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warren
human power expert

USA
6090 Posts

Posted - 11/08/2017 :  15:16:10  Show Profile  Visit warren's Homepage  Reply with Quote
Yes that would be a good change John, but that's part of my donor bike. Do I really want to rebuild the rear end of the trike. Umm...

Edited by - warren on 11/08/2017 15:20:39
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warren
human power expert

USA
6090 Posts

Posted - 11/11/2017 :  10:03:55  Show Profile  Visit warren's Homepage  Reply with Quote
It took 5 hours to cut, mitre, jig, tweak and braze this joint. And it's off. How far off? Looks like the BB will be at 10.5" now. Hmm. 6" crank length plus 7.5" of shoe = 13.5" to the ground with foot hanging straight down at the bottom of the pedal stroke.



Apparently my plastic angle measuring tool is not good for low angles.

Fortunately your foot doesn't normally hang straight down at the bottom of your pedal stroke. I measured on my bike and it looks like I need about 10" of ground clearance while pedaling normally. Hmm. I'll try it and have to tweak it a bit if it's not enough clearance.

Edited by - warren on 11/11/2017 10:04:53
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alevand
human power expert

USA
2910 Posts

Posted - 11/11/2017 :  15:57:48  Show Profile  Visit alevand's Homepage  Reply with Quote
quote:
Originally posted by warren

It took 5 hours to cut, mitre, jig, tweak and braze this joint. And it's off. How far off? Looks like the BB will be at 10.5" now. Hmm. 6" crank length plus 7.5" of shoe = 13.5" to the ground with foot hanging straight down at the bottom of the pedal stroke.


Hi Warren,
Ha, I know the feeling all to well. Maybe you can grind the heals off your shoes, or maybe the trike will do this automatically for you. Yes, foot is at about 45 degrees at BDC, so that would about be 3.5 inches clearance heal to road.



...Hopefully the spindles will turn out better with the fixture. Are planning any camber?

C:
Tony Levand

Edited by - alevand on 11/12/2017 07:36:07
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Jerry
recumbent guru

USA
967 Posts

Posted - 11/12/2017 :  10:25:13  Show Profile  Reply with Quote
Ha ha, I could lower the BB 3 more inches and still have heel clearance. I know the feeling Warren, been there, done that, way more than I want to admit! Looks like it will be a very fast trike though.
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warren
human power expert

USA
6090 Posts

Posted - 11/12/2017 :  14:57:24  Show Profile  Visit warren's Homepage  Reply with Quote
The kingpin parts are cut and ready to braze. And I actually cut the angles right. Amazing.

No wheel camber, Tony.

Edited by - warren on 11/12/2017 15:42:40
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Speedbiker
human power expert

USA
3744 Posts

Posted - 11/13/2017 :  00:07:42  Show Profile  Reply with Quote
Warren, run the boom through your tube roller!

Camber = slower.
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alevand
human power expert

USA
2910 Posts

Posted - 11/13/2017 :  06:04:37  Show Profile  Visit alevand's Homepage  Reply with Quote
Are you using the boom off the donor bike? Its too short for the bender. I adjust frames by slicing the tube part way, near the joint, with a .030 cutting blade in the hand grinder, applying force to close it, cut again to get to close most of the way and weld it up. How hard it would be to redo the joint?

C:
Tony Levand

Edited by - alevand on 11/13/2017 06:05:18
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warren
human power expert

USA
6090 Posts

Posted - 11/13/2017 :  08:25:54  Show Profile  Visit warren's Homepage  Reply with Quote
To save weight I'm going to make a CF tube for the boom that will bridge the gap between the cruciform area and the BB area. Otherwise I have to use the super heavy .049 wall 2" tubing. I can put a slight mitre in the CF tube. The CF tube will clamp over the 2" frame tubing so the boom will be removable. That way it will fit in my CRV.

A trike like this built from a bent tube would be very cool. I can bend the 1.5" OD tubing in the roller bender. How does Ben at Trisled get away with using 1.5" OD tubing to build his trikes? Are they flexy or does he just use thick heavy wall tubing?
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alevand
human power expert

USA
2910 Posts

Posted - 11/13/2017 :  10:32:50  Show Profile  Visit alevand's Homepage  Reply with Quote
Must be flexy if the trisled only weight 14 kG.
http://trisled.com.au/hpv/gizmo/" target="_blank"> br / http://trisled.com.au/hpv/gizmo/

C:
Tony Levand
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warren
human power expert

USA
6090 Posts

Posted - 11/13/2017 :  21:33:12  Show Profile  Visit warren's Homepage  Reply with Quote
Brazed up the kingpins. I don't have a lathe so I had to fake it with concentric tubes. The holes in the sides of the tubes are to braze the axle tubes together. I was able to create the proper angle hole in the steerer tube with a 3/4" holesaw. Aaaand I'm out of acetylene.

Low tech construction pics:







The next trick is to make the seats for the headset bearings.

More here: http://www.recumbents.com/wisil/trike/default.htm


Edited by - warren on 11/14/2017 08:30:26
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warren
human power expert

USA
6090 Posts

Posted - 11/16/2017 :  10:29:06  Show Profile  Visit warren's Homepage  Reply with Quote
More work on the kingpin assemblies - drilled out the axle hole to match the axle diameter, pressed the bearing races onto one of the head tubes, ordered 1-1/4x.058 tubing for use as bearing seats, found some sheet metal to use as shim between lower headset bearing race and the steerer tube. Now I have a complete assembly that I can use to make measurements to add the cruciform tubes!

Did the 1X cruciform drawing. Cruciform tubes will each be about 1ft long. These will be more tubing cuts that need to be right! The joint where the cruciform tube attaches to the head tube has to be angled in two dimensions, both kingpin inclination and caster. Fun (Not!) I think I'm going to cut the main tube at the point where the cruciform attaches to fix the boom angle. This will also allow me to attach the cruciform tubes together inside the main tube. Should be stronger and allow for some minor tweaking.

Edited by - warren on 11/17/2017 12:15:23
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Jackrabbit Jimmy
recumbent enthusiast

Canada
292 Posts

Posted - 11/18/2017 :  05:33:15  Show Profile  Reply with Quote
Warren, I see you use the same Newfie CAD system that I use.

quote:
Originally posted by warren

It took 5 hours to cut, mitre, jig, tweak and braze this joint. And it's off. How far off? Looks like the BB will be at 10.5" now. Hmm. 6" crank length plus 7.5" of shoe = 13.5" to the ground with foot hanging straight down at the bottom of the pedal stroke.



Apparently my plastic angle measuring tool is not good for low angles.

Fortunately your foot doesn't normally hang straight down at the bottom of your pedal stroke. I measured on my bike and it looks like I need about 10" of ground clearance while pedaling normally. Hmm. I'll try it and have to tweak it a bit if it's not enough clearance.



Jackrabbit Jimmy
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Speedbiker
human power expert

USA
3744 Posts

Posted - 11/18/2017 :  06:26:38  Show Profile  Reply with Quote
Now I remember why I never built at trike( except a tilter nobody ever saw).
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purplepeopledesign
recumbent guru

Canada
681 Posts

Posted - 11/18/2017 :  16:23:00  Show Profile  Reply with Quote
You built a tilter?

:)ensen.

Those who claim to be making history are often the same ones repeating it.

Video of my trike
http://www.youtube.com/watch?v=MdSLRD_2vzc
Photos of my trike
http://www.flickr.com/photos/purplepeople/
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