PlanetDad said:
But don't see any hub motors for 29 inch bikes.
Perhaps the search engine you use doesn't work right.
There are a number of direct links in the search this links to, using your exact phrase above:
https://www.google.com/search?q=hub+motors+for+29+inch+bikes
If for some reason they don't come up for you, I'll copy them from the search results I see here into a new reply.
Can I just have the motor put on a diffrent wheel? Would it even work?
Sure. Just remember that the larger the wheel diameter, the faster the wheel will turn for the same conditions otherwise, and the less torque it will have.
So if you start with a motor that's meant to go 20MPH in a 20" wheel, it'll try to go 29MPH in a 29" wheel...but it'll only have 69% of the torque it would've had in the smaller wheel.
If you're interested in the differences in the performance, etc., you can go to the http://ebikes.ca/simulator page and play with various motors, cotnrollers, and batteries, to see what combination of items at what wheel sizes do different things. Might take a little while of playing with it after reading the directions, to learn how it works, but it is very useful when figuring out a system to use on a new bike.
However: Before you go much further, I highly recommend going to this thread
https://endless-sphere.com/forums/viewtopic.php?f=3&t=66302
and copying the list of questions from that first post, and then paste them and your answers here in this thread. That will let us be able to help you pick the right kit or parts to make a bike that does what you want it to do.