i3dm

My Feedback: (51)

Hello Guys,

After having built several of these which are running with great success, i thought i'd do a build thread.
I always wanted to build a high quality fueling station, with variable rate control, reversible direction and on/off switching, so i went ahead and designed one as an integration of existing, extremely cheap off the shelf electronics.

The fueling station consits of the following parts:
1. Housing (i chose a nice aluminum box - 7$):
http://www.ebay.com/itm/3pcs-White-E...0AAOSwv0tVVY1o
If you wish to save on cost, you can use a Hitec servo box, which is free with any servo

2. Servo Tester (for rate control) - 1.5$:
http://www.ebay.com/itm/Multi-Servo-...gAAOSwMmBV5AEW

3. 5K Potentiometer (more heavy duty than the original servo tester's pot) - 1$:
http://www.ebay.com/itm/5K-B5K-OHM-L...MAAOxyx0JTewtZ

4. Heavy Duty 3 position switch (ON-OFF-ON) - 4.2$:
http://www.ebay.com/itm/DPDT-On-Off-...MAAOSwyQtVlSYB

5. Brush motor Speed control - with internal UBEC to power the servo tester - 5$:
http://www.hobbyking.com/hobbyking/s...USHED_ESC.html

6. Cap for Pot's neck (15 Cents):
http://www.ebay.com/itm/10-Pcs-6mm-S...AAAOSweW5VK2jG

Total cost: about 19$ including the fancy Aluminum Housing.
The basic principles are rather straight forward - the speed control controls the rate, and the switch reverses direction.
Im adding a sketch of the system, and some pics of the internal electronics layout and the finished product.

Assembly instructions:
1. remove the servo tester's stock pot and solder your large 5K pot on a piece of servo wire in its place.
2. remove LED1 from servo tester, and solder it back on a piece of wire. this will be mounted on the side of the housing, viewable from the outside, and will act as a visual aid whenever your battery is connected.
3. drill holes in the side of the housing to hold the pot, the switch neck and the LED, per your preference.
4. Assemble everything as per the attached sketch. for a finishing touch i added a cap on the Pot's neck.
5. Mount to your fuel tank, and Enjoy

Thanks for watching.

1Eye

My Feedback: (2)

Nice work. The block diagram comes up OK now - there was some kind of glitch before. No worries.
Oh, and I got to thinking that the use of one "slicwe" from a 3PDT On/Off/On toggle switch would allow you to keep the battery energy removed from the circuit entirely when in the OFF position.

i3dm

My Feedback: (51)

Thanks for the feedback, it does open for me, but ill attach it again just in case.

Malcolm H

Just one small point with this circuit is that the lipo will slowly discharge through the ESC unless it's disconnected. When I built one of these a couple of years ago I managed to source a triple pole double throw switch and used the third pole to disconnect the lipo in the centre position. The battery can now be housed inside the enclosure with no need for access to disconnect.

Malcolm

i3dm

My Feedback: (51)

You are absolutely correct Malcolm, the battery needs to be disconnected at the end of the flying day. this is why the LED is there to alert you whenever a battery is connected.
The problem with disconnecting the battery in the center position (or any position for that matter) is that these ESCs require "arming" (PWM 1000us signal) to start running, so after every disconnect of the lipo an arming cycle with the pot is required, this is no big deal once a day, but arming every time reverse the pump direction can become a pain.

dbsonic

My Feedback: (3)

Nicely done and documented. yeah, easy to make your own. I went caveman style and just use a couple HD SPTT switches and a 2ohm power resistor to downshift the flow.

Malcolm H

Actually I thought that was the case when I first built my unit but I quickly discovered that you just turn the pot all the way down to zero flow and from that position it will start again without rearming. Also if you reverse the direction with the switch and it passed through the off position it still stays armed and the pump reverses. At least on my particular ESC, I guess a capacitor somewhere is staying charged :-)

Malcolm

FenderBean

Your my hero

i3dm

My Feedback: (51)

lol !

i3dm

My Feedback: (51)

Here is my freshly built fueling station mounted on a new 25 Liter tank.

gooseF22

Guys instead of using the little filters, a 1/4 inch gasoline filter will work very well and last longer and let you see if any trash gets in.. its kinda like a giant festo filter.. and its a couple bucks at the store.. 6mm will stretch over the barbs.. fyi..

Nice can I3DM

i3dm

My Feedback: (51)

Good to know !
Glad i now know of these:
http://www.ebay.com/itm/10pcs-1-4-6-...BV6lC1&vxp=mtr

MarkShapiro

My Feedback: (52)

Hello i3DM,
Can you post a picot of the other side of the servo tester board so that I can see exactly where you soldered the servo wires to. Your instruction say to solder them in place of the stock pot, but which wire goes where? Thanks.

erh7771

My Feedback: (30)

Couple of questions

1. where to get the brushed pump? Also, will any of these 12v pumps for fuel work?
http://www.ebay.com/itm/NEW-UNIVERSA...5WW-1g&vxp=mtr

2. How to plum the tank and its parts, also I have no idea where to get them from... I know where to get the tank from but not the cap or the fittings or the hoses... or the.. well

Thanks for any input

LA jetguy

Very Nice setup i3dm..

Has anyone incorporated a resettable counter in their fuel station so we can see how many milliliters (fl.oz.) we pump onboard and how much we take out??

Thanks

i3dm

My Feedback: (51)

Solder the middle wire to the middle pin of the stock pot, other 2 dont matter, reversing them will reverse the pot direction of rotation.

That pump looks OK. a good place to buy fittings and hoses is www.dreamworksrc.com

MarkShapiro

My Feedback: (52)

Thanks, i3dm!

Chris Nicastro

My Feedback: (3)

I've designed one that is reversible, flow rate control and has LiPo low voltage cut off. It's been tested with gas, diesel and water to good effect with no problems. I'd like to produce it in small batches but the cost it high to get circuit boards made.

Air Works

Hi do you know if these pump are reversible to enable the tanks to be emptied?

Regards,
Paul

stevekott

I don't think that pump is reversible. Looks like your standard automotive fuel pump. You need to think 'transfer pump'.

Air Works

How do you empty the tanks?

i3dm

My Feedback: (51)

most of these pumps are just a motor and some kind of transmission.
i'd think it will work in reverse. maybe not as well as forward, but it should work.

stevekott

If it's got the little motor and a geared or vaned pump it will probably work fine in reverse. Some of the automotive fuel pumps have check valves in them to make them function and I don't think they can be reversed.

Zeeb

My Feedback: (41)

Well it's not as hazardous to play with Kero, diesel or Jet-A as it would be gasoline, but one of the reasons the commercial stuff is spendy is due to explosion proof switches and housings.

One other thing I've learned the hard way after starting to fly jets, is that you MUST either have a slow to medium flow rate pump or an adjustable speed pump to prevent putting too much vacuum on the tanks while defueling; they crack when subject to excessing vacuum as they weren't really designed for that.... Just a thought or two.

i3dm

My Feedback: (51)

never seen a hobby grade explosion proof item!