My life with Python trikes Mk1 , Mk1.5 , Mk2 ?

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Hi all

Tilter #3 = 100 miles

Oh sh*t moments 0/10
Enjoyment 10/10
adventure 10/10
interesting 10/10

So it came to pass that 100 miles was reached , without drama this time :LOL:

Nothing to note with added elastomer resistance , titling seems largely unaffected , I assume because my mass and the forces still easily overcome the elastomer resistance.

I did notice something mildly interesting , it happens on all rides however now nothing is ' panic ' or ' what is happening now ' it is easier to spot and mull over.

I seem to have 2 tilt modes ?

I sometimes just tilt my shoulders , so what is called in the trade I believe ' body English ' , the base of the seat seems to stay horizontal and I tilt my upper body slightly unsure whether I did this on the non-tilter ?

Other times when I want some tilt , and sometimes all I can muster , I swivel my hips and can feel the seat base go ' off centre ' as it complies , bizarre ? where did that come from ?

When Tilt#4 is on the road I will rebuild the non-tilter , by then I may have done over 200 miles on my Tilt#3 & Tilt4 [ only about 30 to go , so 3 trips to mothers.

It will be interesting to compare the 2 mon ami ;)

Still rolling along Paul
 
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titling seems largely unaffected
You are supposed to be riding a trike, not touching women's busty-substances (cue Peter Cook & Dudley Moore Sketch). ;)
 
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Dan

You seem to have a elephantine memory for smut ;)



Getting ready for seat mounting, still using seat sub-frame on this one ...



Seat mounts copy of Mk1 python [ they worked ok , just ugly and heavy on hardware :whistle: ] you can see a 3" mark just to right of front mounting I would like that range of adjustment for those of a inside leg dimensionly challenged nature [ you know who you are ]. It can be seen the rear one will not slide forwards that far as it will hit the front elastomer.
The solution will be change the rake of those rear struts and mount it at the end of the sub-frame 3" from the left of the rear most elastomer [ so more vertical ] then I should get 3" that way as well.

Reminder #1 why I am on this path of discovery ? getting to old for low :LOL:



Seat higher by 10" at front new one 18" !
Can you see my mistake ? I like the pedals at the same height or up to 5" higher than the seat , as I bodged the front end first I got that wrong and they are about 5" below ! DOH

Reminder #2



1 Holland jaunt and 2 winters and no refurbishment for 2 years , it is VERY dirty 5" off the deck !

Paul
 
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Paul
Posting thumbnails leaves me looking like Sherlock Holmes with a spyglass in front of the monitor.
Well they ain't thumbnails at this end !

Paul
 
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All full size pics here too! :)
 
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Hi

Well I have ridden the Tilt#4 about 1/2 mile.

So twice around my locality , no brakes of course and only 226 kg of elastomers.

First off the drive there was an odd problem where when it tilted the front end stayed tilted over until I tilted in the opposite direction , traced to M12 nut's only hand tight on the pivot mount.

One brake rubbing and only stayed in first as most of the riding was around in circles on the grass.

Still behaved as expected and no drama's and no need for feet down panic's , so much better than any of the yards done so far on the Flevo Trike :whistle:

Second time off the drive much more stable , there are no front end pivot stops so the pedals can hit the floor if I am not careful.
However as the steering is not now linked to the tilting/seat so that is fine , I may leave it like this as if you put the front end down gently it stops the need for a parking brake [ although having one does prove useful on occasions].

Before any serious miles I need to paint up the seat supports and connect the brakes , add a rack and some panniers.

Paul
 
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Hi all

Tilter #3 = 112 miles

A interesting observation ..

A panic moment ....

A mechanical failure that have the potential to be BAD !

A interesting observation ..
I ride up a grass bank about 30' to get to the end of a Cul-de-sac I then ride a little bit of pavement and use someones drive ramp to get onto the road.
The ramp slopes off to the left and I traverse it at about 45' so a left turn and then a straighten up , as I go down the slope the trike is turning to the left however I am tilting to the right to remain vertical , it would not be possible to do this safely with a lean steer trike I would have to find another way down.
However IF i rode a lean steer trike would I realise this or remember it every time I confronted this type of situation , or would the trike just dump me every time ?

A panic moment ....
Now this is dumb ! I had a panic I am about to be dumped moment and I was standing still !
I parked up a ring a mate to say ' are you in for coffee ? ' expecting a yes or no answer I was sat out of the way next to the kerb with both feet clipped in and phone in hand. he wanted to talk and as I fidgeted the front end started to tip to the left , no hands on the bars I tried to unclip the left foot which hung in the clips :whistle: at this point the seat decided to join in and tilted to the left as well .. I just got my foot free and down before i exited the seat and was sat on the kerb. I was startled and caught unawares as to how fast it started to go pear shaped. However nothing but dignity was lost however worse was to come only 1/4 mile later.

A mechanical failure that have the potential to be BAD !
I set off hope and was on the pavement besides a busy road when a young girl just ' appeared ' pushing a dolls push chair straight across my bows. I stopped smartly appologised for startling her and her mother came to move off and the trike would not move , the left brake lever was very hard so I assumed the brake cable was fouling somewhere , I dragged it onto the grass to find the cable wrapped around the rear axle and the back plate free.

I disconnected the cable and rode home [ slowly ] with one brake.



So this is the right side a headless M6 bolt screwed into a hex coupler with a locking nut.



And the left side , hmm no un-threaded portion of the M6 bolt , I did search the scene to see if I could find it however it was not close by ?



There is a sharp step across the fracture , very hard to photograph



I assume in 112 miles it has fractured across the bottom of one of the screw threads ?

I was curious why the other Python using the brakes had given no trouble over a couple thousand miles , however I mounted them in a different way.



I need to repair the Tilt#3 as I have some more experiments to do with it , and improve Tilt#4 so the same does not happen again.

Relieved to be home safely Paul

ps good or bad the failsafe mode in this case was left brake fully on with a vengeance ! least in this case that helped.
 
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Wow!
Glad you escaped largely unhurt.
Having the backplate secured that way is not good (IMHO).
Now this is dumb ! I had a panic I am about to be dumped moment and I was standing still !
I parked up a ring a mate to say ' are you in for coffee ? ' expecting a yes or no answer I was sat out of the way next to the kerb with both feet clipped in and phone in hand. he wanted to talk and as I fidgeted the front end started to tip to the left , no hands on the bars I tried to unclip the left foot which hung in the clips :whistle: at this point the seat decided to join in and tilted to the left as well .. I just got my foot free and down before i exited the seat and was sat on the kerb. I was startled and caught unawares as to how fast it started to go pear shaped. However nothing but dignity was lost
Can you explain this "front-end tipping" on a python that usually wants to always stay upright because of the pivot? I say this because normally as you sit in the seat, the front-end "straightens-up" from its normally lazy Left/Right leaning pose when there is no rider on board.

Was this an elastomeric-incident? Any splits in the elastomers?
 
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Wow!
Glad you escaped largely unhurt.
Having the backplate secured that way is not good (IMHO).
Yes there are several portions of the ride that would have not been welcomed , oddly I took a different route home and missed the 24 mph under the bridge that was the cause of the last scare spooky eh ?



Only copying the way ICE did the early trikes , although they did not use a bolt.
You really need a jig to weld them accurately , which I don't have.

Can you explain this "front-end tipping" on a python that usually wants to always stay upright because of the pivot? I say this because normally as you sit in the seat, the front-end "straightens-up" from its normally lazy Left/Right leaning pose when there is no rider on board.
How long will it stay up if you are clipped in ? not moving and making a phone call ? the weight of your feet and legs are enough to unbalance the front end,

Was this an elastomeric-incident? Any splits in the elastomers?
Only in as much as they allowed the seat to tilt once the legs had begun to fall to the left , undamaged when I looked .
The tilt angle was very small , you will be amazed how little actual degrees of tilt feel huge in the physical world especially if you feel the tilt is increasing not steady.

Paul
 
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There's a lot of leverage on the headless bolts. From the stress failure picture it looks as if it was slowly weakened by normal use then polished off in one by a hard use. The "good" one is likely to be weakened also. I suggest you need to lower that leverage and get the mount as close as possible leaving the leverage at a minimum. Uping it to a M8 would be desirable too. I'd also suggest a high tensile bolt.
 
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Popshot

Yes I think it was loose in the back plate hole and the constant banging as it brakes and releases was the main culprit.

Yes we , DannyC and I , have come to the conclusion I need to add spacers and bolt them up tight , this is made extremely difficult as there is no clearance for a M6 bolt to come through from the wheel side when the wheel is already mounted.

Spookly we have also discussed taking it out to M8 , however that only makes the clearance problems worst.

Paul
 
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As discussed this morning Paul here is how I mount my drum hubs.

I use a thick piece of 10 x 50 flat bar stock and drill the hole for my QR axle-tube. I have to have my hub axle tubes accessible and underneath the 38mm square rear axle cross-beam.
A thicker plate means less chance of distortion.

I mount the backplate onto this and measure how big a piece of 12mm round bar will be required to fit in-between the face of the flat bar stock and the backplate tab with the fixing hole so that when firmly fastened the backplate is not distorted in any way. You can drill a 6mm clearance hole and put a bolt right the way through (of course). I drill and tap for M6 as my preference.

You could use bolts and drill a 12mm hole through the flat stock and weld a suitably sized bolt and use 12mm locknuts for your style of SA hub as you do not use QR axles.

This can all be put together on the bench and the final operation is to make 3 edge welds and one fillet weld to attach the plate to a squared off end of a 38mm square tube.

HTH.




 
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Oh, BTW, you will often find a degree of variability in the actual diameter of M12 bolts and indeed the actual size of the hole an M12 drill makes.
So, I would suggest you get an 11.9mm drill (they do exist) and ream the hole out to 12mm as this will be more precise.
 
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That 10x50 looks like a hell of a lot of weight.
Are we weight weenies?
Are you suggesting this lot weighs nothing in comparison? ;)

 
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Dan

Thanks , definitely food for thought.

I wonder whether it is work the trouble of getting a 11.9mm drill and reamer ? when the bolt is not an accurate M12 ?

Obviously I am looking for precision where it can't exist , then they are maybe more precise than some of my own work ;););)

Paul
 
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Are we weight weenies?
Are you suggesting this lot weighs nothing in comparison? ;)

There are places where weight can be avoided and places where it can not. The clamping set-up you point out is a complex dual axis pivot relying on the friction of the clamps for fundamental integrity. As such the clamps need a large surface area and need to be substantial to generate enough friction. I could not find a lighter system I could make that would work without completely sealing the thrust bearing in so to make it unserviceable. If you could devise a lighter system please tell me. I do not purport to have any monopoly on the best ideas.

By contrast mounting a backplate is a much simpler task with no moving parts, where a 40x20 ish box section with a pair of reinforced holes would both be stronger and much lighter than bar. Bar has many great uses in bracketry etc but is rarely the best choice for larger pieces of chassis, though I very much understand we often use what we have rather than what is best. In my case I deliberately added weighty bits by reasoned choice here as I could not conceive of a better system. I have, on other occasions, used poorer solutions because I had them already.

If we were weight weenies none of us would use trikes but making something unnecessarily heavy has no benefit and ought to be avoided where you have the choice. Swapping bar for box is simple, lighter and stronger.
 
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