Miles ZX40ST refurb project

[oatnet]

I've also managed to reconstitute a 25S3P module from a split up 28S3P module. I removed 3S from one of the halves and recompressed the rest with bar clamps. Using the original stainless steel straps, I stretched the strap back into position and welded the ends with a MIG wire welder.

After pulling 3s from the 28s pack, how did you join the halves to put them back in series? I've pictured cutting out failed 3p cell, but looking for a good way to join them back together.

Very cool project, I'm looking forward to watching this develop. White Zombie also had to use a pillowblock on the driveshaft, that should help. If you come across any more of those 300v 40a modules let me know!

-JD

 

[wb9k]

Not a lot of time to post lately, but progress has continued to trudge along on the truck. As always, there are lots more pictures at the photobucket album linked from the first post. First, I got some nice new pieces to replace the crummy old spline stub and slip yoke:

Spline engagement and fit is far superior with the new parts, as are the provisions for lubrication. I ordered the Tran Torque a couple weeks ago. They quoted a four week lead time but the part arrived here this week, ahead of schedule. I am going to have to have it partly bored out just a tad more, but everything looks good and I'm pretty optimistic about this revision. With so much downtime getting the driveline right, I decided to go ahead and mount the battery under the truck's bed without the driveshaft in position. My dad and I spent a very long Saturday getting things in place. We had to remove a cross member from the frame, and reconfigure another. We put the pack into position, then rebuilt the cross member and bracketry around the pack. The pack was lifted back out after the brackets were tacked into position.

Then the welds were completed, ground, touched up, and ground again. The result is not pretty, but is structurally sound. I laid down a few nice beads, but a lot of globby junk too.




Finally, everything is nice and sturdy with the pack in place:




I still need to put in a couple gussets on the rear brackets, then just a few holes drilled and paint. The removed cross member will be easy to replace at the top of the frame. There is room under the bed to bolt some angle iron into position. The position will be about like this:


Next big focus is CAN communications and what I hope are final details of the driveline. Also need to get serious about getting a charger picked out and set up. It's nice to have this big job just about behind me.

 

[wb9k]

Oatnet, sorry to take so long to reply to your question about the "reconstituted" prismatic module. The bus bars were cut such that the ends that needed to be connected were already touching after the module was banded. I stuffed copper foil into the gaps and flared out to the busbars and soldered the whole mess. It's not pretty, I won't be posting pics :lol: The technique is not suitable for high current (and I proved this to myself during some early road tests on the truck) but for the under 1C I expect to draw from the 85 Volt battery it should be fine. Maybe I can develop this technique into something worthy of posting pics and details about. I have other projects waiting in the wings that could make good use of it, so I may get there one day.

 

[wb9k]

OK, progress is painfully slow, but continues. First, I spent some time putting finishing touches on the pack mounts (rubber pads all around and gussets under the rear brackets:




Then I put together the new cross member that replaces the one that got cut out:




Finally, the Fenner Drives BK-Loc Tran-Torque device is in place with the new spline stub! It took more effort that I expected to get everything on straight, but it IS on straight and seems strong:


Tomorrow I take the driveshaft back with the new slip yoke to get it all put together. The actual shaft portion will be 1/8" shorter than it is now. I should be able to test the driveline at speed in a few days.

 

[oatnet]

OK, progress is painfully slow, but continues.

:lol: :lol: :lol: That sounds just like my experience with the Dune Buggy over the past 29 months. It looks like your project is coming together, so GOOD progress. Just keep plugging away and you will get there. I'm enjoying the pics so I hope you keep posting.

-JD

 

[wb9k]

Got the latest driveshaft on Friday and put it in on Saturday morning. I put the rear axle on jack stands and started testing. Things looked good. Vibration was very mild, nothing the motor mounts couldn't take up. I noticed that the motor tilted forward more than before under acceleration. This seems easily explainable by the much tighter fit of the splines in the slip yoke, and wasn't severe. Besides, that's what the bracket on the front of the motor is meant to deal with. I spun things up faster and faster, pleased with what was happening. Then there was a huge bang, and the shaft was lying on the floor. The rear U-joint was destroyed, as is probably the shaft's rear flange yoke. The slip yoke had also come off the motor shaft and the seal that contains the grease had disappeared. I still haven't found that piece. Then I noticed that the motor was slumped way forward from its balanced position. It didn't take long to figure out what had happened. That front motor mount was held to the motor with one of the motor's brush housing bolts. The washer I had put in place to retain the bracket was not large enough and had pulled back out of the mount, taking the rubber grommets there with it. That was it...one improper washer caused the whole drivetrain to grenade. The central bellypan piece my father and I made is badly damaged, though that can probably be repaired. The driveshaft is obviously bent. The trantorque coupler is destroyed, with amazingly heavy grooving cut into the sleeve interior by the motor splines. My dial indicator was nearby and was also destroyed. Best of all, I managed to actually bend the tailshaft of the motor itself. Obviously, this is a major setback. I probably flushed $1,000 down the drain in that moment. My dad was on his way down to do more sheet metal work this weekend, but instead we pushed everything to the back of the garage where it will remain for the rest of the cold months. I can't afford to just pick right back up from all that damage, so the project is now on hold until spring. Disgusted with myself doesn't really begin to cover it, I'm still wrapping my brain around the emotions of deep disappointment.

Not sure what will happen next. Right now I feel like I want to throw the whole damn thing out the window. I'll post some pics after I've got more distance between me and the event.

 

[riba2233]

OMG

Maybe you could use some small manual transmission, maybe the torque loading wouldn't be so high.

 

[wb9k]

OMG

Maybe you could use some small manual transmission, maybe the torque loading wouldn't be so high.

I think the torque load would have been just fine if I had just used a proper washer on the motor mount. Of course, I could be wrong. This mechanical s*%t has been kicking my ass for months now.

 

[Punx0r]

Wow, that was unlucky

When something like this happens I think it's best to walk away for a little while. Usually the anger and frustration turns back into motivation after a break from worrying about it.

Maybe you could put some photos up of the motor mountings? You might get some good feedback on whether they're adequate. I did raise an eyebrow when you said the motor tilts (presumably along its axis) under acceleration.

 

[oatnet]

I am glad nobody was hurt, which is the most important thing. I am sorry for your financial loss, but I think you were doing good work. Be proud of what you accomplished on, and learned from, the build -- with custom builds expect setbacks along the way. Putting it aside for winter gives you plenty of time to build up the enthusiasm to start again - or not.

-JD

 

[Hillhater]

Its at times like this that you can respect the amount of design thought that goes into any commercially built/sold vehicle , to avoid minor details becoming a major failure.
Imagine the amount of testing and redesign, retesting, something like a Tesla must go through.

 

[wb9k]

Ok, it's been months now, time to get my head back in this. I have a couple of forklift guys I need to go visit to weigh my options. Considering using a 9 inch motor if the right opportunity presents itself. Unfortunately, I don't have much money on tap at the moment, so that doesn't help. We (Dad and I) plan to take a more considered approach to getting the geometry absolutely right this time, and I now see that the motor mount system I had was inadequate for what is really a very substantial drivetrain--even if that damn washer had been adequately sized. More bracketry is going to be required to stabilize the motor's position, that is clear to me now.

The weather has been crazy mild up here the last week or two; it's looking like we'll have an early spring. I expect I'll get the project back unpacked and in a position to be worked on once the threat of snow is gone again--maybe in the next month or so.

 

[oatnet]

Glad to hear it, looking forward to seeing progress on v2.0!

-JD

 

[marcexec]

Keep going, mate. You'll get there and we'll be envious Bit for motivation:

"Nothing in the world is worth having or worth doing unless it means effort, pain, difficulty… I have never in my life envied a human being who led an easy life. I have envied a great many people who led difficult lives and led them well.”
― Theodore Roosevelt

 

[wb9k]

Thanks for the words of encouragement guys, I really appreciate it. I had kind of a rough winter with family issues and have been battling a bit of depression. Feeling better lately with the weather improving and motorcycle season back underway

I'm at a bit of a turning point with this truck. I recently inherited a 3-phase AC inverter and am considering going AC now. I'm sure this would result in a better vehicle at the end of the day, but it also makes the project more complex. I haven't tested the inverter yet, so this is still very much in the "mulling it over" phase. If I could get a small enough motor to mount directly to the differential, that would be a real plus. I have a line on a Leaf motor, but it seems much too large and heavy to try that with it. One other driver here is that it now appears that modifying the battery pack software to deal with the halved voltage/reconfiguration is a much bigger deal than I expected. Going back to 300 Volts would make that easier, but then I'll be forced to use either a higher voltage DC motor or an AC motor that can handle the voltage. 300 Volts is OK for both my DC and AC controller units, the motor is the wildcard here. So, I've got some homework to do. Any suggestions on economical choices for motors that can run in the 300 Volt range would be much appreciated!

 

[oatnet]

Have you considered using a Zilla DC controller? It'll take your 300v input and buck it down to whatever you program:150v, 96v, whatever. The -HV version is good for 300v input, the -EHV version 375v input. The Zillas were designed in the era of saggy lead-acid packs, and by bucking a higher voltage down you could still put out 170v no matter how bad the Pb pack sagged. White Zombie runs on Zillas, btw.

While Zillas are pricey new, I bought both of mine used for under a grand each, I'm sure you could find a similar deal with some digging. My Z2K (2000a) needed repairs but manzanita micro only charged me a few hundred to fix it - and it was really comforting to work with a reliable reasonable domestic manufacturer. I had Rich upgrade my Z1K (1000a) from a -LV (150v) to a -HV (300v) for a few hundred. I'm thinking about upgrading my 2000a Z2K-LV to an -EHV next, but that would be for a dual-motor project that could actually make use of 2000a. -EHV is only available on the Z2K.

I think the solitons do the same thing and would be another option, but I don't have direct experience with them so I can't be sure. Any of them would be cheaper than going to AC, and you would retain the superior torque of DC. (Oh wait I missed the AC inverter you just got...)

-JD

 

[marcexec]

Soliton junior will do 340V, more than enough power (you can limit motor voltage).
What's the outcome of the damage, motor beyond salvage?

 

[riba2233]

http://kostov-motors.com/tractionmotors/kostovevmotors%28ac-dc%29/seriesdcmotorsforelectricvehicles/k9hv/

I know it's not extra cheap, but not many others that are small, only some 11 inch models.

 

[wb9k]

Thanks for the suggestions!

The inverter, BTW, is a Semikron SKAI4001 with control electronics by Oztek. The Semikron uses IGBT's and is rated for 400 Volts, 400 Amps (or thereabouts). After looking MPaul's Leaf motor thread, I see that the actual motor proper is smaller than I thought, but still quite substantial.

I have not yet had a tech look at my forklift motor, but I have to believe that at the very least the central shaft would have to be replaced, possibly the entire armature. As important as concentricity is, I wouldn't want to try to straighten the tailshaft back out.

 

[Hillhater]

Take it to a motor rebuild specialist for a repair quote.
It may be your cheapest option if you cannot find another replacement.

 

[amberwolf]

I have not yet had a tech look at my forklift motor, but I have to believe that at the very least the central shaft would have to be replaced, possibly the entire armature. As important as concentricity is, I wouldn't want to try to straighten the tailshaft back out.

If the bending is not too bad, I suppose you could chuck the armature in a lathe, and turn down the bent shaft till what remains is straight. If it's still thick enough then, you can simply use smaller bearings, if it had to be turned down all the way past their mounting point.

If it's just the tailshaft, out past the bearings, then as long as it is still thick enoguh to support the torque you'll put thru it, lathing it down to fix the bending should work ok, I'd expect.


You could even use the motor itself *as* the lathe, as long as the bending is all outside of the bearings.

Disclaimer: I'm a hack, not a motor expert or mechanical engineer. But most of my redneck engineering doesn't fail.

 

[oatnet]

Woah, missed that your motor was messed up...

 

[JJ_Chicago]

Hello, I'm a proud owner of a Miles ZX40ST truck now. I've read through this thread a few times and think it is awesome! It is definitely a laborious venture but I'm totally in awe of what you've done. I've downloaded most of your photos and I'm going to refer them as I push forward on my refurbishment project.

My primary mission is to find a windshield. I have a really good smash on the passenger side of the windshield so it definitely needs to be replaced. I found one in Ghouzong, China but it was over $300 before the trade war started. I'm sure that has increased dramatically. If anyone knows of any windshields that would fit my truck here in the U.S., I'm all ears!

Thanks again for posting detailed pictures and conversations!

JJ

 

[Rmay635703]

What ever happened to this story?

I have a zx40 Van I am Temped to drop a gas Honda Insight Motor into but surprisingly everyone seems to have given up on this rigs lately