Edit- updated with links to files.
Aging and an injury started to make it harder for either my partner or I to move the airplane into the hangar and we decided to look into tugs. Commercially available tugs were just a bit more money than we were up for spending, and I decided to look at making my own.
After watching Youtube videos of what other people did, I found someone who would share what major parts they used. I was concerned that If I chose a motor, gearbox, controller and wheel, it either wouldn't have enough torque or wouldn't be controllable. Having someone provide some insight into the key parts was very helpful. Also, I have gained access to a TIG machine and wanted to refresh my welding skills.
The tug is designed specifically for the rV-6A. I tried it on the RV-9A and it will work with different lugs to pick up the tow bar points. A fairly minor change. It will probably work on a -7A but I haven't looked at a -7A to know for sure.
Besides the basic requirement for it to help me move the airplane, I also wanted to minimize the space the tug took up in the hangar. The result was a unit that was more compact than most and that stores under the airplane wing.
I am open sourcing the information and will make details available to anyone building their own. Depending on how many folks ask I may just email the info to them, or I may make another "how to" video and link the files there.
The tug is quite easy to handle both while maneuvering it for hook up and while towing. It has plenty of power, and at top speed moves at a good fast walking pace. It isn't going to win any races, but that is not what it is for. In some cases, tire traction needs to be increased by applying some weight to the tug handlebar. Maybe 10-20 lbs. tops. The tug itself is fairly light- I can pick it up to my workbench, but heavy enough to get the job done.
The link to google drive folder for the parts list and drawings is there, and I am putting it here- https://drive.google.com/drive/folde...HV?usp=sharing
I had a significant number of requests for the info, and I have decided to do a tug build video in a couple of weeks.