My wife currently has a Zappy made by Zap and loves it except for when going up a hill or in grass the front wheel loses traction. I am building her a similar design but I want to drive from the rear wheels. My question is drive motor options. If a live axle will it turn? Would a transaxle be better or dual drive motors? She like the speed of this one at about 13 MPH and the light weight design so want to keep it similar. She also like the freewheel going down hills when in a campground and running the dogs. Any thoughts or suggestions would be appreciated.
Adding freewheeling sprockets to the rear wheels would allow for even easier turning with a dual motor system because the outside wheel could freewheel when going faster than the inside wheel. 13 MPH is a very reasonable speed to achieve with a single or dual electric motor drive system. Depending on how steep the hills are that you are designing it to go up I would use two motors rated between 250-500 Watts each. A dual 250 Watt motor setup would be able to climb moderate hills with a 13 MPH top speed gear ratio, and a dual 500 Watt motor setup would be able to climb fairly steep hills with the same gearing.
I think I have located wheels and axle so will be going with a 3/4" axle. 6" wheels so overall height should be in the 12-13" range so you can gear it accordingly.
Motor I want to change up and go with the 450W item MOT-SD36450.
Throttle - I have a brand new half twist 36V throttle, three wires on it so don't need that.
Batteries would be three of - BAT-12V22A.
I just finished making a kit for your project. Please look over all of the parts in the kit and let me know if you need any changes made to it.
Couple of questions. We spoke about freewheel clutches for both sides, do you still recommend these? If I send you a nice little headlamp, key switch and horn assembly off of a Zappy 3 Pro-Flex can you add connectors so it will plug into this module as well? If you could do that I would need only one of the handlebar power switches but would need to add one of a SWT-32. I also need the following if you wish to add to your kit for ease of ordering.
I am sure there is more but would like to get these items and start fabrication around these.
We do not have 70 tooth sprockets that fit onto freewheels. The sprocket sizes we have that fit onto freewheels are 55, 65, and 80 tooth. I ran a gear ratio calculation and found that with the 65 tooth sprocket the top speed will be 17.07 MPH, and with the 80 tooth sprocket the trike will have a top speed of 13.88 MPH. Here is a screenshot of the gear ratio calculations.
The freewheel will be significantly more difficult to mount to the wheels than a plate sprocket. We have freewheels that catch in both clockwise and counterclockwise rotations so that is not a problem. However these freewheels thread onto hubs with M35X1.00 left hand and right hand threads. That is something to consider when choosing whether to use freewheels or not. Before I make a new kit with freewheels and different size sprockets could you please investigate whether you have the resources to mount the freewheels onto your rims? Also if you decide to use freewheels please let me know which size sprockets you would like to use.
That does make it a bit more challenging. Do you have any type of hub or wheel that these would thread onto? Are the clutches made of steel and if so could I weld an adapter plate to them or would this hurt internals? Have done some looking for RH and LH dies of this thread pitch and find many RH but not LH. The 80 tooth sprockets will be fine. I did ship the headlamp module we spoke about on Monday via UPS so you should be seeing that any time now.
The right hand thread freewheel will thread onto any of our rims and wheels with threaded hubs. The left hand freewheel is not very commonly used however we do have one rim for 12-1/2" tires that has a hub with reverse M34X1 threads. The rim for 12-1/2" tire that we have available with both right and left hand M35X1.00 threaded hubs looks like this.
The clutches are made entirely out of steel and should hold up to careful welding as long as they were re-oiled after they cooled down. They can be re-oiled externally without taking them apart.
Left hand M35X1.00 threads are rare so I am not surprised that a die can not be found for it. Welding the freewheels onto 35mm OD steel pipe may be the easiest way to attach them if you want to use them with steel rims.
I am sure I can chuck up something in the lathe and make a nice adapter plate for the clutches so not overly concerned, just thought you might have something available I could adapt or use to work. I will look at the price of this wheel later, might be able to destroy it for adapters cheaper than spending my labor building them.
I did insert a note in my shipment to you about possibly in your wiring harness installing in line connectors from any wires running from the handle bars so I can easily install them in the plastic body that will be used with this build just in case I need to separate the fork and handlebar section in order to travel on airlines. I also left my phone number in there so you can call and discuss in person.