refer to HF tools as starter kits.

If you don't mind when you get this working would you please come back and update us?

 

sp...my bad

It's "allegedly" good for "all" ac/dc brush-type motors up to 15 amps "EXCEPT" soft/slow-start motors

 

Have you considered making the pump non-electrical? Using something like a Mantis style garden tiller and a timing belt or a #35 chain from the tiller gearbox. That way it would be totally portable into the field.

You will need to watch when attaching a heat sink to the pump too. For it to be effective it needs to be pretty tight to the pump, for heat transfer. But if too tight it might distort the pump cylinder and cause problems.

 

I was thinking lightley attached heat sinks should avoid any distortion issues...its probably overkill but if it prolongs the pump's seal life and/or allows sustained pumping it can't hurt to test out the potential benifit! And yes, I had seen a few youtube designs where someone mounted the pump to a HD frame and ran it off the pto of their farm tractor different strokes for different folks for sure! Also had seen a sprocket and chain driven version...slightly easier and less expensive perhaps but I wanted to eliminate any finger chewing potential or excessive guard fabrication. A right angle dc motor mounted on a post seems like a no brainer... quiet, compact, fewest moving parts and battery operated. A man can dream right

 

Another HF thought; http://www.harborfreight.com/2000-l...-automatic-load-holding-brake-68146-8041.html With a little fabricating, remove the drum and add a support bearing and the crank. These are on sale for around $50 in the store. They work pretty well and the speed is about right. My son has one for moving logs, so I know how good they work. And their 12V instead of 24V so only one battery needed. With the WC motor you would still need the controller to get good torque at a slow speed.

Hope you don't mind me shooting ideas at you.

 

Please keep the ideas coming!

I was going to look up surplus winch motors! Hmmm... hard to beat the HF price and I happen to live within 30min of a HF. Too bad the description doesn't mention rpm. Regardless, this could be the ticket and if rpms are too low 24v might be a possibility???

 

Just found a "lathe" based pump project on YT and was able to time the pumps rpm... looks like 23 cycles every 30 seconds... so 46 cycles/rpm give or take.

http://www.youtube.com/watch?v=H0TPVilqzQA

Also... found a couple HF atv winch winch videos on YT and I see two general issues...

1) Since the winch motor needs run the pump for apprx 110 strokes to re-fill a 2500psi tank ... I'm wondering if the winch can handle such a long run time?

2) Hard to tell by the audio in the YT videos, but the winch is seems to be noisy enough to be really annoying...grr

 

The winch is a little noisy when under full load. But the pump wouldn't be any where near the load that pulling something is. And the pump would only be a real load as it nears the ends of the strokes. The only information about the winch is that its a 1 horsepower motor and a 153:1 gear box.

The pump, I'm assuming is double acting. By that I mean on the up stroke the outer tube compresses air into the inner tube/cylinder. And on the down stroke it compresses that air a second time into the tank.

Edit: I don't think the winch my son has is any noisier than the lathe in the video.