DIY Electric Car Forums banner
161 - 174 of 174 Posts

· Administrator
Joined
·
6,613 Posts
Thanks again Duncan. I got you... But regarding the 100 KMH at 2000 RPM, there is nothing I can do since it is the current built in mechanism characteristics. But I will try to find a controller to have the ability to cope with it and, as I said before, provide a battery pack that will supply higher voltage than the nominal voltage of the motor. This will leave the controller to adjust the voltage to cope with the torque (current) demand at higher RPMs. Sounds good?
If you are keeping the transmission simply use a lower gear
Top gear may be 2000 rpm for 100 kph - but lower gears will be more revs - first gear is usually three or four to one
So in first it will be 6,000 to 8,000 rpm at 100 kph

Keeping the revs up will reduce the heat as the motor will be spinning faster and you will require less current

You may well find that you never use "top gear"
 

· Registered
Joined
·
13 Posts
Makes very good sense to me... Thanks a lot!
But thinking at loud, if the lower gear RPM is too high, I may end up with a mechanical problem. But I am sure you have a point, I will have to fine tune the selected gear with the proper RPM to take down the supplied current while cranking up the RPM. But my point is that it will not be a tuning based on "the the highest RPM is the best" scenario because of mechanical restrictions. I will figure out all of this on my workbench.
 

· Registered
1971 MG BGT 1800cc
Joined
·
4 Posts
So here is what I learned about motors from this site. I wanted to post a quick reference so newbs (like myself) do not have to sort through the sticky page.

When looking for a forklift motor:
Get a series wound motor because they have very high torque and handle abuse (over volting) a lot better.
Know the difference between a Spex motor and a Series wound.
When dealing with series wound forklift motors go for higher voltage. (36V may require advanced timing.)
Hp does not directly represent torque (although it does have a factor in its equation).
Get a class H insulation if possible (makes your motor last longer)
Get a motor around 150lbs (Wouldn't risk a motor that's too light, it won't have the oomph you need. a few extra pounds is A-o.k. but a significant amount of extra pounds limits your range)
Get one with a male shaft
A keyed shaft is easier to work with but you can still work with a spline shaft
Try and get the coupler that goes on to your motor when you buy it/rip it out (saves you $$ and time)
When looking for a different motor:
Ac is not the way to go for your first conversion (or do i just have low expectations of myself?)
You can tell if a motor is AC if it is a 1 phase or 3 phase motor
Pancake motors are usually not good candidates for car conversions. (Yeah you saw the one on ebay. They overheat easily)
Golfcart motors are seldom powerful enough for a conversion
Motors specifically made for EV conversions are the best but its gonna cost you.
You do have to look at many factor such as volts, amps (which gets you Hp). Torque is nice to know. Continuous Hp. So many factors!!!
If there is any more helpful hints I'll be happy to add them

thanks, that was a mouth full. i thinking seriously converting my 1971 MG BGT 1800cc. it's got great power and tuned per MG spec. I could sell the original motor and keep the tranny for the conversion. do you know where to get the adapter plate to mate the E-motor to the MGB tranny or make an aluminum for light weignt? what is the best and high effeciency lithium ion phosphate battery, the cost, number of cell per pack? i'm just tire of paying high gas price. what would be an ideal budget for this venture?
 

· Administrator
Joined
·
6,613 Posts
thanks, that was a mouth full. i thinking seriously converting my 1971 MG BGT 1800cc. it's got great power and tuned per MG spec. I could sell the original motor and keep the tranny for the conversion. do you know where to get the adapter plate to mate the E-motor to the MGB tranny or make an aluminum for light weignt? what is the best and high effeciency lithium ion phosphate battery, the cost, number of cell per pack? i'm just tire of paying high gas price. what would be an ideal budget for this venture?
First and most important with any conversion - what range do you need?

Range - and hence battery size required sets the rest of the needs
 

· Registered
1982 Datsun 720
Joined
·
28 Posts
Dunno if you wanna say where you are, but... the thing about forklifts is literally everywhere in the industrial world has to have a place that services them in just about every city over 50,000. Everyone needs forklifts, everyone needs a place to fix them.

I have a sweetheart deal with mine. They'll move a forklift up on jackstands for me, outside the gate, and I can come help myself to it at night over a week or two, gutting what I want off it. And they don't charge me for anything I take. And I can occasionally borrow tools when there's something I don't have big enough tools to tear up. And they leave me deserts sometimes. The tradeoff is I show them pictures of what I'm working on.
Dude, Where are you located and if you're not too far will you sell me a motor?!
I'm in the Los Angeles, CA area and am having trouble locating one. When I call repair shops or forklift scrappers they all seem confused and say something like "No, we repair motors, we don't sell motors" like I'm crazy for asking.

I mean... mechanics repair engines but most of them still have one or two lying around that they'd sell if you asked
 

· Registered
Joined
·
5,359 Posts
LA has a Sanford and Son ecosystem of scavengers, so a repair shop is probably a bad place to look.

Damien, Matt, and Duncan let out a can of worms, a Heisenberg Uncertainty Principle perversion, by stating publicly "you can get a forklift motor for free", so if there were any, they'd be rare as hens teeth these days, imo.

With copper prices through the roof, and iron not exactly cheap either, it'll be a rare pack rat that has one that didn't go to the scrapman, especially since modern day forklifts usually use non-brushed motors, so there's no point keeping it around.

That means you need to buy a Hyper9, FB-4001, or similar and drop the fantasy of doing an EV conversion for $1000. You can still keep looking, you might be the exception, but anything in stock is no longer cheap.
 

· Registered
Joined
·
413 Posts
Maybe try Bakersfield, Go to the shops with money in hand if you have been getting no where with calling. Which it sounds like. Ask the forklift repairmen if they know of anyone that has an old DC forklift motor. I understand The asking in person money in hand works sometimes.
When I call repair shops or forklift scrappers they all seem confused and say something like "No, we repair motors, we don't sell motors" like I'm crazy for asking.
Write down what you are trying to do, maybe people will understand.
keep an eye out for deals craigslist, bulletin board, friends, family, co workers etc
later floyd
 

· Registered
1982 Datsun 720
Joined
·
28 Posts
Maybe try Bakersfield, Go to the shops with money in hand if you have been getting no where with calling. Which it sounds like. Ask the forklift repairmen if they know of anyone that has an old DC forklift motor. I understand The asking in person money in hand works sometimes.

Write down what you are trying to do, maybe people will understand.
keep an eye out for deals craigslist, bulletin board, friends, family, co workers etc
later floyd
All good advice, thanks!
 

· Administrator
Joined
·
1,761 Posts
Dude, Where are you located and if you're not too far will you sell me a motor?!
Canada.

So, no.

I'm in the Los Angeles, CA area and am having trouble locating one. When I call repair shops or forklift scrappers they all seem confused and say something like "No, we repair motors, we don't sell motors" like I'm crazy for asking.
Yeah, motor rewinding places aren't somewhere I'd suggest. They don't have motors in inventory that I've ever seen (though I haven't seen many).

...

Maybe try Bakersfield
So, problem with Bakersfield, and Southern California in general, with free, is Mexicans.

Where I'm from, everyone is generally well-off, well-educated, and there's not a lot of poverty. So there's not a large culture of squeezing every drop of value out of something. There's a high amount of waste.

For example, around here you can fully furnish an apartment, every day, for free, with good stuff, just from Freecycle or free facebook or our Craigslist equivalent. People here throw away appliances not because they're broken, but because they're the wrong color. Perfectly working, expensive items have negative value because people just want them gone. Ditto for couches, kitchen tables, etc. Back in the day, most of my friends bought a new computer every year. If you were okay with a 1-year old computer, they were just going straight to a landfill.

That doesn't exist in places with poverty, or a lot of illegal immigrants that can't participate in the formal economy, or where a large portion of the population grew up with very little. People don't just leave money on the table like that. If there's $20 to be made, someone's out there making that $20.

When I lived in SoCal (and Bakersfield), there was basically nothing anywhere for free. For a scrounger, that upset me.

The flip side of this, is that there is a heavy underground scrapper market for everything down there. Up here you'd have no choice of buying something really cheap, because it's not worth anyone's time to administer selling it. You can even ask and offer to take it away for free, and most people don't even want the hassle. We have giant scrap metal dumpsters here, that people PAY to have someone haul away for them, as if free metal is a waste product (because, it is). But down there (and, in worse parts of town up here I'm sure), if you just ask around, you'll get hookups for everything. If you put out to the right people that you want a forklift motor, and you'll pay $50 over scrap value for it... the hunt is on. They'll find you one. Zero chance of that ever happening up here. You'll have to be where scrappers go though. Places that might throw away scrap metal perhaps, or scrapyards itself, if they have a posting board.

You have almost no chance of getting one for free, but you have a great chance of there actually being a market for "slightly above scrap value components".

Also, one thing perhaps I, and perhaps others neglect to consider... is that some of us are just socially charismatic and persuasive, in unconventional ways. This isn't a cocktail mingle event, but lots of people on the bluer collar of town have their equivalent of it, and, knowing how to read people, inspire them to go a little out of their way and a little ways around what their lawyer might say, to find common ground about what parts of your project they find sympathy with and excitement in, is a huge part of getting this done. I talked my way into every single recycled tool battery in my half of the province being put in a bin with my name and number on it. It's probably not reasonable to suggest that because I was persuasive, that anyone else could be in a similar way.

A common thing people say is to just show up with a case of beer and talk to the guys in the back. They'll eliminate what you want from the waste stream without the front office having to approve liability and why the sales team isn't involved. I don't really even know how to do that, or to start that conversation. Do I bring the beer with me? Do I leave it in the car? Do I drop it off later? Won't you just get run off the property if you show up at the back where the maintennance guys are? And yet that's probably the most common piece of advice for blue collar currency for uncommon requests. The guys who can work that into conversation are a whole other tier above me. I have a feeling this power arrives when your beard turns grey.
 

· Registered
Joined
·
195 Posts
I haven't posted on here in a long time, but you caught my attention so I think I'll chime in. I agree with what matt said, but in addition to it, I'll throw out a couple of thoughts to consider. I repair forklifts for a living, have for almost 18 years. We've never once sold a used motor. I have however acquired 4 complete forklifts over the years for cheap or free, and could have had more if I'd wanted to. It's all about being in the right place at the right time. You would probably have more success finding a complete dead forklift, stripping out what you want and selling the rest for scrap. You won't get answers at the front counter. Your best to find a field tech, or even a sales guy. What you ask is if they know of someone who has a junk forklift that that's too expensive to fix. BUT,1) it probably still won't be free and it may require more work than you want to put in. You'll likely have additional costs attached for transport as well, plus there are not really that many good candidates for suitable motors left around IMO.
2) the other thing you need to consider is that cheap DC controllers have become even more rare than motors and you may not have a way to use one, even if you can find one. I've got 2 good motors sitting in my garage that I wanted to use for a conversion for a long time, but now the options for controllers are gone, unless you are an electronics tech and can build you own. We're a little late to the party I'm afraid. The majority have moved on to AC, which is better tech for sure. and with lots of EV's in wrecking yards now, might not be any more expensive.
I still have a soft spot for DC, but mostly because I hate to throw anything away that I already have.
 

· Registered
Joined
·
5,359 Posts
And good luck getting parts if you decide to build one.

I found a few microcontrollers on promise of delivery in a couple of months, spent the money on an order, and a day later they pushed the delivery to the end of the year. This evg I sent a cancelation notice and requested a full refund, cuz Homey don't play dat.

Even simple things like voltage regulator chips are Unobtanium, so if you decide to build something, fat chance you'll find the parts for it. If you can make a decent lunch with whatever is in the refrigerator, like I tried to do with the micros, you still get screwed.

They laid off all the good people a few years ago and this components mess is partly because the lunatics and bean counters have been running the insane asylum ever since. And the Chinese appear to be hoarding every part they can get their mitts on.

Make sure you have all the pieces of the puzzle...
 

· Registered
Joined
·
2,056 Posts
Bakersfield is a petroleum/ oil service economy that has warehouses. The seedier parts of town like oildale, buttonwillow, Arvin, or Lamont may still have scrapyards but like Remy said, stuff has too much value to just take to the dump for free. At 200+ lbs, a 13"motor has scrap value of beer and the gas to get there. There's a forklift recycle place in Stead, but they don't do electric. We have a motor rebuilder here in Reno, but their scrap pile is full price and they want $$$$ to rebuild, $$$$$$$ to rewind and 6months to get around to it if they like you. That's only good if you have an antique thing that generates you a pot load of Ben Franklins to pay for the repair.
 
161 - 174 of 174 Posts
Top