Voltron, the Electric RG!

Post up a thread for your EV. Progress pics, description and assorted alliteration
User avatar
EV2Go
Senior Member
Posts: 2059
Joined: Wed, 16 Jul 2008, 00:21
Real Name: Paul
Location: Brisbane 1963

Voltron, the Electric RG!

Post by EV2Go » Tue, 03 May 2011, 01:01

Ok now you have really got my brain going.... are these other guys running the drive sprocket between the two motors like you? Remember the chain joins the motor to the rear wheel and the rear wheel touches the ground...

So when you accelerate from a standing start the torque of the motor has to twist that front sprocket which in turn transmits the torque to the chain, which in turn transmits it to the rear sprocket, which in turn transmits it to the wheel / tyre, which in turn transmits it to the ground.

Now... the ground says hey I don’t feel like being moved today and pushes back on the system that sent the torque, this in turn creates a load on the motor shaft, causing a pulling effect on the front sprocket trying to pull it closer (actually it's the front sprocket trying to "walk" backwards on the chain) to the back wheel (if Mohamed won’t come to the mountain...).

Guess what probably caused your shaft to pull out...
Last edited by EV2Go on Mon, 02 May 2011, 15:08, edited 1 time in total.

User avatar
jonescg
Senior Member
Posts: 3046
Joined: Thu, 21 Jan 2010, 23:05
Real Name: Chris Jones
Location: Perth, WA.

Voltron, the Electric RG!

Post by jonescg » Tue, 03 May 2011, 04:49

You just described in intricate detail the beginnings of a wheelie Image

Yep, the other guys are doing exactly what I have proposed, except they have a far more solid setup than my failed effort here.

This is what the shaft looks like:
Image

So these are my new plans for a replacement:
Image

As soon as I get a new motor shaft...
AEVA National Secretary, WA branch chair.

User avatar
EV2Go
Senior Member
Posts: 2059
Joined: Wed, 16 Jul 2008, 00:21
Real Name: Paul
Location: Brisbane 1963

Voltron, the Electric RG!

Post by EV2Go » Tue, 03 May 2011, 21:43

I continued thinking about this last night and wondered if maybe you could do something like this to make it more "pull proof"

motor on left, motor shaft coming from left, drive gear with double chain coupler, a centre bearing mounted back to the frame, double chain coupler, shaft from right motor, right motor...

Here's the thinking with a double chain coupler either side of the centre bearing it will extend the life of the centre bearing while giving you the slight angular flex you need for motor torque, but at the same time the centre bearing stops any radical movement of the shaft off axis.

You might get away with an angular centre bearing like this
Image
but what you need to bare in mind is what happens on one side would cause the opposite to happen on the other side, by putting flexable points either side of a non angular bearing (regular sealed roller bearing) each side would act independantly.
Last edited by EV2Go on Tue, 03 May 2011, 11:45, edited 1 time in total.

polo-ev
Groupie
Posts: 42
Joined: Tue, 20 Oct 2009, 01:12
Real Name: Ian Bartie
Location: Port Macquarie

Voltron, the Electric RG!

Post by polo-ev » Sun, 08 May 2011, 00:40

If you are going to use a solid shaft between the two motors, you will need to accurately machine the fabricated motor mount so both motors are absolutely dead in line, both axially & radially.
No matter how good the welder is or how tight the jigs are, ALL metal moves & shrinks when it is welded.
I have seen this many, many times after 20+ years in the metal fabrication/engineering game.
Your only other solution is to use two of any number of flexible type couplings. One at each end between the motors & the center shaft.
The centre shaft must then also be supported in its own set of bearings. These bearings will take all the radial load imposed on the shaft by the drive chain.
The shaft must also be strong enough to resist the bending moment imposes on it. This will depend on the diameter of the shaft, what it is made of, where the drive sprocket is on the shaft & the distance between to bearings.
Most of the flexible type couplings are designed to take axial load only. The challenge there will be to find a coupling that will cope with the torque of an electric motor as well as the maximum rpm.
The Lovejoy type you refer to usually have a cast iron carrier & are severely prm limited.
If it were me I would be machining the motor mounts to ensure motor alignment. I would also be using a solid shaft but final machine the shaft after any welding so that it runs absolutely true & runs in balance.
From the pictures, I don't think your motor mount arrangement is stiff enough. It is aluminium & aluminium is not that stiff or strong. Any radial load on the shaft is going to try & flex the shaft & pull the front of the motors together causing more flex in the shaft pulling the motors in more causing more flex etc etc.
The moutor mount assembly as it is can easily twist & flex. This is a no-no when you are trying to align 2 powerful motors & keep them in alignment when under load.
I reckon you need 1 or 2 chunky struts welded in the front area of your motor mount to stop the front edges coming in.
Weld some more diagonal or triangular braces in too to make it really stiff.
A lot of metal was cut out of the end plates. It would have been better if they were solid.
Then machine the whole lot so the motors are dead in line.
The connecting shaft should be long enough to almost touch the bearings on the motor shafts & the keys & keyways should be full length too.
If you don't do this you will get vibration, shaft fatigue, breakages, etc.
Not very good if the shaft is rotating at a high rpm under a reasonable load & you are lying over the top of it.

User avatar
jonescg
Senior Member
Posts: 3046
Joined: Thu, 21 Jan 2010, 23:05
Real Name: Chris Jones
Location: Perth, WA.

Voltron, the Electric RG!

Post by jonescg » Sun, 08 May 2011, 02:53

Yes, I agree on all points. The solid shaft is the only option I have for this bike, as it is too late to change anything substantially now. Centre bearings would be the only way to improve this setup, but the motor shafts are simply too short and the single load-bearing bush is no good for high load applications.

The plates were laser cut and welded on a precision jig, so they are as close to aligned as I can feasibly get. Despite the shaft failure at ~85 km/h the plates are still as aligned as they were when I first installed them - the steel keyways failed, not the ally.

I can't put any more support to the front as the battery packs actually reside between the two motor plates. I could possibly get more supports welded in the corners towards the back though. And the laser cut plates could be repeated with less metal missing, but again, timing.

I believe that my arrangement will be fine for the 4 or 5 races I will be entering into. Sure, the bearings will suffer from the rubbing at high RPM, but it will probably become a commuter after the season. This bike was always going to be a prototype, and the next bike (wife permitting) won't use Agnis again. Too much trouble.

I have my new 38 mm shaft ready for turning, just have to pop the bent motor shaft out Image
AEVA National Secretary, WA branch chair.

User avatar
jonescg
Senior Member
Posts: 3046
Joined: Thu, 21 Jan 2010, 23:05
Real Name: Chris Jones
Location: Perth, WA.

Voltron, the Electric RG!

Post by jonescg » Fri, 17 Jun 2011, 04:47

OK so the replacement joining shaft is here! I was going to start putting it all together but I ran out of daylight (winter solstice and all). But I tapped it in and it fits nicely. If there is any mis-alignment it will be a poofteenth of a bee's dick so I'm not too concerned. It's no problem to shim the spacers either.

Image
Image

So this weekend it all comes together! I hope to get my fuse box tomorrow, but I got a feeling it will be the last thing I wire up.

Big thanks to everyone who has donated to my race fund Image Image I'm at $187 so far, so that's already got my crated bike one third of the way across the country!

Nearly there!
AEVA National Secretary, WA branch chair.

soyachips
Groupie
Posts: 177
Joined: Mon, 04 Aug 2008, 05:44
Real Name: Andrew Lo
Location: Sydney

Voltron, the Electric RG!

Post by soyachips » Fri, 17 Jun 2011, 08:03

Hi Chris,

Great project!!! Regarding the bent motor shaft, I saw in a video about similar motors (LEMCO) that you can put whatever shaft you want in them when ordering so you might be able to replace the shaft instead of get a whole new motor. Pulling the motor apart requires special jigs though so would probably have to send it back to the factory.

http://www.youtube.com/watch?v=xbVTqkE_F1U

Good luck!
Andrew

User avatar
jonescg
Senior Member
Posts: 3046
Joined: Thu, 21 Jan 2010, 23:05
Real Name: Chris Jones
Location: Perth, WA.

Voltron, the Electric RG!

Post by jonescg » Fri, 17 Jun 2011, 17:32

Way ahead of you mate Image Agni Motors kindly sent me three replacement shafts and it was a half-hour job to get the bent one out and the straight one in. The special jig was easy to make myself.
AEVA National Secretary, WA branch chair.

User avatar
EV2Go
Senior Member
Posts: 2059
Joined: Wed, 16 Jul 2008, 00:21
Real Name: Paul
Location: Brisbane 1963

Voltron, the Electric RG!

Post by EV2Go » Sat, 18 Jun 2011, 16:52

Curious about the weld... how did you keep the cog true to the shaft centre line while it was welded?

Image

User avatar
jonescg
Senior Member
Posts: 3046
Joined: Thu, 21 Jan 2010, 23:05
Real Name: Chris Jones
Location: Perth, WA.

Voltron, the Electric RG!

Post by jonescg » Sat, 18 Jun 2011, 20:42

It was stepped on the lathe first, so that it fit snugly in place, Then the V was welded and finally smoothed off on the lathe again. Not me, though. I can't build anything to save my life!
AEVA National Secretary, WA branch chair.

User avatar
EV2Go
Senior Member
Posts: 2059
Joined: Wed, 16 Jul 2008, 00:21
Real Name: Paul
Location: Brisbane 1963

Voltron, the Electric RG!

Post by EV2Go » Sun, 19 Jun 2011, 03:01

ok so the cog should still run nice and true and have no chain issues :)

User avatar
jonescg
Senior Member
Posts: 3046
Joined: Thu, 21 Jan 2010, 23:05
Real Name: Chris Jones
Location: Perth, WA.

Voltron, the Electric RG!

Post by jonescg » Sun, 19 Jun 2011, 04:34

Yep Image

However, because of the alignment of the plates not being perfect, there is a bit of resistance in the shaft when I turn it by hand. So I backed off a few bolts and it turns freely. All I need to do is shim these bolts but of course I need to wait until Monday to do that (all the bearing shops are closed)...

This sucks because I can't put the bike back together until the shaft is 100% perfect. I can spend Sunday doing the 12 V wiring and tidy up the fairings, but the big job will have to wait. I can also finish the crate and get that ready at least.
AEVA National Secretary, WA branch chair.

User avatar
jonescg
Senior Member
Posts: 3046
Joined: Thu, 21 Jan 2010, 23:05
Real Name: Chris Jones
Location: Perth, WA.

Voltron, the Electric RG!

Post by jonescg » Tue, 21 Jun 2011, 04:29

Took the day off to finish re-re-reassembling the lecky bike. Started with the 12 V fuse box. Since my axillary battery uses the same lithium chemistry it can pump out a hundred amps no trouble, a few fuses are a good idea.

Image

Got the motors shimmed and the shaft turns freely Image So I set them in the bike, and started the long process of mounting al lthe batteries and terminating them. Only got shocked once this time! Image
Image

I tried to install Oggie Knobs but they don't stick out far enough. Oh well, I tried.

Crate is built and painted black. I need to get VOLTRON splayed across the side Image
AEVA National Secretary, WA branch chair.

User avatar
jonescg
Senior Member
Posts: 3046
Joined: Thu, 21 Jan 2010, 23:05
Real Name: Chris Jones
Location: Perth, WA.

Voltron, the Electric RG!

Post by jonescg » Sat, 25 Jun 2011, 00:19

OK everybody, Voltron is finally ready in it's latest and hopefully most complete state. Yesterday I got home early so I could put the chain on and go for a quick 'diagnostic fang' Image

And the motor bolts foul the chain Image

So in what must be the eleventh time, I fully disassembled the bike, pulled the motors out, split them, removed the offending buttonhead bolts and put them all together again. I had to re-shim the spacers as I lost track of which one was which. The bike was fully reassembled from parts in 4.5 hours. Quite proud of myself actually Image

Here's me looking a bit weary last night:
Image

So today was a matter of testing the bike (of course) putting the fairings on and getting a few proud photos, before crating her up.

Image
Image
Image
Image
Image

It rides quite nicely and the new stiffer suspension worked a treat! The new 14 mm master cylinder delivers much better stopping power - not bad considering the pissy little 27 mm callipers are at their limit. I only cracked 92 km\h on my breif spin around the block, but it's fair to say I did get there rather quickly. Vmin x Imax = 70 kW Image

What's that I hear you say? The tank must be uncomfortable? Yes, it is. But I can't fibreglass to save my life and no bastard would take my money to do it. So maybe I can find a willing soul over east who can do it.

Once crated, I rode the 'Bird up to Bunnings and borrowed a ute. I called on 5 other mates from UWA to turn up and help me hoist it up onto the ute. Not bad work for a case of Coopers. Watson's Transport are taking her to Sydney and delivering to the racetrack probably Thursday evening, and for a good price too Image

Phew, I am stuffed. Think I need a beer Image   
AEVA National Secretary, WA branch chair.

GRMarks
Groupie
Posts: 134
Joined: Sat, 13 Feb 2010, 18:14
Real Name: Glenn Marks
Location: Dandenong,Vic

Voltron, the Electric RG!

Post by GRMarks » Sun, 17 Jul 2011, 07:48

I read you came 3rd (glass half full etc), great job, did you have any problems during the races ? Any planned mods for the next round ?

About the fiber glass work - I have plenty to do on my conversion - and I hate working with it (the itch factor) that's why no one wants the job.
Regards

Glenn Marks

User avatar
jonescg
Senior Member
Posts: 3046
Joined: Thu, 21 Jan 2010, 23:05
Real Name: Chris Jones
Location: Perth, WA.

Voltron, the Electric RG!

Post by jonescg » Sun, 17 Jul 2011, 19:38

Hi Glenn,
Yeah, came 2nd in race one and DNF for race two. I cooked a motor in Friday practice because the controller was dialled up too high, and the motors went out of balance. I sourced a new motor in Sydney (thanks to the awesome efforts of some members of the Sydney AEVA!) and installed it that night. Was all good for race one; definitely the fastest bike in a straight line, but the 1985 chassis is ordinary for going around the tighter turns. I came 2nd as Catavolt has some battery issues, meaning they had to limp over the line. Race two was a bit of a disaster for me. I had a great start but the motors were out of balance again, meaning one motor took all the load. By the end of the first lap I cooked the replacement motor Image.

Still, third overall for points and 2nd (out of two Image) for the TTX75 class.

I will be back over East for the next race in Winton, and hopefully Agni will have sent two new, properly matched motors. I'll also dial the controller back to 60% to be on the safe side.

It's really expensive, this racing stuff, but a whole lot of fun. The entry fees are crazy high, combined with travel, accommodation and shipping costs, and that's before you blow up two motors! I have started a thread in the Perth Branch section to try to get some support for the entry fee costs.

It's awesome to be part of the electric racing scene. The only way we are going to push for better bikes and faster machines is if we race them to improve the breed. Any support from the EV community is clearly money/effort well spent.
AEVA National Secretary, WA branch chair.

Faz
Groupie
Posts: 96
Joined: Tue, 05 Jul 2011, 16:43

Voltron, the Electric RG!

Post by Faz » Tue, 19 Jul 2011, 21:42

I spoke to you briefly at the AEVA meeting the other week. You were saying you felt the chassis was letting you down. Are you sticking with this chassis or going to change over to something else soon?
A few months ago I saw two 2002 (or near that year) Hyabusa's for sale in the Quokka. They were only $2000 or so, minus the engines. The Busa engine is sort after by people making race karts/cars so might make a good donor bike.

If you need some fibre glassing help I'm happy to oblige. That tail really needs a re-build. Image

User avatar
jonescg
Senior Member
Posts: 3046
Joined: Thu, 21 Jan 2010, 23:05
Real Name: Chris Jones
Location: Perth, WA.

Voltron, the Electric RG!

Post by jonescg » Wed, 20 Jul 2011, 00:12

Hi Faz,
Yeah, the chassis was never really optimised for racing, even back in 1985. My next bike will be from a litre sports bike, maybe a CBR1000RR or a GSXR1000. Busa's are great, and a very popular engine to mod, but the chassis was pretty big, perhaps a little too big for a race bike. I will keep my eyes out for any mid 2000s litre bike chassis that are still in good shape. Even if I have to sell the IC bits.

If you'd like to help with the fibreglass, that would be FANTASTIC! I have been putting bog on the original metal tank to fill it out a bit before making a cast. It was just a bit too small to use the original, as the batteries sit a tiny bit too high, and the knee divots were a bit narrow. If I can provide you with the plug, chop mat and resin, can you make a cover for me? Also, an alternative to the current tail piece would be great, but the bike is over in Canberra right now so I can't take any measurements.
AEVA National Secretary, WA branch chair.

Faz
Groupie
Posts: 96
Joined: Tue, 05 Jul 2011, 16:43

Voltron, the Electric RG!

Post by Faz » Wed, 20 Jul 2011, 01:31

Yeah I figured the Busa might be a little bigger (and heavier) than you would really want.
Happy to do the glass work for you. Bare in mind I'm not a professional but have done a fair bit of fibre glassing in the past.
Rather than trying to bulk up the tank to get what you want have you thought about starting from a piece of foam. It allows you to create a complete custom shape without the limitations of the existing tank. Polyurethane foam is brilliant to work with, very easy to shape with basic tools. It is fairly expensive but allows the use of cheaper polyester resin (vs polystyrene foam).

Last edited by Faz on Tue, 19 Jul 2011, 15:45, edited 1 time in total.

User avatar
jonescg
Senior Member
Posts: 3046
Joined: Thu, 21 Jan 2010, 23:05
Real Name: Chris Jones
Location: Perth, WA.

Voltron, the Electric RG!

Post by jonescg » Sat, 06 Aug 2011, 00:03

Hi Faz,
I have finished the basic shape of the metal tank with bog. What should I do now? Coat it in some kind of epoxy to make it as smooth as possible? Spray putty?

It's pretty close, and I'd like to get it done soon so I can send it over east. PM me when you are ready to help out.
Cheers,
CHRIS
AEVA National Secretary, WA branch chair.

Faz
Groupie
Posts: 96
Joined: Tue, 05 Jul 2011, 16:43

Voltron, the Electric RG!

Post by Faz » Sat, 06 Aug 2011, 00:09

Spray putty would help depending on how good your bogging was. If you have sanded back the bog and have a reasonably smooth surface it should be o.k. I'll be using wax and release agents anyway so as long as it isn't badly pitted it won't matter. You work at UWA as well don't you?

User avatar
jonescg
Senior Member
Posts: 3046
Joined: Thu, 21 Jan 2010, 23:05
Real Name: Chris Jones
Location: Perth, WA.

Voltron, the Electric RG!

Post by jonescg » Sat, 06 Aug 2011, 00:21

AEVA National Secretary, WA branch chair.

Faz
Groupie
Posts: 96
Joined: Tue, 05 Jul 2011, 16:43

Voltron, the Electric RG!

Post by Faz » Sat, 06 Aug 2011, 00:43

PM'd
If you are in Perth on the 30th of August you might want to check out the Manheim bike auction.
http://www.manheim.com.au/brvm/items/31 ... ionListing
Nice little 2010 CBR1000 there.

User avatar
jonescg
Senior Member
Posts: 3046
Joined: Thu, 21 Jan 2010, 23:05
Real Name: Chris Jones
Location: Perth, WA.

Voltron, the Electric RG!

Post by jonescg » Sat, 06 Aug 2011, 02:05

Hot diggity! Hope it's in good shape, and better yet, cheap!
AEVA National Secretary, WA branch chair.

GRMarks
Groupie
Posts: 134
Joined: Sat, 13 Feb 2010, 18:14
Real Name: Glenn Marks
Location: Dandenong,Vic

Voltron, the Electric RG!

Post by GRMarks » Tue, 06 Sep 2011, 18:21

Chris congrats on wining both races at Winton raceway Vic. on the weekend. Your bike ran and sounded sweet. You are realy getting it sorted now.
Regards

Glenn Marks

Post Reply