Timber Leaning Trike by stevenurseau

Last crawled date: 2 years, 11 months ago

Timber leaning trike. READ ME FIRST!
This trike is one I built after my industrial design masters at Monash University. Although I had built similar wooden trikes in my masters, I felt they weren’t quite finished. In particular the tailbox needed fixing. A competition and exhibition came up and I decided to finish off the design to show it in Dangerous Designs and Fringe Furniture. A few pics and a link to a video are here. https://modularbikes.blogspot.com/2017/06/dangerous-designs-entry.html
As shown the trike is quick to get on and off and start. However its impossible to turn hard and pedal at the same time. It is a recumbent simple leaning trike which combines good aerodynamics with the ability to carry loads. In my masters degree (here is a link to my master’s writeup https://bridges.monash.edu/articles/thesis/A_Simple_Leaning_Trike/5373910 ) the trikes I made are called “Nurse Leaning Trike” or NLT for short. I kept up that naming for this trike, so drawings have “NLT8” in their name, short for Nurse leaning trike 8.
The trike depends on conventional bike geometry for trail, and the design is laid out so that frame angle to vertical equals head tube angle to horizontal equals approx. 70 degrees. The frame angle is influenced by the wheel and fork size, and I have a standard 26” front wheel and 16” 349 rim rear wheels. Fork layout is similar to the one described in my aluminium trike but I used new 26” forks which did not have the extra threaded length cropped. Refer also to the aluminium trike for the setup and parts needed for the rear wheels – the difference is that a diameter 40 steel threaded bottom bracket shell is brazed into one of the bottom bracket supports and conventional bottom bracket cartridges are used. (forks.pdf in https://www.thingiverse.com/thing:4201871/files )
The cut profile includes a timber steerer with goes with stem. But neither are necessary, the steerer from the aluminium trike can be used, (fst.pdf in https://www.thingiverse.com/thing:4201871/files )
Similarly, the frame can be a plank of wood. It will be heavy but enough to get the look and feel of the trike.
Drawings and other files provided are:
All_Wood_trike.dwg : A drawing including some working sketches which may help in assembly.
NLT8-1, NLT8-2 in dwg form: These are the CNC routing profiles for the plywood sheet used in the trike. They are complete versions. To make cut profiles, non-graphical information should be stripped away and all polylines / joined lines preserved in that form. Note that parts are clumped or partially merged together. This is to save space and avoids having small parts flicked away by rotating cutters. The material is specified as hoop pine ply but I have found birch ply to be just as good.
NLT8-3 Laser cutting.dwg: Contains laser-cutting profiles for steerer reinforcement, fork dropouts and bearing bracket plates.
NLT8-4 Stem.dwg and pdf. Files for making a stem for a wooden steerer. Its not required, see note above.
This plan has been provided for free and my idea is to “put it up there” even if it’s not finished. At a later stage I might put up some extra files up like an assembly drawing for the bottom bracket areas. But for now you will have to make do with descriptions in blog files and common sense. All the blog files are linked, you shouldn’t have too much trouble navigating. Start off from here:https://modularbikes.blogspot.com/2017/04/timber-leaning-trike-part-1.html
Stephen Nurse May 2021