Yes and I have some , just used what was at hand at the moment...If you use female rod-ends and M12 studding and nuts, can you not get increased angles?
Paul
Delta trike design - constraints and solutions ?
- Thread starter stormbird
- Start date
Paul
I've bent male M10 rod ends in similar positions. They bent alarmingly easily too. I always try to work things to have female rod ends where I can. For the probable upcoming 4ws quad I've located some extra strong M12 units as I had to use male ones.
Threaded rods are ment to bend. The thread is just a wrapped around bending line. A M10 rod is maybe as stiff as an 7mm solid rod.
+ Maddox
Yes I was going to use M12 anyway and do have the female versions , however they have not bent yet in the Python and the forces in the middle are incredible how did you manage to bend some ?
Paul;
Probably through being fat if I'm being honest. They were on the mk1 tilter at the wheels similar to being used as a kingpin pivot. I used high grade m12 male on the mk3 and they're fine.
I didn't bend those rods in bike applications. But Robot Wars has its own hazards.
Using threaded rods as structural elements is contra-indicated.
Using threaded rods as structural elements is contra-indicated.
So having been to see pedal car racing I needed to try a ladder frame mock-up ?
Current inspiration is this , a car from the Royce team
So outside
and inside - so I like the steering and the drive shaft arrangement. These cars are approx 48" w/b and lower than i want to be [ I think ] so plenty of ' figuring ' needed
I stripped the front and rear axles off the main boom mock-up and made the main boom free standing [ probably can't take my weight though ]
I then made a ladder frame the front is dropped 45' and is 5" from floor to allow it to be as short as possible and still clear my pedals , also turns out it is no longer than o/a length of main boom mock-up a big +.
Seems I actually have 3" of pedal clearance so room to manoeuvre ? the dropped part could be 2" higher ? or the ladder frame could be 2" lower etc etc.
Looks like a tube up to the BB would be almost vertical [ unexpected ]
transferred all the important points from the main boom to the ladder front axle , rear axle , seat front mount and seat rear mount.
made a couple of cross pieces up to maintain shape whilst tinkering and tried previous jackshaft cross piece to see where it might go ?
a second tube from the BB would go to this.
Lots more thinking and wood needed then which to build ?
Paul
Current inspiration is this , a car from the Royce team
So outside
and inside - so I like the steering and the drive shaft arrangement. These cars are approx 48" w/b and lower than i want to be [ I think ] so plenty of ' figuring ' needed
I stripped the front and rear axles off the main boom mock-up and made the main boom free standing [ probably can't take my weight though ]
I then made a ladder frame the front is dropped 45' and is 5" from floor to allow it to be as short as possible and still clear my pedals , also turns out it is no longer than o/a length of main boom mock-up a big +.
Seems I actually have 3" of pedal clearance so room to manoeuvre ? the dropped part could be 2" higher ? or the ladder frame could be 2" lower etc etc.
Looks like a tube up to the BB would be almost vertical [ unexpected ]
transferred all the important points from the main boom to the ladder front axle , rear axle , seat front mount and seat rear mount.
made a couple of cross pieces up to maintain shape whilst tinkering and tried previous jackshaft cross piece to see where it might go ?
a second tube from the BB would go to this.
Lots more thinking and wood needed then which to build ?
Paul
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Wow did I only start this about Friday ?
Previous design
new design
I think this looks better [ more polished ] as I am happier copying an existing design than staring at a blank sheet of paper
My previous still had lots of area's needing solutions i.e main frame - BB - seat mount etc etc
So couple bodges to get it out into the sun [ to be addressed later ]
track front 30.5" would be better 28" - 30"
track rear 26" may massage to give me 28"
w/b is 35" spot on
length 56"
seat front 11" from ground - not bad
BB 18.5" - to high for seat height however it can only lower till my heals hit front dropped X member
front X member from ground 5.5" - should be a little higher I think
outer frame members 18" apart
x member forward of seat 7" from seat - for jackshaft
front X member compromise attempt to shorten front , still have ground and heal clearance [ it may work ]
added a piece of wood for BB to jackshaft X member to mount this you stand in the gap between the wheels and place foot/feet over side rail and into gaps either side of rear BB tube.
still no idea if I can actually get some steering control rods into design without either fouling pedals or making it longer , need kingpins before I look at that can of worms labelled Extra Large !
Paul
Previous design
new design
I think this looks better [ more polished ] as I am happier copying an existing design than staring at a blank sheet of paper
My previous still had lots of area's needing solutions i.e main frame - BB - seat mount etc etc
So couple bodges to get it out into the sun [ to be addressed later ]
- no kingpins [ yet ] so simple M12 threaded rod front axle
- BB rough position height not resolved yet
- seat does not have a rear mount yet
- rear wheels simply bolted straight through frame[ may do that in steel one ]
- no steering provision yet
track front 30.5" would be better 28" - 30"
track rear 26" may massage to give me 28"
w/b is 35" spot on
length 56"
seat front 11" from ground - not bad
BB 18.5" - to high for seat height however it can only lower till my heals hit front dropped X member
front X member from ground 5.5" - should be a little higher I think
outer frame members 18" apart
x member forward of seat 7" from seat - for jackshaft
front X member compromise attempt to shorten front , still have ground and heal clearance [ it may work ]
added a piece of wood for BB to jackshaft X member to mount this you stand in the gap between the wheels and place foot/feet over side rail and into gaps either side of rear BB tube.
still no idea if I can actually get some steering control rods into design without either fouling pedals or making it longer , need kingpins before I look at that can of worms labelled Extra Large !
Paul
One of the drawbacks with the twin spar perimeter frame is each wheel is now free to act on the rail it is attached to to try to twist it. With a single spar that twisting force is stopped by the other wheel mounted to the other side of the central rail. It's all but impossible to brace as your feet need that space. The further towards the axle you can get that front crossmember the more it will help resist that force.
Do you have enough room between the wheel and those rails for the wheel to turn enough? It doesn't look enough but could be camera angle trickery.
Do you have enough room between the wheel and those rails for the wheel to turn enough? It doesn't look enough but could be camera angle trickery.
yes a worry , that space looks huge ! it is approx 24.5" long and about 8.5" to BB spar.
I can move the jackshaft X member forward at the expense of making it more difficult to step into it.
I can move the front X member further back by raising the BB and if needed the seat.
I could add a small X member in the same position as in the pervious version ?
That is a ' I hope so situation '
To make the most of the space [ about 5" ] I think I need the kingpin as close to the wheel hub as possible ?
Paul
If you only have 5" between chassis and wheel you're getting a best of 30 degrees of steering. In reality probably less. You'll need 7" for 45 degrees and 8" for 53 degrees as minimums. Keeping the kingpin close will maximise it.
So more musings ?
I inserted the front X member from the mono boom frame under the ladder frame , now the 13" is the width needed to clear my shoes and this position is the distance from the BB to get heal clearance however the ladder frame is 18" apart ? why ? not a clue !!!
So next up is to make 3 more X members only 13" apart and not 18" and re-assemble that should give me approx 6.5" for the wheel to turn also the horizontal piece could actually be added under the rails of the ladder frame if needed for more stiffness ?
Then really need some pedals adding to see what the BB height maybe ?
Paul
I inserted the front X member from the mono boom frame under the ladder frame , now the 13" is the width needed to clear my shoes and this position is the distance from the BB to get heal clearance however the ladder frame is 18" apart ? why ? not a clue !!!
So next up is to make 3 more X members only 13" apart and not 18" and re-assemble that should give me approx 6.5" for the wheel to turn also the horizontal piece could actually be added under the rails of the ladder frame if needed for more stiffness ?
Then really need some pedals adding to see what the BB height maybe ?
Paul
So chickened out and made the new X members 14" apart , well apart from the one I accidentally cut @ 13"
Front wheels still a little to wide @ approx 31.5" track , will fix soon.
Rear track is now currently approx 20" , probably pad that out a little as we go along.
Wheels still through middle of frame side rails so frame is approx 9" from floor , seat front 12" and BB 18.5" [ much to high for current seat height ]
Now 5" between frame and wheel , plus realised wheel rotates about contact patch [ if king pin inclination angle correct ] so maybe a bit more ?
Need to sort BB out next as either:-
it needs to be lower = pedal clearance with dropped X member
or
seat needs to be higher
or more likely both to achieve BB about 2" above seat front height
I started this thread 19th December , if I had stuck to plan A a delta it would probably have been built by now ?
Paul
Front wheels still a little to wide @ approx 31.5" track , will fix soon.
Rear track is now currently approx 20" , probably pad that out a little as we go along.
Wheels still through middle of frame side rails so frame is approx 9" from floor , seat front 12" and BB 18.5" [ much to high for current seat height ]
Now 5" between frame and wheel , plus realised wheel rotates about contact patch [ if king pin inclination angle correct ] so maybe a bit more ?
Need to sort BB out next as either:-
it needs to be lower = pedal clearance with dropped X member
or
seat needs to be higher
or more likely both to achieve BB about 2" above seat front height
I started this thread 19th December , if I had stuck to plan A a delta it would probably have been built by now ?
Paul
But you would not have had as much fun, and this may prove to be very interesting to many people.
It would also have been less effort to use a basic CAD program.
? Only if that is the way your brain works AND you knew how to use the CAD program in the first place.
and of course I have built 3 mock-ups so far .....
My brain likes to see stuff in the flesh and I can compare the mock-up to the existing Python.
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Well I have found 5" !!!
Current pedals added , yes both same length this time @ 170mm have 5" of clearance to dropped X member so what to do with that ?
So it's all about BB/seat height difference , I want about 2"
I think first thing is to raise X member by 1" as currently only 5.5" from ground
Seat will really be 2" higher as there is no mounting hardware in picture
Next lower BB till I have achieved 2" height difference with seat and take another look...
Scope of course to go to 155/150mm cranks if necessary , trying current Python with 150mm
happy Easter all who partake in this sanctioned chocolate eating binge
Paul
Current pedals added , yes both same length this time @ 170mm have 5" of clearance to dropped X member so what to do with that ?
So it's all about BB/seat height difference , I want about 2"
I think first thing is to raise X member by 1" as currently only 5.5" from ground
Seat will really be 2" higher as there is no mounting hardware in picture
Next lower BB till I have achieved 2" height difference with seat and take another look...
Scope of course to go to 155/150mm cranks if necessary , trying current Python with 150mm
happy Easter all who partake in this sanctioned chocolate eating binge
Paul