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

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Yes, but your will be so much better, I am sure. :)
 
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Tilt#2 = 72 miles - retired - dangerous
Tilt#3 = 272 miles - [semi] retired - proved tilting concept
Tilt#4 = 81 miles

No ride Monday as it was that dark I needed a front light and I had a parcel to drop off so needed a second pannier neither of which Tilt#4 had so I was on the 2 wheeler , made a nice change.
Monday added a front light and second pannier.
Wednesday no ride so today is exactly 1 week since I road Tilt#4 , I was a little apprehensive , however echoing something a German guy posted on their ' Learning to ride a Flevo thread ' if you need to ride it you just get on and do it and all's well ?
I have been wrestling with a problem of the relationship between the tilt pivot and the height of the C of G , I have sent DannyC several drawings non of which showed me anything meaning full , I do think though I have cracked it with drawing 4 ? Whilst musing over this and how to present it as a drawing I had little time for the foibles of Tilt#4 , being late also added some pressure to get the toes down and give it some welly.
Nice ride and nothing untoward happened ? has the inner voice become silent ?



So the drawing is of the back of the trike with it traveling in a straight line.
The fixed elements are :-
Ground
Axle height
Vertical centre line
vertical dotted line to left of centre line showing a hypothetical tilt angle.

Up the centre line are pivots T1 & T2 , these roughly correspond to Tilt#3 and Tilt#4 pivot points [ in respect to the axle ]
3 C of G points 1CG , 2CG & 3CG
I have drawn 3 lines from the projected C of G points [ where they meet dotted line ] through the pivot for T1 to the ground plane A1 , B1 & C1
I have drawn 3 lines from the projected C of G points [ where they meet dotted line ] through the pivot for T2 to the ground plane A2 , B2 & C2

So the points A1, B1 & C1 and A2 , B2 & C2 are the amount of ' tilt correction available for the chosen points and a fixed amount of tilt applied by the rider ?

So I drew an extra line X to X using T1 and a C 0f G one square above it , as can be seen nearly as good as A2?

Conclusions ?
The higher the pivot the greater the amount of tilt correction available ?
The closer the C of G to the pivot the greater the amount of tilt correction available ?

Having difficulty getting my head around this , of course it could all be hokum and my drawing/assumptions are fatally flawed ?

Paul
 
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Ok been getting some garage time ....



Tilt#4 resting in the garage , however what do you think the pile is lurking behind it ?



Sadly that is Tilt#3 , going to be reborn as Tilt#5 ! watch this space :whistle:



First up the rear will be made the same width as Tilt#4 so down from 30" to 24" , means cutting it into 3 and chopping 2.5" out of each side and welding back together.



So 12 plug weld holes drilled and about to be welded then the square tubing parts joined back together.



M12 rod through axle bolt holes and then clamped to the worktop off cut and a piece of 1.25" tubing , hope it is enough to keep it lined up whilst welding ?

I have also cut 12" off the end of the main keel and cut off the hateful [ and ineffectual ] axle/keel clamp as I now know the length I want it to be.

It has been said I am making a lot of work for myself keep cutting up the same trikes and making the next version ? surely it would be easier to start with new steel and built from that ?

Well so far I have built:-
Mk1 non tilting Python
Mk2 non tilting rear end for above
Mk2 new front end
Tilt#1 rear mainly new parts , front Mk2
Tilt#2 from Tilt#1
Tilt#3 conversion of non tilting Mk1
Tilt#4 reconfigure Tilt#2
Tilt#5 reconfigure Tilt#3

So despite having built 7 trikes I only have :-
Front ends - Mk1 and Mk2
Rear ends - Mk1 and Mk2 and Tilt#1
So I still don't have 3 complete trikes no bad going in my book ?

Paul
 
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Are you sure there's enough clamps on that? There might be space for more if you really try hard. :)
 
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Are you sure there's enough clamps on that? There might be space for more if you really try hard. :)
Aah I do need to get in with the metal glue stick ?

and in my defense I am trying to align 3 pieces.

Paul
 
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So I still don't have 3 complete trikes no bad going in my book ?
There's a lot of people on here with part-completed projects I think. Me included.
I've bailed on at least 2 tilter attempts. The 24" Python might end up the same way. :(
 
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stormbird said:
So I still don't have 3 complete trikes no bad going in my book ?

There's a lot of people on here with part-completed projects I think. Me included.
I've bailed on at least 2 tilter attempts. The 24" Python might end up the same way. :(
I think you have the wrong end of this stick ?

I ONLY have 2 ridable trikes and 1 extra rear end NOT 7 trikes taking up space ?

Paul
 
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Tilt#2 = 72 miles - retired - dangerous
Tilt#3 = 272 miles - [semi] retired - proved tilting concept
Tilt#4 = 93 miles

Near 100 miles on Tilt#4 , still nothing bad has happened , couple of have to be ' careful ' moments usually doing some think questionable at low speeds like crossing a drive ramp at 45' etc.

So Tilt#5 has started , got the rear end back together and welded to the main boom.

However gas is getting short - gauge pointer on stop , sadly still 3 small welds to do , i don't want to try it now and crack any of the existing welds.



As you can see same track as Tilt#4



It is only mildly accurate i.e it is about 1/2" [ 12mm ] bow legged and about 1/4" [ 3mm ] pigeon-toed , I can live with that !



These don't help very hard to jig up as heavy and has brackets stuck out at odd angles at the end and the vertical joining piece , adding to the problem is the fact M12 rodding is NOT a tight fit in M12 precision tubing [ neither are the m12 bolt ' axles ' for that matter !

all for now Paul
 
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Tilt#2 = 72 miles - retired - dangerous
Tilt#3 = 272 miles - [semi] retired - proved tilting concept
Tilt#4 = 93 miles

Near 100 miles on Tilt#4 , still nothing bad has happened , couple of have to be ' careful ' moments usually doing some think questionable at low speeds like crossing a drive ramp at 45' etc.

So Tilt#5 has started , got the rear end back together and welded to the main boom.

However gas is getting short - gauge pointer on stop , sadly still 3 small welds to do , i don't want to try it now and crack any of the existing welds.



As you can see same track as Tilt#4



It is only mildly accurate i.e it is about 1/2" [ 12mm ] bow legged and about 1/4" [ 3mm ] pigeon-toed , I can live with that !



These don't help very hard to jig up as heavy and has brackets stuck out at odd angles at the end and the vertical joining piece , adding to the problem is the fact M12 rodding is NOT a tight fit in M12 precision tubing [ neither are the m12 bolt ' axles ' for that matter !

all for now Paul
Looking good Paul :)
Will this back-end eventually get a new and improved front end with a hybrid [Paul + Donor-bike] front end frame that can take a 20/24 wheel?
When will you put an IGH or one of your N3XX hubs up front? :)
We need to know ;)
 
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Looking good Paul :)
Only from about 10ft away !

Will this back-end eventually get a new and improved front end with a hybrid [Paul + Donor-bike] front end frame that can take a 20/24 wheel?
I suspect yes as the BB will now be to low for this rear end as seat is now raised from:-
Tilt#3 seat height = 11" [ basis for Tilt#5 ]
Tilt#4 seat height = 18"
Tilt#5 seat height = 15" [ almost 2x original Pythons 8" ]

When will you put an IGH or one of your N3XX hubs up front? :)
Well yes , however that is someway down the ' to do list '

We need to know ;)
So do I any idea ?
Paul
 
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So do I any idea ?
If I were blessed with good ideas I wouldn't be here. ;)
Your Mk 5.x can get a nice IGH and you can have a simpler chainline and "shifting at a standstill".
No more cassettes gathering dirt and dust. :)
 
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Tilt#2 = 72 miles - retired - dangerous
Tilt#3 = 272 miles - [semi] retired - proved tilting concept
Tilt#4 = 105 miles

Still riding Tilt#4 although some think odd happened today , what Terry Pratchett would describe as ' headology ' may have occurred.
I have commented in the past about one ride where it all seemed ' bad ' trike throwing me everywhere me not seeming to get the straight line tilting right and feeling at odds with the trike [ fighting it ]
I usually do out in by one route and back by another route so if I feel it is odd over one part of the route I assumed the trike was being odd all of the time ?
It appears that is not true ?
I left mothers and proceeded to my mates for a coffee and natter , riding there no problem.
However I then had an eye appointment which meant I retraced the route near his house about 20 minutes later in the opposite direction to get to Specsavers.
Again it felt ' bad ' trike throwing me everywhere me not seeming to get the straight line tilting right and feeling at odds with the trike [ fighting it ]
Yet all that was happening was the trike was traveling in the opposite direction.
Thinking back to other times where I have felt out of sync with the trike , the problems mainly seem to occur when I have to tilt myself to the left ? and never can I recall it being odd tilting to the right ?
That is weird.



So in the background is Tilt#5


So how is it different from Tilt#4 you may ask [ please ]

partTilt#4Tilt#5
Main frame from ground10.5"5"
Seat front from ground18.5"15"
Top of handle bars from ground22.519"
BB height from ground24"15"
w/b40"38"
seat back angle54'54'
pivot angle53'56'

So BB is just at seat height so that's ok , what is odd handle bars feel way to low and yet the difference between them is the same 4"
So what are we trying to do ?
a) Get the seat a bit lower to improve confidence that we are not shortly going to be taking flying lessons
b) Get more height between the seat and the pivot to see if the trike feels less nervous.



So these ugly spacers raise the seat 3" higher than it was on Tilt#3 and at the same time lowering it 3.5" less than Tilt#4 so achieving a) & b).
Obviously if this works then a more elegant solution will be dreamed up and a definitive trike will be attempted aiming for the same parameters of Tilt#5 with less ' bodged joints ' and from 1.25" tubing in an attempt to reduce weight ....
.. and no don't ask , I have no interest at the moment in it's weight , it has been described as ' adequate ' and if nothing breaks ' strong enough ' for the job ;)

Tilt#5 has been ridden a couple of times around the estate there is a snagging list.
puzzle why the bars seem to low.
brake levers very ' hard ' to pull [ compared with Tilt#4 ]
could do with some primer and paint in case it has to face the winter

all for now Paul
 
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So no riding Friday rained all day.

So got on with new brake mounts for the rear of the SA drum brakes , these are exceedingly difficult to mount I found on the old brake mounts if I attached the back plate anchor screw and did that up first it was impossible to get the wheel on !



So here you can see the back-plate is held on the axle by a pile of spacers [ the nuts and washers ] and the anchor mounting bolt is fastened to a bracket , that just needs welding to the frame and we have it cracked....



So anyone spot the mistake and why one of them does not work properly ?

Yep the clamp is not holding the bracket flush to the frame , only spotted now in the picture AFTER I have welded it , so another failure GOD I HATE THESE BRAKES !!!!!

The problem lies with their construction...



You need to provide clearance for A the operating arm , however the axle bush B is not big enough to be bolted up to a flat surface [ WHY ? ]
Easy you say end the frame at the stud to the left of B's red line , well no because the cable for the actuating arm has to have a clear run from A to C.
You can see that the anchor plate @ C will not touch the flat surface either [ WHY ] even if B is packed out with washer [ WHY ] and to make matters worse the back of the drum back-plate is not flat either ! stopping you taking the anchor plate off and drilling the back-plate to directly mount if on the frame.

Paul
 
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I don't understand why you have this issue, when I don't.
Although my "point "B" is handled differently as I have a QR axle, the other criteria are the same?
What is the height of the centre standoff piece at "B" relative to the back-plates rear face?

I just did a rough measure of my backplates from the surface they are mounted on and the stand-off is about 15mm, if that helps?
 
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I don't understand why you have this issue, when I don't.
We have discussed this many times .....

Although my "point "B" is handled differently
Exactly and there is nothing I can do about that , ie. the cr*p fixing method SA force me to use...


By the time I have added the 2 washers shown here and the fact neither the M12 bolts I use of the ones supplied by SA are a snug fit the back plate can move over 3mm in any direction it chooses.
Despite clamping the back plate tight to the frame AND bolting the anchor plate to it's mounting tab and clamping the mounting tab to the frame , one of the mounting tabs has been welded in the wrong place [how ? ] and when the anchor is bolted tight to the mounting tab it is not possible to get the wheel on ...

Go figure (n)

What is the height of the centre standoff piece at "B" relative to the back-plates rear face?
Depends whether there is any frame to the left of B for A to foul on and what I have to use for packing B out ?

Paul
 
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By the time I have added the 2 washers shown here and the fact neither the M12 bolts I use of the ones supplied by SA are a snug fit the back plate can move over 3mm in any direction it chooses.
Despite clamping the back plate tight to the frame AND bolting the anchor plate to it's mounting tab and clamping the mounting tab to the frame , one of the mounting tabs has been welded in the wrong place [how ? ] and when the anchor is bolted tight to the mounting tab it is not possible to get the wheel on ...
Is it my imagination or... are your backplate tabs completely flat?
Mine have a formed "dogleg" in the steel, so that the mounting tab is stepped away from the backplate.

I think there are 2 solutions available:
1. maybe you need to mess around with the mounting tabs and cut-n-shut a dogleg in there?
OR,
2. Weld a stub of round bar stock (or a longnut) on the inner face of the tab that is long enough to bridge the gap back to the plate welded to the frame and drill & tap it with a thread.
Then bolt through your welded on tab into the barstock/longnut?

This approach removes the need for a bolt-head on the wheel-side of the backplate's tab.
 
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Of course they do. How on earth did I miss-see that. LOL
The strength of yours lies in these 2 nuts :-



They firmly anchor the back plate and allow you to select the distance it is from the frame.

I have an idea.....

Paul
 
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