Trike hinge for steering arms

Continuing the front-suspension project of a tadpole recumbent trike, here are recent posts:

• Motrike 320 rear shock mounted with ordinary bolts — June 16, 2024
• Trike Mark-3 swing-arms constructed — June 14, 2024
• Trike 320 frame rear fork large gap — June 13, 2024
• Recumbent trike front suspension Mark-3 — June 01, 2024

Progress is slow, but things are happening. The most recent task has been to figure out a way to mount the steering arms. The TrikExplor 320 assembly manual has this photo, showing that the arms-hinge is bolted on the bottom of part of the cross-beam:

However, that cross-beam and welded-on extra pipework, is no longer there. So I had to manufacture something on which the arm-hinge can attach.

The arm-hinge, which is the pipework in black above, has bearings, so I had to make up something. Here are pictures. Firstly, aluminium tube 30mm OD, with dowel inside and 10mm hole in the middle:

Inserted into the arm-hinge:

A special flange is required on the underside of the bearing, that will take the weight. These are a standard thing in bicycles and if you have second-hand bikes you could probably get one off the bike. I bought one from here, 30mm ID, open-type

https://www.aliexpress.com/item/1005004651506052.html

Another flange is required on top, for weather protection. The trike already had one, that I had removed. It has rubber rings inside and out:

...however, it is for a tube slightly less than 30mm, only very slightly, maybe about 29.5mm. So I filed it to fit the 30mm tube, but then cannot use the inner o-ring. Will use silicone sealant in the final assembly. Probably could have bought that as well, with the exact required ID.

Next, constructed an assembly that will bolt onto the trike frame. 40x40x40mm square steel, 12mm hole on top, 10mm on the bottom:

Got the m12 30mm bolt from here:

https://www.aliexpress.com/item/1005003279616641.html

The m12 nut, with serrations underneath:

https://www.aliexpress.com/item/1005006974699501.html

The washer shown in the photo is interesting; it has serrations on both sides:

https://www.aliexpress.com/item/1005006121408441.html

...bought them to experiment with.

Mounted on the trike frame, upside-down view:

Finally, the arms-hinge is mounted:

...looks like an improvised construction! The bolt is too long, hence the washers; but that can be fixed.

Next up, intend to put together the linkage from the steering arms to the wheels. I had previously posted about a linkage design that is optimised for the vertical movement of the suspension; however, to get going, thinking of a simpler design.

The optimised design is complicated; the simpler design I can assemble very quickly. I want to get this trike to the stage where I can ride it! Refinements can come later. For the simpler steering linkage, I will need to do some modeling in SolveSpace first -- probably tonight or tomorrow.    

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