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corgi1

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Re: The Bent Zombie Tribrid Tadpole Trike (build phase)

That lessens the slide in the corners,lol.........I think on a further page there is an interesting 3 wh morgan about the same only less areodinamicly inclined,lol
 

2door

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Re: The Bent Zombie Tribrid Tadpole Trike (build phase)

That whole website is great. I had to pirate a few photos that I'm using for background.
Another member posted the original link, now I can't find it again. Rats!
And, it does look like a rudder. I wonder if it's controlled by pedals :)
Tom
 

BarelyAWake

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Re: The Bent Zombie Tribrid Tadpole Trike (build phase)

Well it's defo been a while this time lol - as ya'll may remember, I mentioned previously that I had hit a snag, that I had "a bit of a bump steer issue" heh

Well... TBH it was a bit more than a "bit" in fact, it was bad 'nuff to be a dealbreaker - the entire project was in jeopardy. The taddy would be extremely unstable, lurching into traffic or the ditch if any significant bumps or holes were hit. Even worse was I couldn't seem to find any easy answers despite my fondness fer research >.< Taddys aren't usually fully suspended so although I had plenty of info on the other aspects of the steering geometry, I had nuffin' on this. Cars & four wheelers etc. usually have this all worked out for ya sos there's not a lot of DIYer tuts out there, the closest would be off roaders w/their extreme modifications... but even that wasn't directly applicable... I actually had to use me own brain on this 'un blarg!

I did know that the problem was in it's steering... that was the obvious bit lol, what I couldn't figure out was what exactly had gone so wrong. Here's a coupla pics of my original setup, steering plate & tie rod routing - it looks nice enough, but it was conspiring to kill me o.o



In my haste to get stuff fabricated I'd forgotten to do any compression testing with the tie rods installed. I'd done travel tests when I was workin' on the shock mounts ofc, but once that was sorted w/o problems I pressurized the shocks and kinda forgot about it. It wasn't until I got the seat mounts done had started putting some weight on it did I notice there was a glitch - but even then w/the shocks at full pressure the travel was limited and it seemed... minor.

It wasn't minor... not even a lil bit.

Puttin' the taddy back on the bench I depressurized the shocks completely and was horrified to discover the profundity of my oversight, granted at zero pressure the effect is exaggerated far beyond any "normal" riding conditions, I'd hafta destroy both front shocks to ever have it be this bad, almost 6" of separation at the tire's farthest points - but that didn't matter, even under normal compression the effect was enough to make it extremely dangerous, even small amounts of bump steer would cause it to be "twitchy" - here's a coupla pics at it's farthest travel extremes;



...here's another showing the taddy's ground clearance with all the shocks depressurized completely, leaving me with a scant 3" of clearance (lowest point) should they all bottom out simultaneously - unlikely, but good to know anyway lol;

 
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BarelyAWake

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Re: The Bent Zombie Tribrid Tadpole Trike (build phase)

I hada suspicion that where I'd gone wrong was the angle & length of my tie rods... alla that had gone together waaay too easy to be trusted, I'm hardly an "expert" with such things but I do know that if it's that easy, ol' Murphy is takin' the opportunity to have a few lols. So, after finally finding a bit of info on the issue http://www.thedirtforum.com/bumpsteer.htm I decided to experiment with all of the angles and lengths just to see what happened, if it got better or worse *shrug* Time consuming as I hadta fabricate stuff jus' for testing... but as the whole project hung on just this one problem it didn't matter if it took time, it was an "all or nothing" scenario and there was no way in heck I was gonna call it quits b'cause of somethin' like this.

So, lookin' at it the most obvious suspect was the angles of the tie rods vs the A arms, essentially opposite they crisscross, making an "X" because the steering plate was so low, the spindles so high. Given the results it was obvious this was just plain dumb. So I made a coupla 1 & 1/8th inch drops for the spindle's control arms, lowering the outer tie rods ends to the same as the ball joint's lowest point (any lower and I'd worry about hittin' stuff w/it) - while the tie rods angle was still not the same as the A arm, it was reduced significantly & after depressurizing the shocks again I found that I'd reduced the toe out by 2" just from that mod alone!

AH! It's defo the angle that's the problem, thing is, doin' some really basic math I figured it wasn't gonna be enough to just lower the outers and raise the inners, at most that was gonna reduce it by 3-4" and I had a ghastly 6" to rid myself of... but I was makin' progress and it belatedly occured to me if it was that sensitive to angles, length was no doubt important too...

So - I flipped the steering plate over & cobbed a patch for the tie rods, giving them 3" of separation so they'd have the same pivot points as the A arms & cutting the rods back a bit & raising them so the A arms and the tie rods would be almost the same, sounds simple enough but this raised havoc with the mounting as I hadn't designed the clearance in for the plate to be upside down... or rather I'd had it upside down to begin with and was only now realizing it... whatever lol - it WORKED!!!



In it's new configuration & under max compression (shocks depressurized completely) I've now only 1/16th inch of toe out, effectively none under any riding conditions! The remaining 1/16" is doubtlessly because the tie rods are still slightly longer than the A arms, they hafta be as there's no other place for the steering plate *shrug* but hey, I'll take it! Here's some pics, the second is w/just one shock down - still no bump steer effect w00t!



Yea, I've still gotta finsh up the welds on the plate & pretty it up, make gussets for the spindle drops & weld those up too, even drill a coupla holes and lower the linkages on the handle bars 1/2" to make up for the ratio changes resulting from the plate reconfiguration, it's waaay too sensitive now - but that's simple as pie & I left plenty on those tabs for that kind of adjustment.

Forgive the rants, I can't tell ya how much this had me worried, or jus' how psyched I am now that it's solved - finally I can move on to less dire things, this problem was WAY outa my "comfort zone" lol
 
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corgi1

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Re: The Bent Zombie Tribrid Tadpole Trike (build phase)

I had faith in you, I knew you could do it
 

BarelyAWake

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Re: The Bent Zombie Tribrid Tadpole Trike (build phase)

A very informative mistake! Glad you got it sorted out, but prolly not as glad as you are! :D
Agreed Aleman :p While I'm not particularly fond of painting myself the fool - there isn't a lot of info on this particular aspect of steering geometry (that I could find anyway) & as I hope someone else may be inspired to build somethin' similar - I hope they can benefit from my mistakes, silly tho they may be lol

In retrospect it's obvious enough, so obvious in fact that I wonder if that's why the info isn't so available... *shrug* Whatever the case - I've learned something new (to me anyway) and that's awesome, the only thing that matters I figure.

I had faith in you, I knew you could do it
Thanks for the vote of confidence corgi :D Ofc now I'm wondering what you know about me that I don't... o_O Awgawd - never mind, don't answer that lol

Yea, I figured I'd muddle my way through it sooner or later TBH, it's just that it was so unexpected and so bad of a problem it caught me off guard a bit, it's always bad news when a pessimist finds out he's actually been an optimist laff
 

fasteddy

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Re: The Bent Zombie Tribrid Tadpole Trike (build phase)

BarelyAwake, anyone who could pull a vehicle like that together without blue prints and plans is going to figure a way out of the problem no matter how bad it is.

I can only imagine your first thoughts when you saw the problem and what a heart stopper it was.

Thanks to your information I'm making sure the tri-cars have the right angles built in. We'll know this summer if I did it right. 0.0

Steve.
 

Tohri

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Re: The Bent Zombie Tribrid Tadpole Trike (build phase)

Hey mr. Barely, I just figured you might want a look see at something I found on one of my mad science hunts.
Boostcap - Capacitors-The Electronic Goldmine

Maybe with their (Dangerously) Fast charge/discharge times and Equivalent Series Resistance they'd be a good balance for the batteries and ICE. Though with the kinda juice these suckers store, you could probably ditch the batteries.
 

BarelyAWake

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Re: The Bent Zombie Tribrid Tadpole Trike (build phase)

lol fasteddy, who said I don't use "blueprints" or "plans"? I scribble lil diagrams & doodles all o'er the place, even my desk at work is covered in post-its, half formulated thoughts that haven't gone anywhere yet, there's a snowdrift of scrap paper with unintelligible sharpie scrawls behind the taddy, tastefully hidden by that scrap of plywood heh

I laid 'em all out one day and took a pic, but as they only covered 1/2 the 4x8' workbench & as I'm only 1/2 done - I figured I'd wait till it's rideable & then take another pic... ofc those don't even include the endless last second notations & marks on my favorite notepad, the other hand lol

Ofc... they're all wrong in one way or another, some critical detail overlooked or jus' a "ballpark" guess. Being a bit of a 'puter geek I thought about doin' some CAD renderings... but honestly? I've found that for me - it'd take just as long to render as it would to build the silly thing & all I'd have to show for it are some pretty pics that may or may not be accurate in any case. *shrug* Might as well break out the scrap steel, power tools & set some stuff of fire, jus' ta see where it gets me :D


Tohri - thanks for the link! There' a ton of groovy stuff on that site & now you've got me tryin' to figure out how to use some of it... for no other reason than it's neat o_O

But.. I gotta say I can't quite figure how I'd use those capacitors given they're for "applications requiring enormous instantaneous charge and discharge power" - while the concept is intriguing (picturing a sorta NOS for ebikes), I can't help but picture detonated spokes and an incinerated hub drive... it'd let all the "magic smoke" out in a hurry I think...

Granted, I'm an En00b unfamiliar w/advanced electric drives - do you have any links/reference material on how they could be used?
 

BarelyAWake

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Re: The Bent Zombie Tribrid Tadpole Trike (build phase)

...aaand we're "back on track" FTW, spent the weekend cobbin' together the drop spindle thingiez whatsits (obv that is highly technical professional jargon ofc) - I was a bit concerned about lateral strength so I made some relatively monstrous gussets outa 1/4" thick aluminum plate, long enough that they join the tie rod plate to the spindle box as well by crossing over the seam between the two... I don't think they're going to be a problem lol



Yea, they're not the prettiest w/the edges still sharp and unbrushed, but I figure I'll shine everything up when I'm done, all the chassis & other bits need to be sandblasted & repainted too so that'd be the time to worry about such I s'pose...
 

BarelyAWake

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Re: The Bent Zombie Tribrid Tadpole Trike (build phase)

...as well as finalizing the steering plate, which TBH was a lot trickier & time consuming as there's so little room - sometimes shaving off as little as 1/32" at a time & reassembling to see, I worked "worse case" with all of the assorted angles at their unimaginable extremes, the tie rods far beyond their normal travel ranges.

Unfortunately I was forced to make some "custom" length bolts, something I try to avoid jus' in case I've a "roadside repair" I need to deal with, but it is what it is & at least I didn't hafta cut the heads off & weld 'em in as studs *shrug* (they're all high quality marine grade Yamaha engine fasteners BTW, YAY for recycling lol). When it was all over w/the steering control arms dropped almost an inch (at the handlebars to reduce steering sensitivity) It all came out snug, but with a lil room to spare... making a nice & tidy setup I'm actually quite pleased with;



Best yet is ofc the fact that it all works & works properly this time lol - the only steering related issue I need to deal with now is the actual handlebars, they're only tack welded... and I'm not quite sure I like them. While they're positioned correctly, there's a lil too much bend & angle action goin' on & they're roughly 2" too short...

Still, they're defo good enough for now lol, I've other stuff to attend to while I keep an eye out for another pair of handlebars to chop up heh
 
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fasteddy

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Re: The Bent Zombie Tribrid Tadpole Trike (build phase)

Barely, if there isn't sparks and flames, it's just another job.

I can under stand the pile of notes to ones self with the notations that you have to decipher when you get back to it a week later. Just trying to make the spindles and holders has produced a profound pile of papers and a longer list of saved items on the favorites list.

Years ago when I made very period correct, early antique furniture. I would once in a while get someone who came in with blue prints of what they wanted. That was a WTF moment.
I used to get out a sheet of news print, slap it down with a great sigh and pencil in hand proceed to ask then just what size, ect, they wanted.
That scared them as thier eyes danced back and forth between the blue prints and the blank sheet of paper.

Truth is I can read blue prints but dislike them so a simple drawing on the back of an envelope works best.

Steve.
 

BarelyAWake

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Re: The Bent Zombie Tribrid Tadpole Trike (build phase)

Ahh fasteddy, the endless feud betwixt engineers & fabricators... funny how those that build will draw, but those that draw rarely build ;)

Where do i get one of those?
One o'whats Tmoney? The taddy itself? If so - sorry man, that's so "some assembly required" I unno where to begin lol... literally sometimes :p

If yer after a component, DIYer plans or w/e I can prolly help, there's links fer jus' about everything I've used scattered throughout the thread...
 

Tohri

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Re: The Bent Zombie Tribrid Tadpole Trike (build phase)

B.A. : Those ultracaps could act as a 'buffer' between your batteries and motor. Yes, they're great for instantaenious power, up into the hundreds of amps. But put in parallel with a battery, it increases your energy storage slightly, but will soak up regenerative braking energy like a sponge.

But yes, kind of like NOS for electric bikes. XD
 

BarelyAWake

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Re: The Bent Zombie Tribrid Tadpole Trike (build phase)

Intriguing... TBH at the moment I'm a touch preoccupied w/just trying to get all the pieces ta fit... and as the electric hub & batteries are themselves are only for supplementary performance (decreasing acceleration time/fuel consumption) at least theoretically anyway - I'm not entirely sure I'm ready to jump into modding that system quite yet... The LiFePO4 batteries themselves were actually far beyond what I expected to do w/this build, for now anyway lol (isn't that how it always goes tho?) :p

Still, it's got fascinating potential and I'll defo keep it in mind - if ya happen across any examples in yer wanderings, link them if ya have a mo *shrug* Who knows? This thing is already kinda "over the top" I s'pose, so what's a lil more crazy? rotfl
 

BarelyAWake

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Re: The Bent Zombie Tribrid Tadpole Trike (build phase)

Well, I've hit another snag - but a lil 'un this time lol, it's simple enough if a touch awkward...

I've run outa materials o_O

Well... more precisely, needful parts. I had (obviously) gotten alla major bits, the expensive & critical components that I needed for the overall project - hard to build sumfin' if ya don't know what you're building it with or what size it may be & I also wanted to get the pricey stuff purchased first - that way I knew that no matter what it'd be a simple matter of time, regardless how tattered & tired the wallet may be :p

So now it's just a matter of lil things, a 13t freewheel sprocket for the pedal chain, the ICE's wiring harness & CDI, cables, twist shifters, a left handed thumb throttle for the ICE (that 'un is proving tricky) and... well... a bunch of other doodads I'm sure I'm forgetting.

The one that's hangin' me up at the moment is the silliest thing in the world - I haven't enough multispeed chain to even test it's routing properly lol, I've two lengths & I need four just for the pedal drive - I'll need a fifth for the jackshaft to cassette... or at least a 1/2 length for that one, which is good 'cause for that I'm gonna need quality as the Lifan is goin' through it.

So as the battery tray mounts are the only other "major" thing I've got goin' on ATM & I gotta make sure those & the chain routing don't end up arguing, I've cobbed together some test idlers - jus' bits of aluminum bar drilled & tapped to take the cogs from derailleurs (those I've a bunch of heh), I've been playing around clamping them in place ta see what happens. Once I stumble on somethin' I like, I'll fab up something a bit more permanent.

First pic is jus' the testing bits, the second has the undercarriage correct & while I'd like the gentler routing, it's no surprise that's in the way of the battery mounts-to-be & I'll prolly hafta use the harder reroute in the last pic;



So it's a'shopping I must go, time for more shiny toys & treats and waiting for the blasted brown truck blarg... tho I s'pose I could troop on o'er to wallyworld and get some multispeed chain so I can figure out the tensioner & whatnot...

Yep, not going to be able to wait heh - much as I can't stand the place, wallyworld it is as soon as I get off work *shrug*
 

BarelyAWake

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Re: The Bent Zombie Tribrid Tadpole Trike (build phase)

Well, after much fiddlin' & finaglin' & fussin' about I've the chain routing sorted... It's not what I'd consider ideal as every redirect adds friction, robbing a bit from pedal power and odd as it may sound, I do care about that lol

Still, not much choice really, there's a lot of stuff in the way - A arms, steering linkages, exhaust & ofc the pesky four stroke engine itself, not to mention the much talked about but still not built yet battery tray mounts *sigh* (don't mind me, they're the last PITA bits heh).

I spent some quality time huntin' the interwebs checkin' out other ppls madness, lookin' at various factory taddys & other recumbents to see what they had done and was greatly reassured to see mine's not too bad, two wheeled recumbents in particular can get a lil crazy it seems. Some less expensive ones rely on chain tubes alone to direct the chain, even on the power side - and that's not well liked by the 'bent riders at all, for obvious reasons. Many have far larger idlers to reduce drag but would you believe they want about a hundred dollars for the silly things? Sure, they're pretty cool lookin' - but... seriously? o_O

Good thing they wouldn't fit my build anyway heh

Nevertheless, I do need real idlers, a chain tube for the return side & a freewheel sprocket. I need a real tensioner too, that one is just a frankensteined derailleur clamped in place to test location & length (yea, it's too short). While I'll prolly make that - I found these pretty sweet sealed bearing cogs at my local bike shop... sorta, they're outa stock ATM but w/e, I've part numbers FTW (better restock Zack, else it's Amazon I will go) o.o
Bikeman: e.13 Idler Pulley for '06 and Newer Guides

I also sorted out the four stroke/jackshaft chain & sprocket. I was a bit concerned I would need a tensioner/guide for that one too - but as it turns out the pivot point for the suspended stays is so close to the jackshaft (through the old bottom bracket) that the travel is marginal - the chain tightens as the suspension compresses and it's unloaded completely in the pic. I measured & put the chain on w/the shock bottomed out and as there's only a little slack unloaded I think I can manage w/o anything at all! At this point I just need to cut the shaft to length & that's done... 'cept I've gotta pull it all back apart to paint the stays ofc... grease everything & cut keys... oh right, that freewheel for the pedal side...

Ah well, ya kno what I mean heh