Mid Monster Test Bike

[ElectroSurf3r]

Hey yall,
This is my first solo ebike creation! I got a new scooter hub to test, dubbed "Mid Monster", and this thread will follow the build. The motor will be for sale on ES once we give it the green light.
I want to do a good bit of mods along the way, and I am trying to document my efforts, so we can all learn. Please chime in with any helpful knowledge!

So without further ado, Ladies and Gentlemen, the star of the show, and our test subject, Mid Monster!

Hello gorgeous wire bundle containing 6 phases! And shiny 10 inch scooter rim with tubeless valve!
WAIT. Why are some of the cover bolts missing?

View attachment 9
OH NO

A quick glance over at the box that wasn't inspected in all the excitement:

GRRRRR
They just HAD to open it, and then didn't even close it back properly!


I do not like that!


Or that!
NOT COOL, DHL! :x


...So after moping around for awhile, I decided to go to Harbor Freight and get a giant 8 inch 3-jaw gear puller for $17.
We've got to diagnose the patient.


...and...

View attachment 4
YES!!! the magnets appear to be fine! As do the laminations, halls, windings, etc. The debris in the gap must have just been small chunks of the cover that got pried off.
DHL is still LAME, but this baby appears to be healthy! Now let's see what we got here...

56mm stator width, 163mm stator diameter.


Very fine laminations!


A quick check reveals approximately 29 laminations per cm, giving a total around 162 laminations over the 56mm width.

The windings appear to be 12 strands of 20ga magnet wire, so better than 10ga overall!
I see 20 magnets (10 poles), 24 stator teeth.
20mm Axle
14mm flats
194mm between flats
161mm cover to cover width
198mm cover outside diameter

6 phase wires, 10 pin hall connector, 2 pin temperature connector. 2 controllers to run this puppy!

Let's compare it visually with Mini-Monster HE 2-speed, which is on sale right now for a great price: http://endless-sphere.com/forums/viewtopic.php?f=31&t=40859


Key differences for Mid Monster: 3 hole disc brake mount, larger motor diameter and width, shorter axle, 6 phase, 1 speed.


Now I am trying to decide between:
1.) putting it back together, testing it stock, and continuing the bike build -or-
2.) embarking on ventilation & waterproofing mods this weekend.

The only controller options I have are 70A 18fet, and I have always run 20s, 74V nominal.
With 2 controllers drawing 70A battery side each, the first test ride will easily be surpassing 10 kW. It needs ventilation asap...
Looks like friday's shopping list includes drill bits, center punch, sheet aluminum, small bolts, epoxy, high-temp motor paint, and BEER.

 

[John in CR]

For those who like the numbers, the factory tells us these are wound to the same Kv as the larger HubMonster HE that I'm testing, which is 16rpm/volt. I haven't been able to poke any holes in their claims so far, so I do have some confidence in their efficiency claims as well. At 57A from the battery the mid size produces 155Nm at 25rpm, and has a peak efficiency of 93% at 848rpm with 57V, so this puppy is really going to shine on the standard 20s (23s lifepo4) packs we run. These 6 phase motors are great motors both in design and function.

I can't wait for Jay to get some road testing done in-wheel with the Mid-Monster. Then I'll talk him into hacking the rim off and put it in the mid-drive design I've come up with. This one will prove much easier to implement than the MiniMonster with only a slight gain in weight and size....Just make a sprocket fit the brake disc mount, clamp the motor on the bike, and you're ready for a chain. Since the reduction would be less than 2:1 even for a large diameter bike wheel, it just doesn't get any easier.

John

 

[ebiker1]

i own an xb610 and have been looking for compatible integrated 16" motor/wheel replacement. mine is apart right now because one of the motor wires shorted out and i gotta fix it or buy a new motor/wheel. i'm guessing that the mid monster is for a real scooter, not an underpowered ebike w/ fairing. still, it would be nice if i could jam something like that into the bike. how long is the axle, or, how wide would the swing arm need to be? and hey, i know a few people think these types of bike are a joke but it worked right out of the box and it gets me to the store and back basically dry (seattle). so if i can find a bigger, badder motor for it, maybe i wouldn't be SO sensitive about it. oh yeah, and i've got an ebike, that isn't working, and a project mid drive bike that i'm working on. ps. - i'm newb to ES.

 

[John in CR]

i own an xb610 and have been looking for compatible integrated 16" motor/wheel replacement. mine is apart right now because one of the motor wires shorted out and i gotta fix it or buy a new motor/wheel. i'm guessing that the mid monster is for a real scooter, not an underpowered ebike w/ fairing. still, it would be nice if i could jam something like that into the bike. how long is the axle, or, how wide would the swing arm need to be? and hey, i know a few people think these types of bike are a joke but it worked right out of the box and it gets me to the store and back basically dry (seattle). so if i can find a bigger, badder motor for it, maybe i wouldn't be SO sensitive about it. oh yeah, and i've got an ebike, that isn't working, and a project mid drive bike that i'm working on. ps. - i'm newb to ES.

Hi Ebiker1,
Sorry I missed the post. Jay has been too busy with work and learning stateside to make any headway on testing the Mid-Monster. I just got my first one down here for testing on Tuesday, and will get it going as soon as possible. The pictures don't do it justice, because it's a beauty. To add to Jay's summary above:

The rim is alloy, not steel, and this powerhouse including the rim comes in at only 12kg.
The 6 phase wires each have a 3mm diameter, making them the metric equivalent of 10ga.

To answer your questions. I'm not familiar with the scooter you mentioned. Measure the outside diameter of the tire, which I take is approx 16"....scooter tires run sometimes like bicycle tires, quoting the size as the nominal OD and sometimes like moto/car tires that quote the rim size and the other numbers tell you width and height from there. The Mid-Monster has a 10" rim. Those tires range from almost 17" down to near 15" OD depending on the tire, so I think wheel size will work for you. This does have a 3 bolt disk brake mount that those pedal scoots don't. The width between the swingarm is 194mm between the flats. You will definitely have to beef up some stuff in there, but depending on your swingarm it could be your torque arms too. I did that with my daughter's emoped that started life as a 15kph POS and now is a useful vehicle that does almost 50kph.

She only weighs 105lbs so her's works for her. The Mid-Monster is plenty for a full size adult.

What kind of batts are you running and how much do you weigh? What kind of speed do you want and what kind of hills do you have?

John

edited to correct phase wire size based on actual measurement.

 

[ebiker1]

John,

no problemo, i'm just glad i got a reply! i just realized you said a 25% grade? that's unbelievable! i've got a hill going to town that is a 12% grade at the steepest(middle) part of the hill. and it's about 1.5 mi. to the top. in fact, i just bought a mid drive kit to do it. because--- i've lost my license till 2019. don't ask. anyway, my emoped only has 150mm in between the dropouts. it is steel though, so rework is feasible(i'm an out of work welder). at this point, though,financially i can't. saw your post and had to ask about it. way cool. got to looking at the wiring on mine and found the problem. phase wires need to be upgraded. i'm just going to replace a section of them for now. if i bought one of your motors then i'd have to buy a better controller. then i would have to get li-ion for it instead of my SLA and i just don't have the $ or time for it right now. my ebike needs new batteries first. and too many other things going on. thanks for getting back to me, though

 

[John in CR]

Update on construction. Now I understand why this one is so much lighter at just under 12kg on my bathroom scale...The rotor is all alloy. My magnet doesn't even stick to the beefy disc brake mount. That means the magnet backing ring is an insert. The rim is so pretty and neat that I don't think I can get myself to cut it off yet just to find the weight of the raw motor.

This makes ventilation mods to go to extreme power a snap...easy cleanup with no steel/iron sticking to the magnets, and no need to paint afterward.

Maybe I'm just a ebike geek power freak, but this just got really exciting for me.

John

 

[LI-ghtcycle]

Sounds great John!

You have any dimensions on the motor it's self minus the rim (for mid-drive purposes)?

I'm particularly interested in the over-all diameter of the motor case.

Thanks!

 

[ElectroSurf3r]

Hey y'all,
Sorry for going AWOL. I'm glad that Dad was here to clarify some things for ebiker1.
LI-ghtcycle, these numbers are from my first post above, and should answer your Q's :
194mm between flats
161mm cover to cover width
**198mm cover outside diameter**

 

[ElectroSurf3r]

It's alive!


I finally got around to putting this motor on a bike. I tested it in stock form, running 100 amps total, 50A per controller. 78V measured before test run. Sag to around 74V would give 7.4kW peak power.
Now I've ridden a number of different Ebikes, ranging from 4-16kW. I have to say this bike feels like at least 10kW when current limiting cuts off around 30mph
In a 10" scooter rim, and a big Pirelli that puts the OD at almost 19", it is a ton of fun. It's already put a couple virgin ebike grins on people here in Baton Rouge.
I believe this is a tribute to the efficiency of Mid-Monster. Greater efficiency means more power to the pavement for the same battery input, and also creates less heat!!!
I don't have a CA on hand, or a simple way of measuring peak current. When I do, I will post the exact data.

Now I know she's not perfect :wink:
This is a cheap steel full-suspension bike off eBay. I decided not to perform any motor modifications, since this bike is meant to be a test platform. I also decided against a mid drive, because I don't have the necessary tools at the moment. So I went with stock form, rear wheel hub. It has the original 26" front tire and rim brake right now. At least I got the regen braking working.
The swingarm had to be spread (we used a car jack), and dropouts had to be opened to 14mm, using an angle grinder. I wanted clamping dropouts, but didn't have the steel on hand to make it happen. So I took two 14mm open-ended wrenches, and attached them to the swingarm by drilling holes for 2 bolts in each. The dropouts face the opposite direction of the wrench opening, so they effectively pin the axle in and regen forces cant make the axle come out of the wrench slots.



It's a nifty way to get decent torque arms, if you don't have a welding machine on hand. But I would much prefer proper clamping dropouts.

When we finished the build, it was rainy and dark, but that didn't stop us from making a few test rides. I hit at least 40mph, and the bike had plenty more, but my nerves did not. 8) Tomorrow I'll see what she's really got. I have to figure out a way to get an accurate top speed for y'all.
I will say that we had 4 stop-and-go test rides (about 1.5 Ah), and nothing even got warm to the touch.
More pics and video coming later!

 

[hjns]

I am impressed. Looks awesome. 12kg is actually not that much more than my 10kg cromotor.

I do have some questions:

• Why only 50A per controller, as you said you have 70A controllers available?
• What controllers do you use (programmable?), and what FETs are in there?
• How do you keep both controllers in sync and how do you drive them with a single throttle?
• Do you have regen working on one or both controllers, and could you even choose to use one or both controllers for a kind of 2-stage variable regen?
• Will you attach a meter to the thermometer inside, so that we can see the motor's heating profile?
• I guess no rear gear for a pedal chain, right?

Last thing, I really fear for the dropouts. It looks like the axle is only held by a surface of 1 inch of steel (frame + wrenches) on (both?) sides, and that would make me extremely uncomfortable with the amount of torque that you have at hand.

 

[ElectroSurf3r]

Thanks hjns!
- My 70A controllers don't have regen. I opted to use the 50A controllers because I knew I was only going to have a front brake at first, and needed the regen capability.
- I am using two Greentime 15fet 4110's
- The controllers are naturally OUT OF SYNC, because the stator teeth alternate between controller 1 & controller 2. This results in smoother operation and battery power draw. Picture 2 motors on the same axle that fit together.
I just use one throttle that goes to both controller throttle plugs (all 3 wires)... it seems to work fine so far.
- At the moment I have regen working on only 1 controller. Yes, you can turn on regen in both controllers and have a variable-stage regen.
- I don't have anything that could log the temp reading, but it sounds like something I should look into.
- No pedaling for now

I appreciate the concern on the dropouts, because they definitely are not sufficient. Although there was no rocking in the dropout so far, I really need to make some proper clamps. But the bike also needs a longer swingarm, because it always wants to pick up the front tire. So I need to make a custom clamping swingarm happen, as well as get a proper tire and brake on the front.

 

[ElectroSurf3r]

 

[Whiplash]

That fattie tire looks cool! You need a matching front!!

 

[ElectroSurf3r]

Yeah it's a Pirelli 10" 130-90.
The front badly needs a 20" wheel with a hydraulic brake.

After riding it for a couple days, I have to say, I LOVE RIDING THIS THING!!! It's so unrefined in the front that it makes it more exciting. The adrenaline rush is insane. I haven't hit top speed yet, but have gone at least 50mph.

I've had 3 people besides myself ride the bike so far, all EV first-timers, all with different reactions:
-My buddy rolled back in with a deer-in-the-headlights look, then cracked the biggest grin ever.
-My uncle executes a controlled 10-ft wheelie, goes over to the gravel, spins a donut, then rockets down the driveway like an old pro. Rolls back in with an amazed look, saying "Brah, this thing is a TRIP!"
-My cousin cruises down the driveway, makes it onto the street, then wobbles and goes down! I run over, she's fine, bike is fine.

I am going to start taking video of first-time test riders and get the highlights and reactions. Also some onboard footage of the bike in action.

 

[John in CR]

Dang, I missed that you updated your thread. The bike looks a lot better than I had pictured it...well at least with no one aboard. My Wahoo looks fine with no one on it too, but with a rider the much smaller wheel looks silly. The fatty big diameter for a 10" looks cool. I see a 2wd Hanebirnk bype bike in my future.

Get some more batteries, and mod those shunts as equally as possible. The shunt is at the back end, so simple to mod without pulling the board as long as you watch the heat near caps or other components. Just pop the rear cover, weave some thin strand copper in a figure 8 over the 3 shunt legs, pack it down to one end as you go, and soak some solder in. About 1/4th to 1/3rd of the length should do the trick without going too far, while giving it a good kick in the saddle. I only did what looked like 1/3 of the length on my 18's and it went from 60A to 115A on one of them and to 95A on the other, so don't do half. 100A may be a bit much for those controllers, and we want to do incremental testing before trying 200A total on the MidMonster.

How's the sound of that motor? You didn't get to ride HubmonsterHE, but other motors sound like ICE's in comparison to true near silence.

 

[Hyena]

My cousin cruises down the driveway, makes it onto the street, then wobbles and goes down! I run over, she's fine, bike is fine.

Dude! The amount of metal holding that thing to your bike frame is atrocious! Get some serious reinforcements happening STAT, that's an accident waiting to happen especially at those power and speed levels. I'd be worried to ride it myself, let alone give it to noobs to test, and especially a girl. I dont mean to sound sexist but unless they've ridden motorbikes most are going to struggle, and the fact that she crashed after barely making it to the end of the driveway is proof enough.

Cool project though, just make it safer so you can enjoy it for longer with all your skin and teeth

 

[spinningmagnets]

I am going to start taking video of first-time test riders and get the highlights and reactions.

The Endless-Sphere bylaws state that just before a newbie takes off, you must ask them on camera: "You know this is dangerous, right?"

 

[John in CR]

I am going to start taking video of first-time test riders and get the highlights and reactions.

The Endless-Sphere bylaws state that just before a newbie takes off, you must ask them on camera: "You know this is dangerous, right?"

Only in California.

 

[ElectroSurf3r]

LOL

Dad- The motor is very quiet. Chip was complaining about not hearing the motor "at all" for throttle input. :lol: I told him you judge by the seat of your pants.
I definitely need to open those controllers... The bike needs some serious upgrades for safety, but those cost $, and a shunt mod essentially doesn't.

Hyena- You're absolutely right. I've instituted a 'no one rides it but me' policy, until it has some proper dropouts and brakes.

I really just need a new frame, but I can't find a cheap steel dual-susp with a 1&1/8 headtube to fit my Marzocchi fork. Right now, the bike is just a test platform for the motor and controllers... bare bones, quickly built, test rides only. Not meant for commuting or mixing with cars... I haven't left the neighborhood with it.

I will say that I haven't heard any rocking in the dropouts, and it has felt pretty solid on small bumps. But I can't get complacent! I need something safe to commute with. I have a Ninja 250 project bike, but that beast is getting 2 motors, 4 controllers.

 

[John in CR]

Chip, aka Captain Crunch for crashing my boat, has no idea how he get's to be spoiled right off the bat. He should have to ride a noisy kiddie ebike first like the vast majority of ESers. Just tell him the silence is so when he builds a fat tire Hanebrink-type ebike or HubmonsterHE powered ATV, anything with a decent set of antlers in the area won't know exactly where he is like they do every time he heads into the woods on any gas powered rattletrap.

Regarding your dropouts, you have a steel bike, so get a couple of 5/8" to 3/4" scraps of flat stock scraps from your buddy. Cut slots to fit the axle, and drill holes for clamping bolts. If your wheel is good an true now, just slide the new drops on the axle with the motor on the bike, tack them in place, and remove the motor for proper welding.

Hyena rides aluminum bikes, wears crash gear, and sells RC Lipo ebike packs to others, so take his dire safety warnings with a grain of salt. You've got a high Kv motor in an 18" wheel fed with only about 8kw peak, so that steel isn't going to just snap with no warning.

 

[ElectroSurf3r]

So there has been some excitement since my last post...

Ignoring Hyena's advice and my better judgement, I let a friend ride the bike. Now in my defense, he was the person who helped me build the bike, and had ridden it a number of times already, including some unauthorized off-road mud excursions. So if anyone deserved to ride, it was him.
Apparently one of the pedals was not seated all the way in the threads...? So when my buddy went off a curb, standing to cushion the bump, the pedal broke off. This started a chain reaction that ended with both my bike and buddy on the ground. He was fine, just some minor scrapes and a bruised ego. The bike sustained more serious injuries, but nothing that wasn't fixable.

After some time in the operating room, I finally got the wheel spinning again. Airing the tubeless tire back up turned out to be the biggest challenge because the tire did not want to sit back on the rim, and was just passing the air out. I had to put a ratchet strap around the perimeter of the tire and squeeze it in, which bulged out the sides enough when I started to fill it up again. Soapy water also helped. Taking the strap off made a scary BANG , but the seal held and then I was able to fully air it up. I am not sure why I didn't run into this before, but the lesson has been learned!

So as of now, I have the right combos but I need some ring connectors for the phases to test a group of new 24fet, 80A controllers I got.
I'll be getting the connectors tomorrow, and should be riding the bike Friday morning with the original 50A controllers. When my new LiPo's come in next week, I can add them in parallel, and be able to handle the 24fet controllers giving me 160A total, around 12kW.

 

[999zip999]

Why can't you have the vidieo of the next test flight please.

 

[Science Faction]

Update Please!

 

[Teh Stork]

Airing the tubeless tire back up turned out to be the biggest challenge because the tire did not want to sit back on the rim, and was just passing the air out. I had to put a ratchet strap around the perimeter of the tire and squeeze it in, which bulged out the sides enough when I started to fill it up again. Soapy water also helped. Taking the strap off made a scary BANG , but the seal held and then I was able to fully air it up. I am not sure why I didn't run into this before, but the lesson has been learned!

Screw the "inner valve" of your air vent all the way out when you are seating the tire to the rim. Afterwards insert the inner valve and fill to the normal pressure.

 

[wrekinwanderer]

Hi ElectroSurf3r,

Love the bike! I'm considering replicating your build. I'm wondering what size wheel rim takes the

Pirelli 10" 130-90

? Does the mid monster lace into a standard rim? How's it going at the moment? Also is there anything you would do differently next time?

Mike