Amberwolf's Recumbent Tadpole Ought-One (ARTOO)

[AussieJester]

YUP thats the one...and yes Simon (CarvinMarvin) has removed all pics of his design, he is
attmepting to have it mass produced so is keeping the details quiet now.

Best PM Paul D and see if he can send through the diagrams, i havent got them anymore and dont recall the exact method he was using other than it was seas simple...

KiM

[amberwolf]

Will do.


On transmission thoughts, I think that at least for now I will setup a system to switch the motors from series to parallel depending on A) speed and B) steering. It is far easier to do this than to mechanically deal with huge reductions and shiftable drivetrains (other than an internally geared hub).

So series wired for startups and slower speeds. Once past a certain speed, will switch automatically to parallel, and not drop back to series until a couple MPH slower than that setpoint. The hysteresis will prevent the switching system from chattering and blowing stuff up.

I will need to learn to drop the throttle when the shift occurs, so I don't end up with sudden bursts of speed. I will probably put a light and maybe a beeper on there to alert me to an imminent shift, maybe 1/2 second before it happens, which should be enough to react to until I get a feel for it.

Since the main reason I wanted series motors was so that I could get an electronic differential for turns, it means that turning would need to be done at slower speeds in order to get that differential. For gradual curves it may not matter; have to test that. For sharper turns, such as from a N-S road onto an E-W one, I will probably need that differential.



Hmm....maybe a much better idea would be to build up the second 2QD and tweak them both to run identically when matched with their own motors, then use separate controllers with one throttle, compensated for an electronic differential by having a steering sensor that changes the proportions of left vs right motor throttle. It'd be more electrically complex, but also simpler in a number of other ways. It also leaves me with redundant controllers as well as motors and drivetrains, which is a nice feature.

I think I already have all the parts for a second one, including another metal enclosure (from an old external harddisk) similar to the Jensen inverter case I am installing the first one into.

This also means I can leave the Curtis on the CrazyBike2's motor, to which it is more suited (given that motor's short-term power capability).



I could not sleep last night (again, it's a common problem) so in between dozing just long enough to know I dozed as my head hit the keyboard, I looked up tilt-steering (leaning) trikes, all over the web.

I found a little information here on ES, which eventually got me links to links to links to a place called Jetrike, an open-source recumbent bike / trike project. The creator of it has plans and construction notes for a bike and a couple of tested trikes there, and some of the stuff looks very interesting. The most interesting part is that he has run simulations for the designs to see what would "really happen" before actually building anything. And has data tables and stuff for a few critical types of dimensions and how to work them out for a particular design. The trikes are deltas, but he started on a tadpole according to his pages there. I'd be super-interested in seeing what he comes up with.

However, the link to that project is broken, and there are no updates to the site that I could find since late-ish 2007. There is also a discussion link, but skimming thru it's archives I don't see any indication that he has proceeded with that project at all, which is very disappointing, as he did good work on the previous versions, and has hard data on why some things should or shouldn't be done, and how they might be improved to fix problems reported with various ways of building trikes (including fixes for rear-steering trikes, which are notoriously unstable and potentially very dangerous, due to flaws in layout of the tested versions, apparently).

Anyhow, I have many more ideas on a tilting trike, but I am still not confident at all that I could design something around that concept and make it work safely and reliably. Not with the stuff I just happen to have laying around, anyway.

There are others around as well, and many images and a few clear videos of some in action. I may be able to learn enough to actually design one of my own, though first I need to learn enough about the math involved to grasp the solutions in my head so I can come up with stuff without having to actually sit down and do all that math (at which I really suck).


I think I need to just build the thing first and get experience with a trike, then start working out version two that will have more features on it, probably including tilting.

I might even go ahead and build a pedal-only trike first, just so I can get that part working, and get a feel for ergonomics of the design based around my riding, and THEN work out a replacement for the front wheels/forks that lets me use the motors on there. I've been putting off this trike thing for so long because I didn't have this or that or a way to figure such and such out, etc., and I am really wanting to just get it STARTED!

[amberwolf]

Well, life, work, and some injuries and illness have kept me from doing much on the trike for a bit, but have still been pondering things in the back of my head.

In the meantime, Spinningmagnets has sent me three internally-geared hubs rescued from the dump to pick thru for the two I need for the front wheels, and forward on the one I don't use to Enoob.

There are also some interesting reflectors, made in Germany.

DSC02499.JPG (135.12 KiB) Viewed 1413 times

Two of the hubs appear to be old Sachs 3-speed Torpedo Dregangs, stamped 36 (for 36-hole).
EDIT: Some info threads I found about it, including this one with a reply from Sheldon Brown:
http://www.cyclingforums.com/rec-bicycl ... eeded.html
some service manuals:
http://vancruisers.ca/tech/manuals/sram ... ce-manuals
This page: http://yarchive.net/bike/torpedo_hubs.html describes the black-shiftered units I have here as potentially unusable for power applications, but I'll have to open them up to see if the parts it notes are the good kind or the bad kind. Apparently if the shifter is red or blue they're known to be good.

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which also have brake arms attached, so they have coaster type brakes inside.

They have the shifters still attached.

DSC02501.JPG (123.1 KiB) Viewed 1412 times

Both seem to function normally, and seem to be well-oiled.


One I haven't found the manufacturer of yet, but are only marked "333", Three Speed Hub F, and a USA Patent number.
EDIT: Apparently this is an old Shimano hub, according to Sheldon Brown's site. http://sheldonbrown.com/shimano333.html Indications are it might not be usable for motor power.
Found a flickr page that shows it mounted on a bike, so a shifter can be fixed up for it http://www.flickr.com/photos/34767893@N ... 466850918/

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It was dried out inside from the feel of it, and kind of gritty-feeling when rotated, so it'll need to be opened up and checked out, then relubricated before using it in anything.

It has a little problem with the shifter input, with a crack in the chromed metal, but still functions. That crack may not ever keep it from functioning, but a hose clamp around it would probably prevent further issues.

DSC02504.JPG (96.19 KiB) Viewed 1410 times

The only potential issue I see with the Sachs hubs is that due to the coaster brake mechanism on the left side, the hub shell is completely open on that end for rotation, so there is nothing except the spoke flange to affix a disc brake rotor adapter to. Because of the size of the flange, that'd mean completely boring out the rotor itself, which might not be possible depending on how it's designed (due to most of them having large amounts of material already removed for lightening them up).

I might be able to use some old 5.25" harddisk platters, though, bored out in the center and then mounted on an adapter ring that's fixed to the spoke flange. Probably just have to remove the media surface first, for better braking (otherwise it's an awfully smooth surface).


There is another internally geared hub on it's way, due here Wed or so, from Ejonness, don't have any details on it yet. Probably similar to the above.

[amberwolf]

The other hub arrived, and is also a Shimano 333 hub but is in better shape than the one above.

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Probably this one would be better to forward on to enoob than the other one, as I think it's in better shape, but I need to take them all apart, clean and relube them, and test them first. No point in sending on stuff that's not gonna work.

At a bike swap meet, I also found--along with a junkbox of stuff (see the DGA Mk II thread for pics of all that)--this Sturmey Archer 3 speed AW hub, and it's shifter and handlebars just like the ones on my CrazyBike2:

sa 3 speed hub.JPG (96.07 KiB) Viewed 1335 times

Seems to be in ok shape, from 1978 if the 78 stamp on it is a year.

[12p3phPMDC]

Amberwolf,

Starting to build a nice collection of 3 speeds there...

It appears that SHimano has kept up with the pushrod shifter design, whereas SA has
kept the pull rod/chain design over the years.

How does the SACHs shift?

[amberwolf]

Starting to build a nice collection of 3 speeds there...

From never having even touched one in my life to having five in my hand within two weeks...yeah. Hopefully at least two of them are useful for the trike's front wheels. I think the SA is probably good, and the Sachs seem to be, too, at first check. The second Shimano probably is, but the first one has that crack in the shifter.

I'd like to use a third one that doesn't have to work the same in the rear wheel, too, so I can have three times as many gears for pedalling when I need it, which will probably happen a lot during the first experimental stages, at least.

Once I am sure I have at least two that work, I can send along a good one to enoob for his experiments.

Also, I am considering using one for some experiments regarding the "IVT" based on a planetary system with two motor inputs, and output on the planet carrier.

It appears that SHimano has kept up with the pushrod shifter design, whereas SA has
kept the pull rod/chain design over the years.

Yeah, it's interesting that they are different. I think I like the pushrod better, because I could rig a shifter for it easier. Well, maybe. I only have the SA / Sachs type shifters, but perhaps they will work (in reverse) on the Shimano.

How does the SACHs shift?

Appears to be *exactly* the same as the SA. I suspect one of them duplicated the other, though I don't know which company made theirs first. Maybe both copied someone else.

[12p3phPMDC]

Ahhh......planetary goodness!!

I suspect if you lock out the freewheels like the S3X, then coupling a CVT and 3 speed together may produce some interesting results....

[amberwolf]

Well, I don't have a CVT (and using the 3speed as an IVT won't make it one), so that's something I can't really try.

But if one of the 3speeds will work as an IVT, with one motor input on sun (axle), one on ring (hub), then the planet carrier when in 1:1 should give me a variable-speed output based on the difference in speeds between the two always-fast-spinning motors.

Then I can convert speed to torque via another method after this if I have to.

[Miles]

amber,

AFAIK, an IVT is a sub-type of CVT that works down to zero output speed.

[amberwolf]

Normally, yes, however this IVT doesn't work like a normal CVT, which converts speed to torque or torque to speed--all it does is take the difference in speed between the two motors and output that, at the same torque level that is input to it.

So that's why I'm not calling it a CVT. Maybe it shouldn't even be called an IVT. If early computers had not already used this name, I would call it a "difference engine".

[12p3phPMDC]

http://cvt.com.sapo.pt/ivt/ivt.htm


Check this page out ..... pretty cool IMO.

[Miles]

Good find

[amberwolf]

Yeah. Lots of possible variations, including our two threads here on ES:
viewtopic.php?f=28&t=10998&start=0
viewtopic.php?f=2&t=15618&start=0
and one on DIYEC:
http://www.diyelectriccar.com/forums/sh ... 41164.html
which has the resolution of why this particular idea won't do exactly what I'd like, but should still be useful.

Then there's Naeem's new thread:
viewtopic.php?f=28&t=16329&start=0
that should prove interesting and useful.

[Miles]

This is the most promising one I've found, so far....
viewtopic.php?f=28&t=16386

[amberwolf]

Unfortunately the person does not respond to contact attempts; I ran across that one a little while back and thought it quite interesting.


AussieJester's package arrived today, so now I have the crucial parts for disk brakes, and a Watts Up to experiment with in any way I need to (unlike the Turnigy that I need to keep intact). Plus some extra long brake cables and a dual brake lever, all of which ought to come in handy for the trike.

Seeing the parts in my hands makes it a lot clearer exactly what I will need to do with them to adapt them to my motor-powered IGH front wheel ideas.

Now I need to figure out how to secure the rotor to the IGH. The Sachs hubs are really going to be a PITA to try to do that to, while the Shimano hubs have a solid enough endpiece on the left that I could probably machine a keyway into it and make a rotor adapter that screws into the spoke flange but also acts on the strong core of the hub that way.

The Sachs hubs have a totally separate endpiece that is part of the coaster-brake arm setup, so the only place I can secure any adapter to is the spoke flange.

What it might come down to is fixing the hubs so they have no freewheel, then putting the brake rotor on the sprocket mount along with the sprocket itself, or putting the rotor on the motor's axle hub instead, and having to deal with the braking forces going into the drive chain.

I started working on the damaged Shimano hub, and got it most of the way apart for the core, but found I can't get the freewheel's ratcheting ring loose, so I can't take the planet carrier out, and thus cannot put it back together either. There are two small bars that insert thru the axle in a slot that fits either side of the left end of the PC, which are what the spring and pushrod push on either side of to do the shifting. But one of them has to be inserted on the left end of the axle, which can only be done with the PC out of the hub, as there is not enough space to fit any tools that could hold onto the bar well enough to manipulate it into the slot from the outside, between the bearing ring and the axle itself.

So...until I can make a tool to remove the freewheel ratchet ring, or figute out a way to use an existing tool to do it, without damaging the ring or the hub, I can't put this one back together, nor can I risk taking the other one apart to check it out or clean/lube it beyond just adding some oil via the dropper hole.

I'm still cleaning the external gunk off a Sachs hub to check out what I can do about the left end of it to put the brake rotor on there, since I won't be using the coaster brake anyway.


Now, as for the internal construction and condition of the Shimano hub, it appears to be in decent shape, though there is obvious wear on the tips of all the freewheel pawls. Not much on the gears themselves, at least on the sun and what I can see of the four planets. The bearings are in good shape, as are their races, but they did have a lot of dried gunk in there that used to be oil or grease.

Some WD40 and a brush got most of that out, then I soaked the whole thing in hot soapy water to wash out what was left of the oily mess. Even though I can't yet reassemble it properly, I repacked the bearings with the red high-temp grease I use on my other bike bearings, which at least doesn't melt and run just sitting in the hot Phoenix sun, unlike the regular yellowish "axle and wheel bearing" grease I have tried from automotive places.

I reassembled it without the two bars, and put the whole thing in a plastic bag so it will stay together until I get a way to put them back in.

I forgot to take pics of it while apart, so I'll do that when I go back to it. And try to remember to do it for the Sachs as I clean it up. At least the Sachs I have a disassembly manual for, found in PDF form online, so no surprises when I start working on it.

[Miles]

Unfortunately the person does not respond to contact attempts

I didn't have any problem. You won't learn anything about how it works until the patent is published, though.....

[amberwolf]

Mmmm...I have trouble contacting lots of places; it's probably the way I write or talk--they just don't want to bother with me since I sound like I'll take up a lot of their time (probably right, too).

Unfortunately also seems to be an issue with finding employment, but shortening my written messages and reading from carefully edited scripts I write before I call doesn't seem to help much either, especially once I have to talk to them live.

[amberwolf]

haha...i took an involuntary nap and when i woke up i found a reply from them in my email. wierd synchronicity that they'd choose to do so within literally an hour of talking about them. where is that xfiles smiley...
<.<
>.>
O.O

[Miles]

[amberwolf]

Well, I just had the most brilliant idea for how to do the front drivetrain on ARTOO, using the disk brakes, IGHs and the gearboxed wheelchair motors, just as I woke up from another involuntary nap.

Then I promptly forgot what it was, just as I was putting pencil to paper to sketch it out.

The good news is that once I think of something like that, it's almost always lurking right around the corner, and eventually like a sulky cat it will come back to me.

Eventually could be a long while, though. Right now, I feel like I'm on the edge of another nap. I'm sick and tired of being sick and tired.

[amberwolf]

still havent' rememberd the idea yet.

viewtopic.php?p=242212#p242212

[amberwolf]

I'm still working on this project; just been stalled with being ill for a while (am again, now, not as bad), and trying to figure out how to do all the little things it's going to need, especially the front drivetrain and brakes, before I begin building it (so I don't have to redo things as much).

Also still making decisions about the geometry. Might keep it shorter.

[amberwolf]

Crosspost from another thread discussing shifting for the motors:

I really wanted to use a Sram DualDrive on Woody to help with the chain path but they're so darn expensive and I was having a hard time finding a Strumey Archer at a decent price. I've never even seen a DualDrive and it's probably been around 4 decades since I've been on anything with a Strumey but I assumed if I went that route I'd need a little more precision shifting and would probably need to go to some kind of stepper motor control to get the precision.

I got lucky on the hubs and got some from the city dump via Spinningmagnets and Ejoness. They're old and apparently well-used Shimano 333's and Sachs types (2 of each). I also have an SA from the same era (70s or 80s) found at a bike swap meet not long after I got those. I'm still working on how to build a disc-brake adapter for them, too, probably going to layer some aluminum panel scraps together and cut on the lathe, bolt them to holes drilled between the spoke holes on the flanges.

I'm not sure exactly how I'd do the shifting motorization, but probably I'd count the number of turns needed to shift it one gear, then build a little incrementable/decrementable counter and set it up to turn off the motor after that number of turns. So it would be just commanded to shift one gear at a time with a pulse from the shift control (be that a button on the bars or an electronic command). It'd be easier to do with a PIC or AVR or something, I'm sure, but I already have a bajillion old boards with 74xx series logic gates on them, so I can use those for free instead of buying an MCU kit, and then having to figure out how to program it (I suck at that kind of stuff). I'd probably just dead-bug wire up the gates and stuff.

What is your idea for taking care of the automatic side of things on your trike? Something like the LandRider or are you leaning towards something electronic?

Not familiar with the LandRider; looked it up on google and found it uses weights to shift, I think. I'd probably instead be basing it on current draw from the motor, since the front wheels would both be motorized, and the pedals only run the rear wheel. As the current draw increases beyond a setpoint I'd have to determine, it'd trigger a shift down. As it decreases below a slightly different (lower) setpoint, it'd shift up. I'd likely also put +/- buttons on the bars, that would override that automatic shifter until I press a "cancel" button.

The current measurement can be done with a simple shunt in the motors' power path, and amplify that with an op-amp, with a couple of comparators to determine if it sends a shift up or a shift down pulse, which can trigger a 555 for whichever one it needs to do. As long as the shunt is in the path leading to both motors, before it splits to feed each separately, it will measure total motor power and shift both of them at the same time. I just have to put enough hysteresis between up and down for it to not try shifting all the time, especially under the following conditon:

To keep it from having to shift under load I'll probably also put an interrupter to the throttle circuit, which will momentarily take power from the motors during the shift, then reapply it just like it was before. That will cause a current surge so I have to be sure that the current measurement/shifting doesn't shift until the current has been high for a certain period of time. Also the current drop when power is cut has to be prevented from shifting up.

This whole method might not work at all, but since I am mostly trying to have the gears there for it to be more efficient rather than to run at any particular speed, it should do what I am after. I think.

I've also copied this post over to the ARTOO thread, so I won't forget about this later on when I get back to the fancy stuff for that trike.

[amberwolf]

Been pondering disc brake rotor adapters and such. Basically, it would be a ring that conforms on the right side to the surface of the hub, including spokes as they lay against the spoke flange. Holes would be drilled between some of the spokes in the flange, along with the ring, and they'd be bolted together. The rotor would bolt to the ring just like it would the thread-on adapters for flip-flop hubs.

So whatever I use for an adapter will be based on a solid 3D model made for CNC machining of the ring.

The Sachs hubs (which are built with coaster brakes in them already) are a problem--without some major alteration of the left side of the hubs, I just don't see how I can get a rotor on there. At the least I'd have to leave off the entire torque arm and cover for the brake end. I'm not yet sure if that leaves exposed bearings or whatnot, I have to check the disassembly manual first.

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The Sturmey-Archer is easier, but it's curvy endcap is difficult for me to model in 3D in negative form.

DSC02677.JPG (26.27 KiB) Viewed 693 times

The Shimano 333 hubs are the easiest. They've got a cylindrical section and then a simple cone section, then down to the flange.

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I've also got ideas to test the adapter idea using some sheet aluminum scrap I have (old rack panels and such) by making some rings to bolt to these two aluminum hubs, which are just regular bike hubs off the Schwinn Sierra.

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I may instead use some older 10-speed steel hubs that already have ellipsoid holes in them from the factory, so I am not drilling thru these. In either case, I'll just drill the six rotor holes all the way thru the aluminum scrap and then the hubs, using the rotor's existing mounting holes as guides. Then bolt the rotors, rings, and hubs together and see how they hold up.

Of course, I'll have to weld on some caliper-mounting points first, and I'll use an old 10-speed fork for that rather than the nicer-looking Schwinn Sierra fork. For the rear, I'll weld to the Trek frame (that is the rear part of the cargo bike the Sierra is becoming part of). Then I'll know if the ideas are sound enough to use on the trike, or if I'll have to use the 3-speed hubs outside of the wheels, and use regular disc brake hubs on the wheels themselves.
viewtopic.php?p=261352#p261352

[amberwolf]

I've finally seen a Landrider in person. It does look interesting, and if I'm lucky I'll get a chance to stick a motor on that drivetrain to see what happens. If I was just pedalling it, I would take a while to get used to the autoshifting--I see why they are not popular with regular cyclists; it's kind of unpredictable at first and throws you off cadence.

But with a motor doing the real work, and me just pedalling to help, the sudden changes in torque would not be a big deal, especially if my cranks were freewheeled from the motor.



Some thoughts on the 3speed hubs and braking below, originally posted in another thread today but figure they belong here too:


I wanted to use the coaster brake feature of a pair of Sachs 3speeds Spinningmagnets sent me, but haven't figured out a good way to do it. I'd either need contactors to reverse the motor connections of my brushed motors, or a full-bridge controller. Neither one is particularly appealing, though the controller solution would require less engineering at my end, since I would not have to deal with spindown, etc.--it would do that for me with just a signal on the Reverse input line (from the brake lever in this case).

Assuming of course that the controller was well-engineered, rather than leaving it up to the user to ensure all conditions necessary for reverse were already met before engaging it.

I would still need a little electronics outside the controller though. A little circuit that cuts off the regular throttle input, and puts it's own throttle control input instead, immediately after the Reverse input is triggered by braking. That way the motor is not accidentally triggered full blast in reverse, breaking stuff inside the hub, but is held in reversed position by minimal throttle until braking is stopped.

That gives only full braking. If I wanted to modulate the braking force, I would need to monitor the brake lever position, and use that as the throttle input instead of a fixed low-% of throttle.

It gets complicated pretty quick, so I decided it is easier to figure out how to mount disc brakes onto the hubs, or use rim brakes, than it is to deal with the coaster brake by motor power.


I did have an alternate mechanical braking option using a rod or cable activated manually, but it would require rotating the entire hub's axle/torque-arm forward while maintaining it's anchor to the frame to prevent spinout. I don't feel confident enough in the ways I have to make the parts to be sure it wouldn't fail under use, compared to a simple fixed dropout as it was intended for.


Since a power or controller or motor failure would also cause zero braking ability, that was a further motivation to skip the motor-activated coaster idea and go right to the fully-mechanical rim or disc brakes, plus a mechanical brake on the pedal-only wheel.