VK3CKC's eLecTricks Trike Design and Build.

Joined
Feb 20, 2013
Messages
789
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
Thanks. I thought it came up quite well myself. I never went any further with it but enjoyed the relatively short learning time. I decided to get on with the build. Once it is all finished, I may start committing it all to CAD - just for the experience. Depends on what else occupies the time - like riding the trike.
 
Joined
Feb 20, 2013
Messages
789
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
I thought that the weight of the Timber Wolf rear end was more than I wanted and decided not to reuse it. In any case, I wanted independent suspension on this one. Pillowblock bearings would still be used to support and locate the axles on the suspension arms.

I cut two longer-than-required (a very useful dimension) lengths of 40mm sq. tube, drilled holes through one end, removed the suspension arm bearings and tubes from the aborted Timber Wolf build and attached them to the new suspension arms. The pillowblock bearings were bolted to temporary mounting brackets on each of the arms. Two “droppers” were cut overlength and were connected to the suspension arm bearings with a suitable bolt.

To make transport easy, I decided to keep the rear track the same dimension as my Warrior trailer frame so that I would not have to change anything if I decided to transport one trike or the other. A longer-than-required length (that very useful dimension again) of 5/8” rod was purchased for the rear axles.



I needed the two wheels before I could progress too far. I could not use the wheels made for the Timber Wolf as they are welded to the axles. Mine were going to be easily removed but still driven by the axles. That meant that the wheel hubs had to be hollow and a neat fit on the axles. I had worked out that I could weld wheel mounting flanges to the axles at the appropriate position and use four studs projecting from the flanges through the inside wheel spoke flanges so that the wheel could be axle driven.



Using a paper template, I cut four spoke flange discs from some sheet steel, bolted them together in a stack, spun them in a drillpress and rounded them off with a flap disc. I drilled the spoke holes, a 5/8” centre axle hole while they were still in the stack and welded a nice fit piece of round tube between each pair.

The wheel mounting flanges came next. These were basically copies of the wheel spoke flanges and the same fabrication process was used. I drilled the wheel stud holes while they were still in the stack. I countersunk one of the holes so that they could be assembled in the exact same position if their drilling was slightly off and matched them to the wheels. After placing them on the axle rod, it became obvious that they could not butt up against the wheel hub as that would press against the ends of the spokes. A smaller diameter spacer disc fixed that problem. Placing the wheel mounting flange spacer discs and wheel hubs on a short length of 5/8” rod allowed me to drill through for the wheel studs. I then disassembled a Timber Wolf wheel and laced its rim to one of my new easy-fit hubs. This was soon followed by the other wheel and they and their support components were loose-fitted to a single through length of 5/8” rod along with the four pillowblock bearings.
 
Joined
Feb 20, 2013
Messages
789
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
The mounting holes for the pillowblock bearings were too far apart for mounting directly to the swing arms arms so I tack-welded four mounting tabs for them. This allowed me to determine the approximate track width by placing the assembly on the trailer frame.

The rear suspension mounts directly to the cargo bay framing. I had to start somewhere so I welded two short crosspieces to a length of xxmm square tube that was longer-than-required for a tow hitch that would run from the seat post to the rear. At this stage it was only to hold the suspension arms together.



My next task was to cut a length of 40mm tube for the front boom. I used the same measurement that I have often used – longer-than-required. A 34mm hole was step-drilled through what would become the front end. A front fork and headstem was removed from a donor bike, the headstem disassembled and prepared, and was soon fitted to the drilled hole. A front wheel was scrounged and it soon started to look like a trike.

 
Joined
Feb 20, 2013
Messages
789
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
The seat post is the bit that connects the front boom to the rear, so it had to come next. A short, yeah, you guessed it, length of 40mm tube was cut for the seat post. It didn’t have to be this strong but, being the same size as the front boom allowed it to be easily squared up. However, exactly where on the front boom would it have to be fitted? Calculating back from the front wheel, I had to allow sufficient pedal clearance from the wheel at all steering angles. That fixed the bottom bracket position. The usual inseam measurement determined the seat position. The seat position determined the seat post position.

To be safe, I made up two side plates to bolt the seat post in position for finessing. The front seat bracket was purloined from the now stacked-in-the-corner tadpole and bolted in position with a few adjustment holes.



The temporarily movable seat post bracket image is upside down but you should get the idea. The metal I used had a convenient lip that was used to advantage under the boom.

The tow hitch was clamped to the side of the seat post for overall length determination. The tow hitch is narrower than the seat post, saving weight, and I pondered on how I would go about connecting it. I carefully cut a hole in the rear of the seat post, slipped the tow hitch inside and tack welded it in place. After reassembling it, I placed it on the trailer frame. A delta is longer than a tadpole and I had a length limitation determined by what I could fit on the trailer. It fitted but only just. I shortened it by 55mm the next day. It made all the difference and is really about as short as I can make it without encroaching on the cargo bay more than I would like.



The seat post was eventually welded to the boom.
 
Joined
Feb 7, 2008
Messages
2,719
Location
Nottinghamshire England
Nice fast work :)

Is the suspension to be trailing arms ?

Interested in how your detachable wheels work out , as I suspect your method could be used to mount ready built wheels to a delta making the build process easier and faster ?

The seat post looks a bit laid back ?

You don't seem to have any clearance between the lower head tube cup and the frame , pictures a bit small however it looks unwelded at mo ?

Won't it prove a bit hard to mount with such a steep main boom angle ?

Sorry for questions just curious ...
 
Joined
Feb 20, 2013
Messages
789
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
Nice fast work :)

Not so fast work, more like fast write-up. I have kept notes and am now bringing everything up to date.

Is the suspension to be trailing arms ?

The suspension is what might be more correctly termed transverse arms. They pivot on bearings from near the centre of the trike under what I call the tow hitch. All will become clear as things develop.

Interested in how your detachable wheels work out , as I suspect your method could be used to mount ready built wheels to a delta making the build process easier and faster ?

The wheels are a cinch - as long as the four studs are strong enough to drive them. Surely they will be. I will only end up stranded for a little while if they break, but I don't see that happening. I'm sure the idea is sound but needs to be tested yet - as it will be as soon as it is rideable,

The seat post looks a bit laid back ?

It may be, but the seat position and rake will be adjustable. A bit hard to get angles right when it can't be readily sat on. I'm trying to keep a laid back approach to the build. As the bottom front of the seat is mounted to the front boom and the top rear mount will connect to some bracketing in the cargo bay or attached to the seat post, the angle of the seat post is largely trivial. Its main purpose is for connecting the front boom to the higher cargo bay framing.

You don't seem to have any clearance between the lower head tube cup and the frame , pictures a bit small however it looks unwelded at mo ?

There are a few things associated with the build that are waiting on other things before completion. That is one of them.

Won't it prove a bit hard to mount with such a steep main boom angle ?

Possibly, but I wanted to keep the COG as low as I could. The seat isn't on there yet and that will change perception a little.

Sorry for questions just curious ...

No need to be sorry for the questions. They are welcome and that is what it is all about. There are a couple more surprises to come. Hopefully none of the surprises are for me.
 
Joined
Feb 20, 2013
Messages
789
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
I've got in early with this update. Most things are still only tacked together and will be for some time. It's much easier to undo and re=position that way.

A design change occurred at this point. I reasoned that there was sufficient room and clearance each side of the main boom to fit a freewheel sprocket to each side of the mid-drive and changed the rear suspension to one of equal length swing arms. This would make their mounting easier.



After a final check on track width dimension, the rear suspension was disassembled, and the various components were moved to their final equal length swing arms positions on what was still a single axle. The whole assembly was then moved as far forward as possible and re-welded to the tow hitch.

The next item to get some attention was the steering and it was here that my own design took over. I had briefly considered the steering column arrangement used on the ComfoRider but decided on some modifications. My design still has a rotating column but it is much shorter and runs through the main boom at a comfortable position (not yet determined) in front of the seat. The column will still tilt upwards for unhindered entry or exit by a universal joint that I had earlier set up for the tadpole version. Stainless steel cable will be wound at the bottom of the column headstem, continuing to a bespoke pulley on the top of the front fork.



I thought I would add a bit more so that Popshot won't have to post any obvious questions. Be patient.

A pulley fixture for the ends of the cable will enable the push-pull operation to steer the front wheel to the left and the right at up to a 90 degrees. The cable that is wound/unwound at the end of the steering column pushes/pulls the left/right side of the front wheel fork to steer the wheel in the required direction. The easiest and smoothest way of providing this action is to pass the cable around a pulley. The size of the pulley relative to the size of the cable winder will provide the appropriate steering ratio. A brief experiment revealed that there will be room for the mechanism but there may be a requirement for simple guide pulleys to ensure that the cable only runs close to the main boom in order to clear the pedals, etc. An anchoring mechanism needs to be provided to ensure steering integrity. A method of cable tensioning was devised and will be installed after I make sure the steering will work OK.

I temporarily clamped the steering column headstem to the side of the front boom at a convenient spot for checking clearances. The bottom bracket, or a substitute for it, was also clamped in position to ensure that the steering cable would not be fouled. The front headstem is still not welded in position as I will have to shorten it and adjust the height, etc. If you look to the rear, you can get a glimpse of the front seat bracket in the image above.
 
Joined
Feb 20, 2013
Messages
789
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
Why not continue while I am at it? I have nothing else to do as I nurse an extremely sore and uncooperative muscle above my left hip resulting from too much bending over the front wheel.

Two discs of around 120mm diameter were cut from a kitchen cutting board with a jigsaw. Great stuff, that but you have to take gentle steps. If you don't, the jigsaw blade heats up, melts the plastic, deposits it in the cut behind the blade and it also piles up in font, obscuring the cut line. Patience is required. Their perimeter was smoothed by bolting them together through their centres and rotating them in the drill press, my simple, vertical lathe, to abrade their edges. Not too fine a point was placed on this as there was no need. That was the easy part out of the way.

Next came the process of trying to make a very shallow groove around each disc's perimeter for the cable to sit in. A small, sharp, wood chisel may have come in handy here but those that were given to me some 50 years ago could not be readily found for some reason. As the material is pretty hard, the file kept slipping off. What to do? I cut three larger discs from a sheet of thin steel plate that was once a microwave oven cover. These were also rotated in the drill press to smooth their edges. They were then bolted in a stack - steel, plastic, steel, plastic, steel - to make up a dual pulley. I placed this in the drill press and used a round file to put a slight groove in each of the plastic discs. It was easier this time as the steel discs made the file stay centred. The reason for the dual pulley is to keep the two steering cable ends separate so they do not rub together. The shallow groove is to keep them away from the steel discs and not fall off the pulley.



The steering pulley required mounting below the main boom. To do this, it had to be mounted as low on the front fork stem as possible. The lower race of the fork stem had to fit inside the bottom headstem cup. The thickness of the double pulley did not ordinarily allow for this. Overcoming this problem required the top pulley centre hole to be opened to a diameter that would allow the headstem bottom cup to sit comfortably inside the top of the pulley. The hole through the pulley had been drilled to the maximum diameter of my step drill so I had to open it further with a half round file. It only took a few minutes for a clearance fit. I will show more details at a later milestone.
 
Joined
Feb 20, 2013
Messages
789
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
Two L brackets that I purchased more than a year ago, just because I thought they would be handy, firmly attach the pulley to the top of the fork. They are secured in place by the front wheel brake mounting bolt and two of the small bolts holding the pulley components together. I trimmed the rearmost bracket flush with the outer pulley disc but the front one will provide a convenient mount for a headlight and/or a camera. The caliper brake will have to be shifted to the front of the fork to allow its cable to not foul on the main boom as the wheel is steered.

There is a requirement to keep the steering cable close to the main boom at the front wheel end to avoid conflict with the pedals and the e-Assist motor. I had contemplated a small pulley each side of the boom but did not see anything suitable at two stores that I visited at the time. This may have been fortuitous as I came up with a possible simpler arrangement if I don’t happen to find some. This involves using two bearing races mounted horizontally to act as pulleys. The bearings will rotate with the cable action and provide the required guidance. If necessary, flanges could be used to ensure that the cable ends do not run off the pulleys but, due to the short distance involved, I don't think this will be a problem as the cable should not wander.

The headstem that I intended to permanently use was temporarily clamped to the side of the main boom roughly near where it will be installed. The cable was threaded through an already existing horizontal hole at the bottom of it - for convenience if nothing else. One end was wound around the shaft a few turns below the hole, taken to the right hand side of the bottom half of the pulley, with the wheel pointing straight ahead, wound around to the left side, poked through a hole drilled in the plastic in to where its fixing bolt will eventually be, pulled out through the bolt hole and secured under a nearby bolt. A few turns of the remaining half of the cable were then wound on the steering column shaft above the hole in the shaft, continuing the wind direction of the previous wind, taken forward to the left hand side of the top half of the pulley, wound around to the right side and terminated near its mounting bolt in the same manner as the other cable end.



Ignore the horizontal bit at the bottom. It is a remnant from something else.

Now, for the test to see how it would work – or not. The position of the column headsteam was changed to tighten the cable as its tightening mechanism did not yet exist. I was pleasantly surprised at how little effort was required to steer the wheel. It was possible to operate the steering with just a thumb and forefinger rotating the steering shaft. There were two complete turns from lock to lock. Perfect!

I decided it was necessary to devise a means of keeping the upper cable winding separated from the lower. I cut a separating ring from the rapidly diminishing kitchen cutting board, placed it on the shaft, threaded the cable ends above and below it and refitted the cable to the front pulley. Other than being a firm fit, the ring is not secured to the shaft. The cable should always hold it centred. Problem solved.

 
Joined
Feb 20, 2013
Messages
789
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
The steering test being a success, it was time to consider completing the cable tension adjustment mechanism and ready the headstem for permanent fitting. The surplus headstem attachment was removed. The cable is really a little too thin and will be replaced with a slightly thicker one later.

It turned out to be not possible to route the steering cable properly with the pedals and assist motor under the front boom. The cable could easily clear the pedals but not the motor which is wider and will be in the way. It is just as easy to mount them above the boom out of the way and this position is closer to the recommended height above the seat for recumbents in any case.

Before I got too carried away, the preceding activities awakened a muscle problem that had plagued me a few years ago and all construction activities, except for my brain, are on hold. No construction has occurred since July 16th. I have prepared notes for what is planned but they will have to wait as there is a fair chance that they will be altered as the build progresses.
 
Joined
Feb 20, 2013
Messages
789
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
Laying around unable to do anything leaves more opportunity for brain activity and I got to thinking about the mid-drive design. My requirements are for the rear wheels to be separately driven from the mid-drive close to each side of the front boom. There will be a standard cassette on the right end of the mid-drive for drive from the front chain. What form will the mid-drive take?

The basic requirement is for a single shaft with a number of input sprockets (cassette) on its right end, an output sprocket next to them, and another output sprocket of the same size, on its left end. As I saw it, I had two options:

Option 1: The more difficult route might be to use a 5/8" axle rod and try to fit the required input and output sprockets. The shaft would require support bearings but it could be fitted through the main boom. Threaded collars could be used to mount standard freewheels and/or a screw on cassette. The cassette might not be as easy and might require access to some machining that is not available to me at the moment - not possible with current social restrictions. Costs also start to add up with purchasing collars, etc.

Option 2: This option could use a modified version of what I had used on the Warrior and had planned to use on the shelved eLecTricks Tadpole build. First, it requires the right side half of two rear wheel hubs. Joining the two halves together would provide mounting for two modified rear wheel cassettes - one on the right end and one on the left end. The right end cassette would be modified by shifting one of its higher gear sprockets to the inside of the lowest (largest) sprocket, with a spacer, to provide output drive to the rear right wheel. The left end cassette would need only one sprocket fitted, to provide output drive to the left rear wheel. The output sprockets must be both same size. The mid-drive would then be secured in a bracket bolted to the main boom.

The shifting of one of the input cassette sprockets on the input cassette should not be noticed in actual operation as there is no indexing required with the Hilgo gear selector. There is an added benefit in that the drive ratio to the rear wheels can be fine-tuned by the choice of appropriate output sprockets. The two output chains (mid-drive to rear axles) remain captive to the mid-drive output sprockets and no shifting is required.

Option 2 appeared to be the best choice and I had to explore it further.

What happens if I can't find two steel hubs in my collection to cut and weld together? This is a very likely possibility and it occupied my thinking for some time before I came up with what should be a workable proposition. If I was to make a special hub, similar to my rear wheel hubs, with two flanges and a larger diameter tube between them, I could insert two right-hand-side non-steel hub halves into that special hub and bolt them in place with small bolts through their spoke flanges. There would be no extra work in fitting the cassettes and the mid-drive could be as wide as is needed. It seems like that should do the job nicely.

Next job for the brain is to come up with an easy way of fitting freewheel sprockets to the rear axles so that they will still be removable and I think I have that sorted as well.

I’m looking forward to getting back into it in a day or three.
 
Joined
Feb 7, 2008
Messages
2,719
Location
Nottinghamshire England
Hi there

Option2 , won't one of the free wheels unscrew ?

Free wheels also screw into the right hand cups of a BB shell ? maybe easier to find and weld than 2 wheel hubs ?

On your rear wheels that will be removeable ? how do you intend to keep them snug against the drive flange and stop them coming loose?

Keep up the good work ....

We are watching ...
 
Joined
Feb 20, 2013
Messages
789
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
Option2 , won't one of the free wheels unscrew ?

You confused me there. I changed the first response after I realised that I had changed what I was going to do on the mid-drive. I changed the second one when I thought you were referring to the rear axles. I changed it again when I realised you were talking about welding wheel hubs.

Mid-drive: Welding two right rear hub halves together and fitting a cassette on each of them with re-ordered drive cogs, will work as the front chain will drive the right side, and the right output cog will be fixed to that cassette which will drive the right rear axle. The rotating hub will then drive the left side cassette, which will then drive the left rear axle.

Rear axles: The left rear axle will have a freewheel mounted to its inner end as if it were the right side of a rear wheel. The right rear axle will also have a freewheel but it will be reversed so it will also tighten when driven. Mentally slide the one from the left axle across to the right axle and you'll see what I mean. How I will fix them in position is still a little open as the only things I want to weld to the axles is the wheel mounting flanges. That way, everything else can be disassembled. They aren't welded there yet because I intend to make thicker ones and replace the spacer discs with nuts on the wheel studs instead of having to weld them in place.

Free wheels also screw into the right hand cups of a BB shell ? maybe easier to find and weld than 2 wheel hubs ?

Hadn't thought of that. Subject to the finished length, that could be a possibility - now that I am a little way down the path to ruining some otherwise perfectly good wheels. I may be able to use that idea for mounting the freewheels to the rear axles. I can buy collars with grubscrews for $AU13.20 each but they would have to have machining and threading before I could use them.

On your rear wheels that will be removeable ? how do you intend to keep them snug against the drive flange and stop them coming loose?

A nut and spring washer on the end of the axles. I purchased a 5/8" die when I first started making my own hubs a few years ago.

Thanks for the encouragement.
 
Joined
Feb 7, 2008
Messages
2,719
Location
Nottinghamshire England
Rear axles: The left rear axle will have a freewheel mounted to its inner end as if it were the right side of a rear wheel. The right rear axle will also have a freewheel but it will be reversed so it will also tighten when driven. Mentally slide the one from the left axle across to the right axle and you'll see what I mean. How I will fix them in position is still a little open as the only things I want to weld to the axles is the wheel mounting flanges. That way, everything else can be disassembled. They aren't welded there yet because I intend to make thicker ones and replace the spacer discs with nuts on the wheel studs instead of having to weld them in place.
Going to be busy in there !

On your rear wheels that will be removeable ? how do you intend to keep them snug against the drive flange and stop them coming loose?

A nut and spring washer on the end of the axles. I purchased a 5/8" die when I first started making my own hubs a few years ago.
Think I would want something a bit more positive ? like a old style castellated nut and split pin ?

Thanks for the encouragement.
Your welcome , a path I may go down myself one day .....
 
Joined
Feb 20, 2013
Messages
789
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
Think I would want something a bit more positive ? like a old style castellated nut and split pin ?
I hadn't thought of a castellated nut at this stage. It should be quite easy to replace a standard nut with a castellated nut and a split pin through a hole drilled in the axle. I might just do that if the wheel falls off - if I get home to do it.

Thanks for the suggestion.
 
Joined
Feb 20, 2013
Messages
789
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
I retrieved a heap of rear wheels from the shed and managed to find two identical hubs and cassettes. Obviously they are used and probably should be replaced but the purpose here is to prove a workable process for separately driving delta rear wheels from a mid-drive with something of a cheap pseudo differential action. This is not necessarily required for normal riding but, if you want to be able to spin around on either rear wheel, separate wheel drive is. In any case, it is an interesting concept to explore.



The freehubs were removed from the wheels, followed by the hubs themselves. One of the cassettes was removed and a sprocket, closest to the size of a single freewheel, was the first to be fitted back on the carrier. This was the one required to drive the chain for the right rear axle and it was followed by a spacer and the largest of the sprockets in the set.



First problem: It would take two spacers to sufficiently separate the two sprockets that, when using the lowest gear, would both have a chain - one from the front and the other to the rear. The two chains would not clear each other. This was fixed by fitting another spacer.

Second problem: Using the second spacer interfered with fitting all the remaining gears. The cassette carrier was a stepped type and there was no room left for the last of the largest centre diameter sprockets to fit. That meant that I had dropped two gears. No problem long-term as a more modern rear hub with more gears and a non-stepped carrier would fix the problem.

The loss of two gears should not interfere with the mid drive operation with the proposed sliding gear selector. The purpose here is to prove the process. Anything can be refined later. Cosmetics aren't being considered here either.
 

SirJoey

Super Moderator
Joined
Feb 8, 2008
Messages
4,759
Location
My cozy little nook in the corner!
Those pics make me long for the days I had a monstrous pile of donor bikes,
& several piles of pre-sorted parts. Those were the days! (For ME, anyway) :rolleyes:
***
 
Joined
Feb 20, 2013
Messages
789
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
I have a shed that is difficult to get into, with bikes hanging from the ceiling, the walls, and other things standing on the earth floor. I didn't want to bend down and lift things with my back problem. Removing some rear wheels from the hanging bikes was an easy job and put them in a more accessible place for comparison. That pic is in the shed in which I am building.
 
Joined
Feb 20, 2013
Messages
789
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
The left side freehub was first fitted with the same size sprocket as the first one on the right side – for driving the left rear axle. The rest of the freehub was filled with spacers as none of the other sprockets were required.

The two hub halves were then placed end to end and then compared with the width of the main boom to decide the mid drive’s final width. This has impact on the inner ends of the rear axles as the longer the mid-drive, the further out from the centre the rear driving sprockets will be.

Two flange discs were cut to the diameter of the modified half-hub spoke flanges. After opening up their centres to clear the remaining hub centre tube, they were placed against the hub spoke flanges. Six spoke holes were drilled through each hub spoke flange and the discs for small small bolts that would hold them all together. After bolting them to their respective hub spoke flanges, they were tack-welded to a short section of tube, the whole forming a spacer to hold the modified hubs apart.



An axle was fitted to complete the mid-drive.
 
Joined
Feb 20, 2013
Messages
789
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
The specific construction of the mid-drive was for proof of concept for what I had in mind. Yes, it seems to have worked but I now have a small concern related to accessing the cones that are now “buried” deep inside both ends of the mid-drive, unlike with a standard rear hub where one end is usually visible. It may not be an issue. The cones do not have to be all that tight and are usually held in position with a lock nut. The lock nut could be little more than finger tight and, as the mid-drive will seldom be removed, more positive locking could be provided by the outer axle nuts.

Removal will require that what would have been the cone lock nut is first removed and that might mean that the cone and locknut will unscrew together, possibly with difficulty. If the nut is removed on its own, anything that stops the cone from turning – plastic tube, wooden wedge, a carefully squeezed thin-walled tube – could be used to hold the cone while the axle is unscrewed from it. Later freewheel removal may be an issue because there will be no attached wheel from which to provide the leverage to unscrew it. However, the centre of the mid-drive is considerably stronger than a thin-walled hub and can be used for clamping.

Further thinking on the outcome got me to thinking how I could make another mid-drive using a bottom bracket and modified chainrings on each end and a conventional cassette as well on the right end. The left hand end will be a cinch and making the right end turned out to be very easy but you will have to wait for another update.
 
Top