Homemade Electric Powered Self Propelled Mooney Towbar

[MinneMooney]

Here is a list of materials I used to fabricate a powered towbar to tow my Mooney. I have attached pictures and a couple of drawings too. Hopefully, that will be enough to build your own, if interested. I spent about $150 to make mine.

Materials List

eBay

1 – Jazzy Wheelchair Gearbox Motor

1 – Wheelchair Wheel & Tire 3.00-4 (10” dia)

Amazon

2 – 12v 9Ah Rechargeable Batteries

1 – 10-55v 60A Reversible DC Motor Speed Controller

1 – 60A Inline fuse holder

1 – 6”x3-1/2”x2-1/2” IP65 Junction Box

1 – 3-1/2”x2-1/2”x1-1/2” IP65 Junction Box

1 – Pushbutton Momentary Starter Switch

Metal

Towbar

1 – 4’L -1”x1”x1/8”  steel square tube

2 – 3”x4”x1/8” steel plate (drill 1” hole 1” from the top through both)

2 – 4-3/4”x1-1/2”x1/4” steel plate

1 – 6”L - 2”x3/16” angle steel

1 – 12”L – ¾” black sch.40 steel pipe

Battery Support

2 – 6”L – 1” x1/8” angle steel

2 – 2-3/4”L – 1” x1/8” angle steel

1 – 8”x1-1/2”x1/8” steel strap

Handle

1 – 12”L – ½” black sch.40 steel pipe

2 – 4”L – 1” x1/8” angle steel

This is drawn to scale. each square = 1".

 

[MinneMooney]

Feel free to ask me questions. It weighs about 45#. You do have to get down on your knees to attach it to the nosegear. However once it's there, I leave it in place in the hangar. The momentary pushbutton is wired into the speed control so that everything stops unless you are pushing that button. Very easy to stop that way. 

I've used it for about a year so far and it's working great. I even pushed the plane back into my hangar over a layer of snow and ice the other day without slippage. It just took a bit higher power setting than normal. In the summer I rarely set it above 50%.

[J Bird]

What did you use to switch between Forward and Reverse? 

[MinneMooney]

I think this is the control I bought. It comes with with a rocker switch to switch forward/reverse, a rotary on/off speed control, a digital display and it had contacts on it for me to add the momentary push button to switch a solid state relay on the power supply board. 
That way, all that power for the motor does not run through the switch. So,  I could use a $5 5 amp rated switch and not a 60amp $$$ switch!
 

[J Bird]

Why did you go with 2 batteries? I know there cheap but wouldn't 1 be enough or do you think the power draw is a bit much from the motor?

[MinneMooney]

The batteries are wired in series. The motor is 24volt.

I did try it at 12 volts just to see what it could do. It was really slow moving the plane and it had very little power. The difference @24volts is dramatic.

[MinneMooney]

Also I was able to buy 2 batteries for about $30. Can’t beat it for the price. 

[J Bird]

Didn't realize the motor was 24V. 

[MinneMooney]

The key to this was that I was able to buy a drive motor/gearbox and a tire for $40 on eBay. I used to see them listed fairly often a year ago. Not so much lately.

[J Bird]

After looking at some pics, the gearbox is attached to the wheel without the wheelhub? The wheelhub is 5 bolts and the wheel pattern is 4 holes. 

[MinneMooney]

I modified the wheel I found by drilling it out to 1” to fit the shaft. I then cut a key way into the wheel using a file, which was not that hard given that the wheel is aluminum. 

[MinneMooney]

I have seen some drive units with wheels for sale in the past. That would have kept things simpler.

[MinneMooney]

I just found that searching for “Jazzy motor” on eBay still brings up several sources for $32.50 with shipping. You would still need to adapt a wheel to fit unless you get one of the 14” wheels with the 5 bolt hub. Then my concern would be that it would travel 40% faster and have a lot less power at the same rpm. I would estimate my setup moves the plane (on level ground) about 5 mph at 100% on the speed control. That’s fast unless you’re traveling in a wide open area. I’m usually down around 40% when I’m pushing into the hangar and slowly decrease to 15-20% until it hit my wheel chock stop.

[carusoam]

Nice work Kim!

Thanks for sharing all the details.

Go MS!

Best regards,

-a-

[MinneMooney]

Someone just sent me a message asking about several items on Amazon working for this project. Somehow the message has disappeared. Please resend.

[DonMuncy]

This is good. We now have a couple of tugs available to build (and/or buy in my case). MinniMooney's works with the drive wheel against the nose tire, and mine uses traction between the drive wheel and the ground.

[Tx_Aggie]

11 hours ago, DonMuncy said:

This is good. We now have a couple of tugs available to build (and/or buy in my case). MinniMooney's works with the drive wheel against the nose tire, and mine uses traction between the drive wheel and the ground.

Highly recommend the Muncy tug!

 

Don - the one you made me in November continues to work very well! Thanks for building it for me and it was nice meeting you!

[DonMuncy]

10 hours ago, Tx_Aggie said:

Highly recommend the Muncy tug!

 

Don - the one you made me in November continues to work very well! Thanks for building it for me and it was nice meeting you!

Glad it is working well. Let me know if you have any problems. It was good to meet you too.

[afward]

@DonMuncy I'll have to second @Tx_Aggie's comment...  I bought mine from @Salvo last August and have been quite happy with it.