Super Stealthy Puma KMX

[deecanio]

Hi Jozzer,

yeh i am also aware of the motors limits and mean to push it just to that and no more
like you im a massive puma fan, the way it pulls me uphill in the forest is amazing so im reluctant to use a 4 series instead.
The thermal cut out is a great idea and something knoxie advised, along with some mechanical changes too to be really sure everything will hold up, so if you do manage it let us know.
im going to try and run 50v @35a and hopefully that'll be ok.
it's a cert that a better puma is on it's way Lowell just not sure when.


cheers

D

 

[Jozzer]

We can only hope.
Same for a x5type puma, it would be great to have a 4KW motor that weighed like 6KG or so. I asked Mark last time I was on the phone, they dont seem to have plans to try it, and plans to improve the motor powerwise seemed to be last on thier mind, I think they are just trying to get a reliable midpowered unit at the moment, so that they can order in bulk and be sure of what they are getting!
THe advantage of a geared motor is plain to see, unless they have alot of extra reliability issues because of the gears then I would assume more manufacturers will produce geared motors of varying power/speed.

Mechanically wise, the axle needs beefing (it needs a "shoulder" like the x'lyte has in order to withstand more torque), also the power wires coming out the side are asking for it. As soon as a bike falls over to the right, it cuts the cable off at the axle. Both issues that x'lyte has had time to sort out...lets hope the puma gets there too!

 

[gwsaltspring]

Hi Jozzer;

You seem to have figured out the safe but exciting parameters for the Puma. Are the details documented anywhere?

IE something like 60V max, X-lyte 40A 72V controller with X fets mod. etc....

Seems that the specs are being worked out for the rest of us who are less adventursome. I for one appreciate your effort and the sharing of the results.

 

[deecanio]

Hi Greg,

like you i am dependant on guys like knoxie and rhubarb and jozzer who really are the pioneers with the puma, they all agree that there are limits to what you can feed in and as jozzer sais there is an issue with using xlyte controllers with them.
Knoxie is back and currently looking at three versions of puma and a factory controller so we will have a better idea once he has had time to test them all properly.
As things stand i think jozzer and rhubarb are at the limit of what this iteration of the puma can do.

cheers

D

 

[Jozzer]

Lol...you mean we will take one for the team and kill motors to find out how fast they will go :lol:

I would say that safe limits are 48v with an unmodified controller, though I dont really recomend you run the puma without changing the fets.
60v at no more than 35A for the sake of the motor. Highr voltages mean you must turn down amps, aim for around 1600w maybe max.
The motor WILL handle more for short periods, but overheats suddenly when loaded for too long, and can easily catch you by surprise. Sorry Gwaltspring, I didnt really have a thread going whilst building/testing.

I hope the controller Knoxie is testing cuts the mustard, it might solve a few problems!

 

[deecanio]

lol,yeh thats exactly what i mean!!!
we will see what paul sais about the controller, i'm hoping as it's specifically made for the puma it may help us all out
eventually we'll all be running at 50mph+


cheers

D

 

[rhubarb]

Took it out for a good caning today, pleased to say no probs so far.

Previous version at 56V blew about 4 standard 48V controllers before I built a reliably upgraded controller with 4110's.

Personally, I wouldn't bother running a puma above 48V without upgrading the controller. They will die and you will be traumatized, particularly if you didn't have the pedals and chain fitted and you have to push it 3km home

(btw, if you aussies out there are looking for 4110's, I have a supply, drop me a line and I'll send you some.)

 

[rhubarb]

Here's a few pix of how I did the battery baggy...

First a used tape to work out a viable orientation for my three lithiums.
Something to watch for it the lowest battery contacting the chain freewheel.

Note the controller is mounted just underneath the front of the seat where it gets airflow but is invisible.

Motor phase and sensor wires run up the RHS of the seat.

 

[rhubarb]

Once I knew where things would go I made some rough measurements and cut a piece of neoprene about 380x650mm. I put two holes in the lower corners and used a piece of string between these holes to pull the two bottom corners together while I sewed it up.

The seam was done with strong embroidery thread and a big needle stolen from my better half.

If I was doing it again I'd use a wider section and the join at the top of the seat would be neater and stronger.

There's a wooden block below the seat (held on with two blue cable ties and covered with black tape) which prevents the lower battery from pushing forwards on the chain idler which you can see just below it in the photo.

 

[rhubarb]

The batteries are simply placed inside the bag, and sit nicely as intended.

I've put some foam between them because they've got wide seams in the casing, it also prevents the wires on the bottom battery getting chafed.

Everything plugs together using yellow spade connectors which I've had no problems with. (tip- buy a really good crimper and wire stripper! Life will be much more pleasant). All the wiring is on the RHS, under the flap.

A downside of this design is that the seat has to be unstrapped to plug in the chargers- each battery pack has it's own charger.

 

[rhubarb]

forgot to say "please note the cool headlight switch mounted inside the LH handlebar"

 

[rhubarb]

Once the seat cover is strapped back on all you see is a slightly fat seat. The neoprene stretches when you sit in it so you don't feel the batteries at all.

 

[rhubarb]

Just a couple more pics. Lights are made from a 40/32mm plumbing adaptor with 28V globes from a marine supply place. Taped up for cool blackness and attached to a piece of flat bar with hoseclamps. Globes are 10W at 28V, but overvolted to 42V without drama to produce 22.5W or so each.

 

[rhubarb]

One more...

 

[rhubarb]

Oops- pic didn't attach.

 

[rhubarb]

finally got round to putting some vid on youtube...

http://www.youtube.com/watch?v=oK4FOv4FD1Q

 

[Drunkskunk]

Oh now, thats just Sick madness.
Stealth is the way to go!

 

[Jozzer]

Hehe, nice spill at the end These things are great for "drifting" corners arn't they?