Hubzilla Cromotor V2 information

zombiess

10 MW
Joined
Jan 31, 2011
Messages
3,048
Location
Oklahoma City
I want to use this thread to post up information on these motors in one location for others to reference if they are using them.

First the most important, the phase / hall wiring combinations
If you are using a Lyen Controller on one that uses the same color combinations as his the wiring is as follows (same as original version)
Phase:
Motor -> Controller
B->B
G->G
Y->Y

Hall connector 1:
Motor -> Controller
R->R
B->B
B->B
G->G
Y->Y

Hall connector 2:
Motor -> Controller
Orange -> Red
Black -> Black
Grey -> Yellow
Brown -> Green
White -> Blue

kV measured the same as the previous version 9.3kV
Inductance appears to be slightly higher than the previous version and measured it at 145uH vs the previous versions 120uH

Axles are 16x1.5mm thread pitch
Continuous power handling is rated at 5000W, I have not tried to torture test one yet, however my original version survived lots of abuse at 12,000W and still looks new on the inside and the covers are sealed.

Will it FIT! without lube or stretching :mrgreen:

The axles on the V2 are different from the V1
The flange of the V2 motor is centered, not off center like the V1 is (but corrected for with a custom axle to center it). The axle ends are 40mm long from the shoulder and have 40mm of thread. This means that the V2 Axle is 40mm+137mm+40mm for a total of 217mm long with the 137mm shoulder to shoulder portion centered along with the flange.

That's always the question with something packing this much awesome so here are some measurements I've made with pictures to hopefully help you figure out if it will fit on your frame.

I made on my makeshift test stand that has a dropout width of 149mm.

First up, 2 shots of my testing setup
01dropoutmeasurement1.jpg
Close up
02dropoutmeasurement2.jpg
Freewheel side placed against the drop out, there is some small variance in where the axles shoulder flat is between motors, about +- 1mm judging from what I've seen.
03freewheelsideagainstdropout.jpg
Wire exit and disc brake side. These are of course all sans disc brake so please take into account it's size and the bolts that hold it on when trying to figure out if it will fit.
04wiresidespace.jpg
Measured gap from axle shoulder flat to the dropout
05wiresidespace12mm.jpg
This is the reason I supply the freewheel side washer with the motors. It's not always needed, but differences in freewheels and small variances in the axle position necessitate it. This is a random 16th Dicta brand freewheel I happened to have laying around with the washer in place. I did not tighten the freewheel at all, so it can go down further than pictured here. This motor has the axle shoulder perfectly flush with the freewheel threads.
06freewheelwithwasher.jpg
Washer thickness used for demonstration.
07freewheelwasherthickness.jpg

So what is the theoretical minimum dropout size that we can fit one of these motors into?
Dropout distance of 149mm - disc brake side gap of 12mm = axle shoulder to shoulder width of 137mm. I believe the actual spec is 135mm they are machined to, so the difference is just measurement error, but I'll err to the side of being bigger at 137mm.

Add to this the freewheel + washer most likely needed to prevent binding and you end up at 140mm (a thinner washer could be utilized in many cases, I went with a size that I knew would work for all variances that I have encountered in axle offset to prevent binding).

So if you were to run this without a disc brake, you could theoretically run this in a drop out as small as 140mm, but I can't guarantee that due to variances in frame design and small differences between motors. This is why the official spec is 145mm minimum with work, but it can be made to fit smaller dropouts if you have some skill/creativity.

Next up, how to take your motor cover off and add a temperature sensor.


I'll add more info as I gather it.
 
Accountant said:
Axles are 18x1.5mm thread pitch


NO,NO,

Correct information =

Axles are 16x1.5mm thread pitch


Big THX, for the other ifnos.

I made a typo, thanks for catching it. I've corrected the info.
 
Hi Guys,

I just discover this post I just received my motor and it came without axel nuts, then any 16 X 1.5 nuts will fit :?:

On the break side of the motor I have some sort of metal spacer; can I remove this spacer and fit my disc break on the cover instead :?:

Thank you!
Black Arrow
 
Take the spacer off,put it on your disk,and drill new holes. Then you can attach the disk to the hub. But be warned that their still won't be room for the caliper. Now its time to think about 10 or 12" saw blades as a rotor if you have room. Or just settle for regen braking. I would like to know what others come up with.
 
BlackArrow said:
Hi Guys,

I just discover this post I just received my motor and it came without axel nuts, then any 16 X 1.5 nuts will fit :?:

On the break side of the motor I have some sort of metal spacer; can I remove this spacer and fit my disc break on the cover instead :?:

Thank you!
Black Arrow

I sent you a PM about the nuts since I believe you ordered from me.

That metal spacer is needed for the proper spacing of the disc brake. I run a 203mm disc to get enough clearance for a caliper due to the taper of the cover and I can lock up the rear wheel at 50+ MPH. I don't believe any larger rear brake is required. I also find my setup has pretty strong regen, but it is in a 20" diameter tire.

Why do you want to mount it directly to the cover without the adapter/spacer?
 
I'm also having the same disc brake rotor dilemma. There doesn't seem to be any spacer to give room between the 200mm rotor and the inside of the dropout. The only spacer that I got with the motor was one 16mm plain washer.

As it is, the screw heads for mounting the rotor will rub on the inside of the dropout. I really can't put washers in there to make space because any washer would interfere with the wires, unless the washers were cut out for the wires. I'm tempted to drill new holes in the rotor and do away with the adapter piece as mentioned above. It seems to me like the motor shaft should be longer to allow more space between the dropout and the rotor mounting surface. Either that or the adapter piece is just made too thick.

Anybody have any pictures of how they mounted things?
 
Rottenbind said:
I'm also having the same disc brake rotor dilemma. There doesn't seem to be any spacer to give room between the 200mm rotor and the inside of the dropout. The only spacer that I got with the motor was one 16mm plain washer.

As it is, the screw heads for mounting the rotor will rub on the inside of the dropout. I really can't put washers in there to make space because any washer would interfere with the wires, unless the washers were cut out for the wires. I'm tempted to drill new holes in the rotor and do away with the adapter piece as mentioned above. It seems to me like the motor shaft should be longer to allow more space between the dropout and the rotor mounting surface. Either that or the adapter piece is just made too thick.

Anybody have any pictures of how they mounted things?

Do you have a picture describing what you are referring to? I suck at doing mechanical work but managed to get everything to clear OK on my setup. To space the drop out I just used a C washer to make everything clear. On the inside of the disc rotor near the wires I ground off the inside tips of the disc rotor.
 
What diameter should threads be on freewheel?
From what I'm reeding dicta 14t is pretty much as good as it gets.... Any other suggestions?
 
zombiess said:
Do you have a picture describing what you are referring to? I suck at doing mechanical work but managed to get everything to clear OK on my setup. To space the drop out I just used a C washer to make everything clear. On the inside of the disc rotor near the wires I ground off the inside tips of the disc rotor.
Hi Zombiess

The only C washers that I have in hand are 14mm, the Axel on the V2 motor is 16 mm then none of them fits. I don't know why these C washers are not supplied when we bought this motor like Chrystalite motor for instance. Otherwise I think this new motor is really well made and can dissipate heat much better then the previous version.

I will do a C washer from 16 mm washers because it's the only way to have the proper clearance for my disc brake on my ebike, is my quick fix for this issue.

Good day!
Black Arrow
 
They are not supplied because nobody makes them. In my case I used 14 mm c washers and cut an end so they fit. I am getting quotes to make up the needed washers this week. The motors come without any hardware. I add the nuts and freewheel washer to help out, but those are common parts. I have to get the c washers custom made. I already have a design.
 
I finally did get things sorted out. I think that I ran into more problems because I installed the Cromotor onto a frame with a 135mm dropout spacing. I had to bend the frame apart a bit to get the motor to fit and I didn't want to go wider still in order to fit some fat c washers.

I ended up removing the rotor adapter and making new holes in the rotor so that it could be bolted to the motor housing. I had to use a couple of washers under the rotor to get enough spacing to clear my BB7 caliper. I also had to use a couple of c washers between the motor and the dropout anyway, just to center up the wheel. Even with these washers, there would not have been room to use the supplied rotor adapter. Then I had to make a custom caliper mount so that the caliper was spaced properly and also so that it didn't interfere with the rear rack that holds my batteries.

The build didn't really go that bad, even with a 135mm wide frame. It was just a bit tricky getting the brake caliper mounted and aligned correctly. It's a great motor and I'm glad I got one!
 
Rottenbind said:
I finally did get things sorted out. I think that I ran into more problems because I installed the Cromotor onto a frame with a 135mm dropout spacing. I had to bend the frame apart a bit to get the motor to fit and I didn't want to go wider still in order to fit some fat c washers.

I ended up removing the rotor adapter and making new holes in the rotor so that it could be bolted to the motor housing. I had to use a couple of washers under the rotor to get enough spacing to clear my BB7 caliper. I also had to use a couple of c washers between the motor and the dropout anyway, just to center up the wheel. Even with these washers, there would not have been room to use the supplied rotor adapter. Then I had to make a custom caliper mount so that the caliper was spaced properly and also so that it didn't interfere with the rear rack that holds my batteries.

The build didn't really go that bad, even with a 135mm wide frame. It was just a bit tricky getting the brake caliper mounted and aligned correctly. It's a great motor and I'm glad I got one!

Sounds similar to some of the issues I ran into myself when I got my first motor from the very first batch ever sold by Greyborg. One of the issues with motors and bikes is there is a very wide variation in rear drop outs and construction and no one solution works with everything.

Glad you got it up and running.
 
203mm rotor, adapted straight on the motor cover. No spacer, Magura Gustav caliper clears the motor fine.


dsc03414kh.jpg
 
I just installed a K type thermocouple for my 4 channel data logger (process would be about the same for any kind of temp sensor you wish to use) into my motor tonight and documented the process with pictures. I will post them tomorrow. It's pretty easy and even with doing the photography only took about 1.5 hrs. It can be done much faster than that though.
 
How to add a temperature sensor, with pictures.

Word of warning, opening up your motor will void your warranty, but since most people purchase these with the sole intention of voiding the warranty, here is how to do it. Make sure your working surface is clean and free of any magnetic debris. You do not want to get anything inside the motor and the magnets are quite strong. You also should mark your covers to where they fit on the magnet ring so that it can be reinstalled back into it's original orientation. It is possible that the bearing will stick on the shaft and not come off with the cover. This may or may not present a problem for you. If it sticks and you need to remove it, you must do so in a way that does not damage the bearing seals.

It is also good practice to place a nut on the opposite side of the axle (the one on the bottom) as I shown here to protect the threads.

The wire side cover needs to be removed
02wireside.jpg

It is accomplished with two tools. A 4mm hex wrench and a large gear puller. I purchased a set of 4 gear pullers from Harbor Freight for $25. They sell the largest 8" one in the set by itself for $16
03hexwrench4mm.jpg

Make sure to remove all perimeter bolts, the disc brake adapter does not need to be removed.
05boltsremoved.jpg

This is the type of gear puller to use
06gearpuller8in.jpg

This is how the gear puller is setup. You should ensure that the 3 hooks are firmly below the lip of the cover before using a wrench. It is best to start tightening it by hand to get everything snug. You want the jaws to be placed between the holes as well. The center of it needs to be positioned in to the dimple.
07gearpullersetup.jpg

Using a ratchet, start to turn the puller. The cover will start to come off easily. If it is not coming off easy or is hanging during the process STOP! Check to make sure everything is correct such as all the bolts being removed.
09gearpullersetup.jpg

The Cover will start to slide up the axle shaft, it should do so evenly.
10gearpullersetup.jpg

The cover is now removed exposing the internals.
11coverremoved.jpg

Here at the top are the hall sensors
12hallsensors.jpg
It's hard to see here, but at the left is the temperature probe I am using. I chose to install a K type thermocouple because I use a 4 channel data logger to monitor controller FET temps for testing and have several of these and a very nice meter. They are also easy to interface into micro controller projects.
13tempprobe.jpg

14tempprobe.jpg

You will need some sort of stiff pole/wire to run through the sleeve of wiring to run your temp sensor wires. I used a coat hanger, but it was shorter than the length of the sleeving so I pulled it down to make it shorter.
15sleeve.jpg

My make shift fish tape. I cut off the ends which would snag and straightened it out nicely
16hanger.jpg

This shows both ends of the coat hanger fish line already strung through the sleeving. It is easiest to straighten out the wire when running your fish tape/coat hanger through to make sure it does not pierce the sleeving. I curved mine back for photographic purposes, your line should be straight.

At this point you want to attach your temp sensor or wire to the line with tape so that it may easily be pulled through. I used masking tape for easy removal. The direction you run the wire in depends entirely on how your temp sensor is setup. It might be easier to go motor to outside or outside to motor.
17fishline.jpg

This is the probe installed. I changed the heat shrink around it for a tighter fit. It's not pictured here, but I looped it around the big internal zip tie to act as a strain relief if it gets pulled on.
18probeinstalled.jpg

You can just barely see the tip of the sensor protruding from underneath the coil touching the one next to it.
19probeinstalled.jpg

Now it's time to re-install the cover. The sleeving can be pulled down as pictured here to help protect the wiring a little more, but it makes installation of the cover much harder. I suggest installing it like normal with all of the sleeving just outside of the motor.
View attachment 3

Once you have the bearing started on the shaft it only takes a small amount of pressure and wiggling to seat the cover back onto the motor.
21coverinstall.jpg

To install the covers loosely thread all of the bolts back into the holes after pressing the cover on by hand. Then start to slowly tighten each bolt a little at a time using the following pattern. Do them in several steps to keep the cover even. You can monitor your progress by looking at the side of the cover and seeing how much gap is left between it and the magnet ring. DO NOT OVER TIGHTEN THE BOLTS! They just need to be snugged.
22coverinstall.jpg
23coverinstall.jpg

After final assembly you need to rotate the wheel/shaft by hand to feel for any points where it might bind. It should move very smoothly from any position. If it does not, you most likely don't have the cover properly torqued and the stator is rubbing the magnets.
 
After pressing out many of these motors I have found an additional step that members should take to assure positive results. Although the axle is captured in the Stator - it is still possible that it will not "settle" into the covers. The covers can flex anywhere up to a few mm.... So it is recommended that you inspect your motor before disassembly to have a reference point.

We slide a PCB board along the interface between the axle shoulder and cover face. Typically (and this all depends on the motor - some are very different) the shoulder is about a PCB width out from the the hub cover on both sides.

Now... lets say you follow the above directions, press your hub apart, then press it back together. It is highly likely that your axle will not be sitting in the same spot! Due to all sorts of frictions... this can happen. What we do is flip the motor around and apply pressure one more time. With only an eighth turn or quarter turn you will hear a "POP" and things will settle into their original locations.

We also grease the interfaces that have to be pressed back together - as well as the tip of the axle where the press will grind and the threads of the press.

A good warning - many of these gear pullers are capable of cracking your covers... so if things are not going together well just back off of it, take it back apart, put the stator in the freezer, put the covers in the oven, get some room, and then you can probably just press them together with your hands.

While on this subject - members should be ware that there is a dozen variants of this motor... some axles sit deep inside the freewheel threads with a nice shoulder on the wire exit side. Some sit with the axle shoulder well proud of the axle threads. If your motor is one that has the axle shoulder sitting inside the freewheel threads then you need to use an Inside Washer or two to make sure your freewheel threads dont rub into your frame.

MORE IMPORTANTLY - if your axle sits proud of the freewheel threads then you need to be very careful on the other side. Where the wires exit.... if you just throw a washer or torque arm on there you can easily pinch the wiring to the point where it will rub on the cover and fail. Most folks are solving this by setting the motor in the drops such that the cable exits at the opening of the drop - then putting the torque arm on the outside. Another fix for this is running a C washer.

Personally - I don't like C washers. After time (if they are not made of the highest grade steel) I have seen them slowly open up and fail. The correct way to address the problem would be for the axle to extend out far enough on the wire exit side to protect the wires by allowing for a washer to be inserted that does not pinch the cabling. If that is too wide for a customers bike... and they dont want to widen the drops... then it is probably not the right bike to start with for a motor as big and powerful as this. I personally have always just jacked open my drops (aluminum or steel) - but then I am not running a walmart frame - I would only put a motor like this on a gnarly downhill frame that was built to take extreme abuse.

-methods
 
What are your thoughts about changing the Cromotor v2 bearings to ceramic versions? If it is worth it? If so what size are the bearings? I can try finding a good price for them I will post my finds. I did the front hub already for about $40
 
I am thinking about adding a temp sensor to my cromotor and have a few questions

In the pictures it looks like the temp sensor is just stuffed in there and not held down by anything. Do I need to glue or zip tie it down?

Also while I have the motor open should I go ahead and upgrade the phase wires? If so what type of wire should I use? I have 10 and 8 AWG hobbyking silicon wire but I can buy different type of wire if needed.
 
zombiess said:
Once you have the bearing started on the shaft it only takes a small amount of pressure and wiggling to seat the cover back onto the motor.

I have the bearing started on the shaft. It gets stuck after the bearing gets started on the final lip. I have wigged it and applied pressure by had and I can not get the cover back down.

EDIT:

I had forgotten about what methods said. I tried just heating up the cover in the oven but it did still not work so now the motor is in the freezer, It just barely fits.

UPDATE: I left it in the freezer for a few hours and the cover would still not go on. Maybe it needs to stay in the freezer overnight? well I tried to pull the cover off but the bearing stuck to the axle again (It did the first time I took the cover off the motor).

I have spent my whole day trying to get this cover back on...
 
Done a few covers recently. Bearing removal is easy with a 3 jaw puller. Reinstalling the bearing can be done with an object like a socket and pounded it on with a mallet, takes about 1 min to install and 5 mins to 3 days to find the right install object lol. The other way I have done it is pounding on the cover with a rubber mallet after getting it started by hand. Took me 20 mins start to finish on my last one. Beat the snot out of the cover, no damage. Used the screws to get it on the rest of the way. Pretty easy, but I have done around a dozen motor cover installs on various motors.
 
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