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Brian,

What you state is all that I've been able to find as well. At best I've been able to dig up a stall torque. Nothing about max RPM, efficiency, etc.
Efficiency is one of the data items in the performance charts for Netgain's brushed DC motors, but only for the speed range of the test. They only publish data for 72 volts supply voltage, but here it is in what I find to be a more useful form... but it's the same data as their graphs so it still doesn't cover most of the working speed range of the motor.
 

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I love a build thread that multiple people are excited about!

Mike - Don't look at Ebay or craigslist. Look up every forklift repair place in your area. Show up in person and ask if they could keep an eye out for 9" DC motors on any lifts that they're scrapping and to give you a call.

Offer to pull the motor out yourself, with your own tools, if they'll let you, they might.

Depends on the shop, some might go through the effort of taking them out (if it's not removed it's worth 1% at the scrapyard as it'll get attributed to basic steel rather than copper/iron). They might have some available that they'll sell you for scrap price or slightly less.

Scrap prices are currently low, so, $100-200 is about a fair rate.

If the first place says no, ask another.

They're functionally bulletproof. Make sure it's not rusted all to hell or corroded inside, and has intact brushes (you can see them), maybe bring a spare car battery to see if they'll spin up.

Brush advancing is as simple as drilling 2-4 holes and rotating a plate a few ballpark degrees. It's not super precise.

Brushes last just about forever.

You'll give up regen. This is about a 5-10% difference in range, way less than everyone presumes.

And then boom, save $2000. Build your own controller from several of the plans available, boom, another $1000 saved probably.

Put the rest into beer and batteries.
 

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Discussion Starter · #23 ·
The motor performance graph shown by EVWest appears to be from Netgain, but is for 64.5 volts RMS at the motor or 96 V DC supply, which doesn't match the EVWest package description (of 120 V); it doesn't even look quite like the 96 V grapsh published on Netgain's website. The shape suggests to me that it might be for the HV motor, but it's not labelled that way and Netgain only publishes 120 V and higher for the HV. SME does not publish details for the specific motor which they supply to Netgain.
This is exactly what I'm referring to. I'm not sure where the graph came from, but it makes it seem like high efficiency isn't achieved until almost 3000RPM, whereas all other charts show it around 1200RPM. I can work with low efficiency up to 20mph, but no up to 50mph!

I really appreciate the input! Now I'm itching to get started on the car, but I've got to finish renovating the garage first!

I did just think of one other question on going direct drive. Will I need to allow for axial play between the motor and final drive? If I understand correctly, the TransWarp 9 has a slip-yoke spline for the U-Joint output to allow for some axial play. Will I need to devise something like this? I was hoping to just mount one of these below on the motor shaft and just hook directly to a custom length drive shaft. Allowing axial play will definitely be a challenge, but should be doable if needed. I'm just not sure if it's actually needed!

http://www.evwest.com/catalog/product_info.php?cPath=44&products_id=428
 

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Discussion Starter · #24 ·
Brian,

I totally missed your second post! That's the first curve set I've seen for a DC motor. And yes, the range I really care about (<1000RPM) is completely skipped. That seems like a very important region to neglect, even for mounting up to a tranny.

Matt,

Welcome to the thread! I'll do some looking and make some phone calls this week and let you guys know what I find. I still prefer to go Hyper 9 from a technical point of view, but that much potential savings is hard to pass up...

I usually take the approach of using whatever is cutting-edge technology and somewhat reasonable price wise. Part of my desire for Hyper 9 is somewhat ego driven. Being able to quote high efficiency and point at leading technology is a big plus to me. That said, pointing at an old forklift motor and a homemade controller has it's own ego boost as well. OH THE DECISIONS!!! I'll have to do some serious thinking if I come across a deal on a good DC motor.

On advancing timing real quick. About how much is timing usually advanced? And I'm assuming you just change the rotational location of the commutator end plate? Lastly, by advancing the timing don't you lose the ability to use a reversing contactor for reverse? So therefore I'd need to keep the tranny?
 

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I did just think of one other question on going direct drive. Will I need to allow for axial play between the motor and final drive? If I understand correctly, the TransWarp 9 has a slip-yoke spline for the U-Joint output to allow for some axial play. Will I need to devise something like this? I was hoping to just mount one of these below on the motor shaft and just hook directly to a custom length drive shaft. Allowing axial play will definitely be a challenge, but should be doable if needed. I'm just not sure if it's actually needed!

http://www.evwest.com/catalog/product_info.php?cPath=44&products_id=428
There will be some movement of the final drive in its mounting bushings, so there needs to be either some axial freedom in a component of the shaft, or some longitudinal compliance in the motor mounts. Vehicles always handle this in the shaft (not by having the shaft shift the engine and transmission), and I wouldn't to depend on motor mount compliance, for the sake of the motor bearings.

EV West may be counting on that compliance, or assuming that there is a plunging or slipping section of the shaft. Allowing the transmission output yoke stub to plunge is common, and what the TransWarP motors are set up to do; however, in some propeller shafts there is a slip joint (splined and sliding section of the shaft), especially in the rear section of a two-piece shaft (which has a support bearing midway between the transmission and the axle). The most straightforward way to avoid problems would be to use a slipping section of shaft with that fixed yoke on the motor.
 

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Discussion Starter · #26 ·
A sliding spline drive shaft sounds like the ticket for sure. Axial loading the drive shaft is just going to wear out U-joints. Looking real quick online it looks like some Triumph drive shafts are the sliding-spline type. I'll have to see what mine has when I start pulling it apart. Worst case I think I'll just have to find a sliding spline drive shaft from a different vehicle that is the correct length. I still have no idea where the shaft of my motor is going to end up in the transmission tunnel.
 

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A sliding spline drive shaft sounds like the ticket for sure. Axial loading the drive shaft is just going to wear out U-joints.
I agree, but the rear suspension of a Spitfire carries all of the lateral load through the axle shaft U-joints... which seems to work.

Looking real quick online it looks like some Triumph drive shafts are the sliding-spline type. I'll have to see what mine has when I start pulling it apart.
I didn't even notice if our Spitfire has a sliding section; if it does, the problem is solved. :)

Worst case I think I'll just have to find a sliding spline drive shaft from a different vehicle that is the correct length. I still have no idea where the shaft of my motor is going to end up in the transmission tunnel.
Or get one made up, with the appropriate yokes; it's a routine service from driveline specialty shops.
 

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Discussion Starter · #28 ·
I think everyone agrees that the axial load on the half-shafts is a bad idea though. Triumph got it to work in that application, but I wouldn't count on it elsewhere.

I just tried crawling under the car, but I still can't tell what style driveshaft mine has. I'll just have to wait to find out I guess. And yes, when it comes that time I will find a drive-line shop and just have them provide one. Whether it's custom made or an off the shelf I really don't care. I just want it to be professionally done. Last thing I want is my DIY driveshaft vibrating like crazy or separating!
 

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Hey, I haven't visited in a while and am happy to see another Spitfire conversion ongoing!



I really love driving my '79 Spitfire. You've probably looked at my thread by now, but I started out planning on direct drive. After working through the numbers I decided it wouldn't have the performance that I wanted out of the build (I do like the jackrabbit starts off the line) so I switched to a Borg Warner T5 (1352-246). The gearing matched what I had spread sheeted as an ideal (for me) performance.



During normal around town driving I usually start in 2nd gear and shift to 4th. It is nice however to have 1st for the fast starts, and overdrive for highway driving -- it has no problem doing 85mph. My spreadsheet of the overall performance predicts it would have a top speed of ~120 @ 4900 rpm in overdrive.


I'm looking forward to seeing your build progress...
 

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Discussion Starter · #30 · (Edited)
Baratong,

Thanks for the input on direct-drive vs. tranny. I'm still torn. I'm not terribly concerned about performance, so I think Direct with the Hyper 9 will work. If i go that route then my backup plan is to make a small single speed "transmission" that will bolt onto the face of the motor. AC will allow 6-8k peak RPM, and going direct drive only lets me realistically use about 4k rpm. A ~1.25 ratio at the motor would be very helpful....

On your thread, I started reading it last week, but actually just finished tonight. I'm amazed by your BMS system. Your electronics skills are lightyears ahead of mine. That said, I'm leaning towards an Orion for the simplicity. In your experience, is this a good option? Or what else should I consider?

Also, on your batteries, what drove you to use LiFePO4 bricks? It looks like you started in 2014. Were there production lithiums available at the time or were the bricks the only real option? I'm planning to use Gen1 Leaf Modules because they're about $150/kwh and a lot more energy dense than LiFePO4. What are your thoughts on Li-Ion vs LiFePO4?

Kevin
 

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Discussion Starter · #31 ·
Well, no luck on finding a forklift motor locally. I looked around and could only find one shop that actually repaired/serviced forklifts within 2 hours of here. I talked to them for a few minutes over the phone, told them what I was looking for and why. They said that they hardly ever get any electric fork trucks in and it's once in a blue moon that it would actually be scrapped out. He couldn't even remember the last time they had an electric one in. He did say that they sometimes will have the smaller walk-behind style, but it's my understanding that the motor on those is a little too small.

Anyways, I'll still keep my eye out for a good deal, but I'm just going to stick with the Hyper 9 plan.

On another note, I'm about halfway done renovating my garage, so I'm getting closer to actually starting on the Spit!

Kevin
 

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Consider me subscribed!

My E-Fire was a lovely beast- unfortunately it was destroyed back in July by an inattentive driver changing lanes in a big pick-up truck.

A few cautions with your plan:

1) Use production EV batteries from a wrecker- Volt, Leaf etc. Give up on the LFP bricks because they are handy but way, way too expensive and regrettably not getting sufficiently cheaper.

2) Use a BMS. Minimally necessary safety equipment. 'nuff said on that.

3) Throw away the Triumph transmission- it's not up to the job.

4) I vote for keeping a tranny so you have speed/torque options. It improves the fun factor of driving by a lot, in return for very little efficiency loss and extra weight. I used a Toyota W50 in mine but you can use any number of options. Making a transitional driveshaft is comparatively easy if you have a lathe and a welder, but a driveline shop can do it for you too for not too much money.

5) The weak spot is the differential and the half shaft u-joints. The suspension transmits thrust when cornering through the U joints into the bearings of the diff. Go with greasable ones and then you do need to grease them. Changing them properly requires removal of the whole axle assembly which involves disconnecting the brake lines- messy but you get good at it rather quickly. Drill a drain hole in the diff casing so you can change its oil.

DC will not give you regen braking so that will mean you'll be relying on the original brakes- front discs, rear drums. That's OK as long as you know that the car's acceleration performance will not be matched by its braking performance...and no "free" power brakes either. You're going to have to step on them hard to lock them up.

Do a good job with the transmission mounting plate and hub or else you'll burn up transmission input shafts and bearings. Tolerance is about 5 thousands of an inch, not more. I pushed the "easy" button and bought a plate and hub from CanEV- motor installation took at most an hour all in and installation precision was perfect.

Depending on what my insurance company finally offers me (it took 3 months just to get an insufficient first offer from them), I may be looking for a new clean Spitfire. Anybody in the US who sees a nice clean one- no rust, needing minor body work and paint is OK- with a blown engine, say an Arizona/New Mexico/California car, I might be interested- send me a PM if you come across a real beauty. Not yet, and not at all for certain- I may be stranded without enough money to make re-doing an E-Fire Mark 2 a worthwhile effort.
 

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Discussion Starter · #33 ·
Molten,

Thanks for all of the feedback. I absolutely agree with 1, 2, and 3. For the batteries I'm planning to use Gen 1 modules from a Leaf. That may change to Gen 2s depending on price when I go to buy. BMS if a definite (planning to use an Orion BMS since I'm rather ignorant on the topic). And I'm certain that the Hyper 9 would destroy the tranny and probably the final drive if I left the Tranny.

On the talk of the tranny, I'm still torn about using one or not. RPM wise, direct drive works out very well (~3400 rpm at 60 mph). Being an SRIPM motor, the Hyper 9 has near full torque at ~0 rpm all the way up to ~3600 rpm. Correct me if I'm wrong, but I believe that DC motors don't get full torque until ~100 rpm (can't remember where I read/heard that). If that's true, then I can see needing a tranny to get off the line with a DC motor (or pure inductance AC), but maybe not with the Hyper 9.

A 2 speed transmission seems like it would be ideal, but I'm not willing to pay $3-5k for a powerglide (or similar). I've kicked around the idea of building my own ~1.25:1 single speed transmission and pushing the motor RPMs up into the 6000 rpm range at highway speeds. If I go that route then I'll definitely have to do forced air or liquid cooling on the motor though, as it's continuous rating is only 3300 rpm.

It all really depends on what performance is going to be like and what I think I need (which I have no idea...). The car currently has the week 1500cc motor in (with problems), and I'm not very good on stick and it still seems to scoot about with plenty of pep (when the carb actually feeds fuel :p).

On making a custom drive shaft or adapter plates. I have a full size mill and lathe as well as welders, grinders, etc. I think I can make just about anything I need, although I'll probably pay to have a proper drive shaft made. I'm really excited to get started. Just have to finish renovating the garage first! Almost done wiring, next up is insulation....

P.S. I didn't mean to put the angry face on the subject line...
 

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hi Kilomike.
I have over the years gone through this process and collected all the parts for my Spitfire build. Struggling to find the time to get started, life, business etc. but business sold now, so should be soon!
FYI, the powerglide i also looked at and purchased, but decided to use on an alternate project, as the size is rather prohibitive. i also looked at W58 5 speed but felt was over kill... in the end for what it's worth. i decided on a UQM 100kw 300nm motor with direct drive. I've made and sold a dozen kits to fit a Subaru diff direct into the spitfire chassis. I've opted for a LSDV (viscose) 4.44:1 diff. the numbers suggest a 6.7 sec 0-100klm. hope to put a build site up once i get started.
 

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Discussion Starter · #36 ·
Duncan,

I assume that's with a transmission and in first or second? Either way, impressive! I am hoping to avoid that though. Prefer to not break the wheels loose... It would be cool to be able to for showing off, but nowhere near a design goal.

EVSpitfire,

Sounds like you'll have quite the setup! A quick search on that motor shows some impressive specs. 221 lb-ft of peak torque, 80 HP continuous. Far better than the 173 lb-ft peak and ~50hp continuous of the Hyper 9. Alas, the cost and voltage is prohibitive for me though. Looks like ~$6500 and 300+VDC compared to the Hyper 9's ~$4200 and ~100VDC. I don't need a huge battery pack,so getting that kind of voltage would be tough for me. Either way I can't wait to see how yours works out! Your 0-100kmh should be impressive!

I am very interested in your subaru diff swap! That ratio would be perfect for what I'm wanting and word on the street seems to be that they can actually handle the instant torque of electric. Is it a direct sub for the diff, or do you also have to make major suspension mods? Any info you can share or point me to would be great. I'm already betting 50/50 that my diff will implode in the first year.

I can't wait to see your build thread/site!
 

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Duncan,

I assume that's with a transmission and in first or second? Either way, impressive! I am hoping to avoid that though. Prefer to not break the wheels loose... It would be cool to be able to for showing off, but nowhere near a design goal.
Nope - direct drive to a Hitachi forklift motor - no gearbox

And - this may be relevant - through a Subaru LSD
 

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Discussion Starter · #38 ·
WOW!! I didn't expect that could be a direct drive. Do you know what kind of torque it puts out at low rpm? I wonder how much more it is than the Hyper 9.

And how difficult was the subaru diff swap? Rough math suggests the triumph diff **should** be able to handle the torque of the Hyper 9, but I don't have that much confidence.

Kevin
 

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Hi Kilomike

I started with a Subaru diff - complete Subaru back end - and front end as well!

But EVSpitfire is talking about putting a Subaru diff in a Spitfire - which sounds to me like a very god idea!

Don't know how much torque - I have bought some nice new sticky rear tyres "Nitto" - they say "recommended not for highway use" on the sidewalls - and the damn thing still breaks them lose - but a lot more controllably

I am feeding my Hitachi with 1200 amps and 340 volts - and I did kill my first one at the Drags last march - but I got another for $150 (and a "spare" for $200)
 

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Discussion Starter · #40 ·
I am feeding my Hitachi with 1200 amps and 340 volts
That has to be ridiculous amount of torque!!!! I'm planning for 100-120 volts and ~700A peak. I'm doubting mine would break the tires loose if I go direct drive...

Where are you finding such motors for so cheap? I tried the 'local' forklift place (closest one is 2 hours away) with no luck. Said they almost never work on electrics anymore. I see motors that look like they could work on ebay for ~$1k (maybe $600ish), but I don't know enough about them to confidently buy. I'm also not thrilled with the idea of a reversing contactor for reverse (assuming I go direct drive).
 
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