More Motor Mania

My wife says I'm "like a kid sometimes". I will not deny it. The motor arrived from D&D Motor Systems (http://www.ddmotorsystems.com ) and it was just like Christmas for me.

I threw the motor on the scale and it weighed in at a whopping 64.5 lbs. with the factory supplied mounting bracket.

I laid the motor inside the frame, just to get a feel for placement. It's going to stick out quite a ways on the right side of the frame. Fortunately it's a good looking piece of hardware.

Motor Madness

I've finally comitted to a motor: D&D ES-15A-6. This motor is heavier (62lbs), a little more expensive and much larger (~12.5" long) than the Etek-RT that I was originally thinking of using. I'm sure the Etek would have done the job, but in the end D&D's reputation for quality & customer support was the deciding factor.

If you have done any browsing of EV projects, you know it's fairly common to have problems with ordering parts from the cheapest source. I've spent enough time in the manufacturing arena to know some of the pitfalls in supplier selection. Up front cost is only part of the equation.

With the motor specified (and on it's way!!) I'd better get serious and figure out how to mount it. I see a lot of guys use the NEMA face mount by welding a plate to the frame, but that is not going to work on El Gixxer. Welding is not an option for this project, so the trick for me is using the existing rear motor mounts on the frame.

One advantage the D&D has over cheaper motors is that it can be mounted using the case as a structural member. The motor even comes with case bracket for mounting on flat surfaces. My idea is to use some 1.5" x .75" aluminum stock to make a couple of mouting struts. Once the motor arrives, I will make a wood model to try it out.

Batteries & Babbling

Up until recently, I've been fairly comitted to using LiFePO4 batteries. I was leaning toward ThunderSky 60AH, but the physical layout of the cells didn't look great in my mockup. Maybe one of the other suppliers would work better?

Therin lies the problem. Distribution channels for Lithium batteries are not established in the US. Sure there are dozens of people who will import them, but I'm not a big fan plopping down thousands of dollars for a product without support .

The only brands actually being sold in the US are from overseas based companies. The US based manufacturers won't even sell their batteries to a non-OEM manufacturer. Sure, they have a link on thier website to "tell us about your application", but what they really are looking for is someone ready to place a $500,000 order and wait a year for the product. I've exchanged emails with A123, Valence and EnerDel, just looking for more information, only to get the go-jump-in-a-lake reply. (In hindsite, I may have replied a little hastily to those emails.....)

The asian suppliers have thier issues too. ThunderSky doesn't have a decent BMS system, while LifeBatts are built-in and slick but very spendy. Interestingly enough, I have written to both and gotten prompt, informative replies.

So, I'm really stuck. Normally an EV conversion hinges on battery selection, and fitting the trays around them. What if my trays are more generic, allowing for multiple battery formats? It's easy to add spacers or mounting holes after the battery selection is made.

The key is still optimizing the use of space for batteries within the frame. So I still needed to grind a few thing off the lower frame rails. (For comparison, see the cardboard mockup, several posts back)

Diversion into detailing

I know, I know..... I'm supposed to be mapping the frame geometry and working on the solid model. Unfortunately, other things (that pay the bills) have been dominating my time latley.


I did have a little time to sneak out to the garage and do some detailing on the frame, and experimenting with polishing various surfaces. I'm toying with the idea of turning this bike into a "street figher", because I can't bear covering up the frame.

The frame is an intricate combination of sand castings, die castings and extruded sections. Most of the less visible castings were not cleaned up very well, with rough parting lines, and even sprues still attached.



The steering head is a large sand casting and really needs some help. The sprue remnants were driving me crazy (have you picked up on the anal retentive tendancies), so I ground them off. I then used progressively finer sandpapers on the surrounding cast surface, and finished up with some 000 steel wool, and some Mother's aluminum polish.

The results aren't quite "mirror-finish", but pretty good for a rookie, IMHO. I may need to go one grade higher on the sandpaper and do "00" and then "0000" with the steel wool.

Hopefully, I will be able to get away for few hours sometime this week to get the dimensional layout done.

Stripped Naked

I finished removing the front end tonight. Now it's just a frame and a welded sub-frame. The frame feels a lot lighter than it looks. I'm guessing around 30 lbs, but I will weigh it to be sure.

Why strip the frame completely? Isn't that overkill, just for an EV conversion?

Well, now the fun begins: reverse engineering the bike. The next few weeks will be spent measuring the frame geometry in order to build a 3D cad model.

GSXR 750 Swing Arm Removal

Time to remove the rear end of the Gixxer. After some second class carpentry to create a stand, I was ready to remove the rear end.

The upper mount of the shock was attached to the frame by four socket head cap screws threaded into the strut between the frame rails. I've never seen so much lock-tite in my life. Aluminum threads are notorious for tearing, so I reluctantly used a 16" piece of pipe to extend the leverage on my allen wrench. Even after breaking them loose, it took a lot of force to back them out.

The swingarm pivot shaft came out easily, but the swing arm remained in place, because of a threaded spacer. I browsed some Gixxer forums, and learned my options were to buy a specialty tool ($$), use a hammer and screw driver (ouch), or make my own tool.

My tool consists of a 5/32 hex wrench, ground to fit between points in a 32mm socket. Note the angled ends of the hex wrench. Worked like a charm.

Battery and Motor Mock Up

According to my research, every EV project has to do a cardboard mockup of the engine and battery placement. The point of the mockup is to get a good idea of what is going to fit, and what is just not going to work out.

Even though I'm planning on replicating the frame in a solid modeling program, I thought it was a worthwhile exercise, revealing a couple of potential problems. Note the can of Sherwin-Williams finest representing the motor (same diameter as a D&D or Advanced DC).

My first cardboard revelation was that it's a lot tighter fit than I thought it would be. I modeled the 60AH ThunderSky batteries, but they are a smidge too big to fit in some orientations. The second eye opener was that a few of the original mounting lugs will need to be ground off, to let the batteries sit higher. I hate to grind anything off, but there is just no way to utilize the space between the frame rails without doing it. I think the remaining lugs will be sufficient to hold the motor and battery frame.

The motor will fit decently, assuming I use an ADC or D&D type. The paint can is 6.75" in diameter, compared to 6.7" for the D&D. An Etek-RT will just make it, but it will be a tight squeeze at 8.07". There is no way a Perm132 will fit inside the rails (8.75"), and I'm not wild about mounting the motor outside the cage.

I'm planning on mounting the controller and other electrical connections between the upper frame rails. The hollowed out gas tank will cover everything nicely, but may need some venting, or a fan to keep everything cool.

The prolific use of duct tape, although not permanent, would make Red Green proud.