[kerrymann]

One step forward, one step back

The long awaited adapter and hub arrived today and for the most part it seems good except for a couple of issues which I will go into more later. I started by nailing a couple pieces of wood to my workbench to cradle the motor. The last thing I wanted was a 180lb chunk of metal to roll of the workbench on to my toes!

The adapter plate

The adapter is made of 3 pieces of aluminum plate that apparently have been water-jet cut. They are attached to the motor with 4 bolts that were included along with 8 flat washers (presumably to keep the bolt from shanking out) and 4 split washers. I normally don’t see plate this thick water-jetted because of the kerf from the jet fanning out. It is okay as long as you account for it by giving plenty of clearance to adjacent parts. I am not crazy about it for the mounting bolts but this plate is so thick it shouldn’t be a factor.

The first really issue is the hole in the plates for the hub is just barely oversized and the tolerance of the plate means it’s not quite centered on the shaft. Because there was so small of a gap designed between the hub and plate, this just bearly causes an interference. There is no play in the bolts mounting the plates to the hub so the hole in the plates must be opened up or the hub turned down (I think the best answer is both).

This really could have been avoided by making center hole ID (Inside Diameter) much bigger. All of that aluminum inside the 4 motor mounting holes is not doing any good. It doesn’t carry any load and is just dead weight that should have been just put into the recycle bin for the machine shop to get a few bucks back.

One last note on those split washers. In this application they are useless because you have to use the flat washers underneath them. Split washers only *work* when they make contact between the base part and the fastener. I will be using Loctite to keep these in place.

The hub

The design of the hub is… interesting. It looks like part of a cast shaft coupling that screwed into the actual hub by 3 M10? socket head cap screws. These screws alone would not be sufficient to carry the repeated +200ft-lbs torque of the 9” motor but since the coupling appears to be wedged in (kind of like a taper lock) when you clamp it up it should be strong enough. The hub is also larger in OD (Outside Diameter) then it needs to be which like the ID of the adapter is un-necessary weight and leads to the interference above but also causes a interference with the flywheel. The flywheel has a recess that would normally go around the end of the crankshaft. The hub is considerably larger OD then the original crank so it does not fit inside.

I am going to email Electric Car Company and we’ll see what they say. I am sure they will fix the issues but it's a matter of how long it will take. I have a feeling I may be borrowing some lathe time soon to turn down the hub OD and opening up the plate IDs myself just to make it happen faster.

One other issue is I don’t have bolts for the flywheel. :-( This is 100% my fault because I should have resused the ones from the engine. But I left the old clutch and flywheel on for the guy who bought the engine as he was converting from auto to manual. Oops.

[TigerNut]

Maybe you can use the other three holes in the adapter to install dowel pins? You'd want to be sure that those never crept out and gouged their way around the motor bearing... but it would more than double your torque capability.

Is there anything on the three waterjet-cut plates that registers them together, and centers the motor and transmission using the OEM dowel pins and the motor's bearing end register? If not, you can easily be far enough out of alignment between the motor shaft and the transmission shaft to cause long-term bearing life issues. The typical alignment error on an OEM engine to transmission bellhousing is under 0.005" (that's the maximum runout limit suggested by Lakewood) and probably more like 0.002".

[kerrymann]

Originally Posted by TigerNut

Maybe you can use the other three holes in the adapter to install dowel pins? You'd want to be sure that those never crept out and gouged their way around the motor bearing... but it would more than double your torque capability.

Is there anything on the three waterjet-cut plates that registers them together, and centers the motor and transmission using the OEM dowel pins and the motor's bearing end register? If not, you can easily be far enough out of alignment between the motor shaft and the transmission shaft to cause long-term bearing life issues. The typical alignment error on an OEM engine to transmission bellhousing is under 0.005" (that's the maximum runout limit suggested by Lakewood) and probably more like 0.002".

The lack of registration is a concern of mine as well (among a few others). There is a reason the original engine had 2 large dowel pins that engauged the bellhousing, for alignment, just as you said. Then add the tolerance stack-up of 3 plates that are waterjet cut and it's no strech to think it could be out as much as .030". Measuring the misalignement of the hub to the input shaft isn't easy though...

[TigerNut]

Originally Posted by kerrymann

The lack of registration is a concern of mine as well (among a few others). There is a reason the original engine had 2 large dowel pins that engauged the bellhousing, for alignment, just as you said. Then add the tolerance stack-up of 3 plates that are waterjet cut and it's no strech to think it could be out as much as .030". Measuring the misalignement of the hub to the input shaft isn't easy though...

Maybe try talking to Flyin' Miata and see if they have coordinates for the dowel pins and bellhousing bolt locations relative to the OEM crankshaft center. That would give you one side of the answer, anyway... then you'd have to determine how to register the motor drive end on the last plate, and key the three plates together.

http://www.flyinmiata.com

[Tesseract]

Originally Posted by kerrymann

The lack of registration is a concern of mine as well (among a few others). There is a reason the original engine had 2 large dowel pins that engauged the bellhousing, for alignment, just as you said. Then add the tolerance stack-up of 3 plates that are waterjet cut and it's no strech to think it could be out as much as .030". Measuring the misalignement of the hub to the input shaft isn't easy though...

Did you consider (and reject on price) this Rebirth Auto adapter for the Mazda Miata?

[kerrymann]

Originally Posted by TigerNut

Maybe try talking to Flyin' Miata and see if they have coordinates for the dowel pins and bellhousing bolt locations relative to the OEM crankshaft center. That would give you one side of the answer, anyway... then you'd have to determine how to register the motor drive end on the last plate, and key the three plates together.

http://www.flyinmiata.com

This morning I measured the mis-alignment between the center of the adapter and the motor shaft and it is 0.035" (.070" total runout). This doesn't even include the slop and mis-alignment between the bellhousing and the plate which is probably going to be another .005-.015. The only "fix" I see to these issues is to lathe the hub down so it fits the flywheel, and chuck the 3 plates into a mill to open up the ID and add registration pins. Based on the experience so far I don't dare to hope this will happen
quickly. I am at the point where I asked to have to return this,
get a refund, and buy from another supplier. We'll see what they say.

Originally Posted by Tesseract

Did you consider (and reject on price) this Rebirth Auto adapter for the Mazda Miata?

Yes... I did. Ironically that part was what I was originally planning for but I believe last summer when I spec'd it was about $900 shipped as opposed to $1300 shipped. I guess I had a hard time swallowing paying more for the adapter then I did for the motor...

In hindsight I am wondering if I should have skipped the cost of the clutch and adapter and just gotten a Transwarp 11 motor and gone direct drive for the same price. Of course direct drive has it's own considerations....

Kerry

[kerrymann]

Motor Dry Fit!



Well I am still in discussions with Electric Car Company about my adapter. I just heard from Steve at Rebirth that a adapter from them will be a 7-10 day lead time. Lesson learned...

So yesterday I pressure washed the 178,000 miles off grease of the car so when I work on it I don't look like a coal miner.

And tonight I deiced to go ahead and dry fit the motor without the hub. I first needed to layout the motor cradle so I found a short section of heavy wall 1.25" pipe that had a nice tight fit over the input shaft. This allowed me to measure the height and see that the cradle fit really well if I welded it to the sub-frame.

The cradle is the same style I used on the leadwing. It's actually a mount for large high pressure cylinders (9" OD) in military ships. It even comes with a warranty plate circa 1988. Either way it is very stout, comes with all the hardware, and was $30 for two of them shipped!

It will need some modification but for now I just tacked it into place to dry fit the motor.

I am glad that I went with the 9" motor as once I put on the adapter on the assembly weighed over 210lbs! This really wasn't bad to lift, carry and man-handle into place, but if I had a 11" (~350lbs) I would have definitely need a hoist.

Anyway the motor fits in really well. I am going to trim the cradle away some before I weld it all in as I think I can lower it about another 1" to give a little better CG. Seems excessive but this is the heaviest single item on the car.

You can also see the the great space in front of the motor for one of the pack modules (with the help of my assistant). I was originally planning on splitting the pack into 2 modules but it would be a little too long. So I am going to do 3 instead to fit between the the frame rails.

[kerrymann]

I also test fit the controller. That Soliton1 is such a great piece of eye candy that I couldn't tuck it off into a corner. So just like on the leadwing I am going to put it front and center. I am considering 2 options: This first is mounting it parallel to the motor. Looks nice and would be fairly easy to mount.



And a 4 year old in thedriver's seat making motor noises makes it even better

I might even put it in a bit of an angle just to show it off more and get a little more clearance in the front for the pack.

The other option is to put in perpendicular. I am planning on putting in a strut tower brace so it would be REALLY easy to mount the controller and it hides the wiring by pointing toward the firewall. But it doesn't look right.... I'll do some more head scratching but I am leaning towards putting it in long way. I think if I did it sideways it would be a detail that would bug me.

Of course every knows that blowing bubbles on your controller is good luck for an EV....

If only the adapter was correct I would be really close to hooking up a few SLAs and driving arounf the driveway....

[kerrymann]

Getting the charge on the charge card



A bit of an update on the project. I haven't done much on the actual build due to the adapter woes but I have spent a fair bit of money.

I ordered and received my batteries! 250 A123 cells with full tabs. I really wonder when the delivery driver looked at the shipment he had thoughts of being used as a drug mule.

The bad news is my PL6 died but the good news is the warranty replacement is supposed to arrive Monday. Once it arrives I will start taking data and post the results here:

http://www.diyelectriccar.com/forums/showthread.php/standardized-pl6-testing-a123-cells-and-71283.html


I got my cable and crimper and connectors so I can start making up my cables. I was able to find a good US made bench top manual crimper, new for a decent price. Luckily for me the seller didn't do a good job of describing it on ebay and it took 30 minutes of websurfing to find out exactly what it was. http://www.uzengprod.com/ I wanted a crimper that, when used with the right terminals, would be UL listed and would have at least 3 crimp points. I did some searching and found most lug install specs require a minimum of 3 crimp points (NASA says 4 but this isn't a spacecraft so that eliminated all of the cheap crimpers except the the Chinese green lee hydraulic knock offs. I will gladly spend a few extra buck for an American made product.

The connectors are new Molex lugs and the cable is very good 2/0 bright orange cable (safety requirement for first responders) that I ordered from Trystar. I like to buy in bulk and so I have enough to do 4 or 5 cars. I am thinking about offering to make cables for whom ever doesn't want to go out and buy a good crimper and do it themselves. When I did the Leadwing I used a battery cable company but they were pricey for cables over a few feet.

[kerrymann]

Not-so Adapting Adapter



I emailed Electric Car Company and told them I was returning it for a full refund and asked for a return shipping label. A few days later I received a return shipping label but no other communication from them. I mailed it out and hope to get my refund soon. BTW that adapter weighed in at 28lbs!

So I went ahead and ordered the performance adapter from rebirth auto since they said 7-10 day turn around.

http://rebirthauto.com/mazdamiatamotoradapter.aspx