Electric 6 wheeler?

[JRP3]

Thanks, I'm learning as I go so any information is useful. Trying to decide on the motor mount, I was thinking of maybe using the stock mounting plate with the rubber mounts to take some of the torque loads on the drive line, but since I'm using chain and sprockets instead of clutches and a belt I'm thinking the flex might allow the chain to mis-align and fly off. The electric motor won't have any vibration to dampen anyway so I'll probably just go with hard mounting.

[hdble]

I believe I would hard mount it, you don't want your chain tension to change.
With rubber mounts your motor would be able to twist a little bit, causing the sprocket to wear.

Are you still going to run through the T-20?

[JRP3]

Yeah, hard mounting it is. Yup, T-20 will be used. Now I have to figure what ratio I want to use. I just checked the T-20 and it looks like it's 6:1, with a total 11:1 including the tires. I think I can go with a pretty close ratio between the motor and the T-20, which would allow me to swap the gears around for a quick gear change if I wanted.

[hdble]

Yeah, hard mounting it is. Yup, T-20 will be used. Now I have to figure what ratio I want to use. I just checked the T-20 and it looks like it's 6:1, with a total 11:1 including the tires. I think I can go with a pretty close ratio between the motor and the T-20, which would allow me to swap the gears around for a quick gear change if I wanted.

That would be good, more speed, or more torque.
I guess I am still curious about battery charge life, I guess it depends alot on what your doing. Should be cool!

[JRP3]

Run time is always the thing with EV's. More time = more money. With my projected setup I'm hoping for around a half an hour, which for my needs should be plenty and won't break the bank. I'm not ready to drop 3-4 grand worth of lithums in this thing, but maybe in a few years they will be more affordable as the prices continue to drop.

[JRP3]

OK I won't be swapping gears since not surprisingly the shaft on the T-20 and the motor aren't the same size Not a big deal, I could just get 2 sets if I feel the need to change ratios. Still trying to figure out what I want, leaning towards a 1.5:1 ratio between the motor and the T-20 which would give me a 16.4:1 final ratio. That should get me close to a 22 mph top speed at 6000 motor RPM's and give me plenty of low end power without overheating the motor. Now, what size sprockets do I want to use to get that 1.5:1 ratio? Probably the smallest possible without causing problems, but how small is too small? I assume I'll use #50 chain, non-o-ring, since I think that's what's on the rest of the machine? Any good places for hardened sprockets?

[hdble]

Try Mcmaster-carr.com
I thought you would get a few hours out of a charge on your batteries,my golf cart I run around the yard on pull trailers etc., lasts several weeks on a charge,36 volt,6 6volt deep cycle.

[JRP3]

Your 6 six volt deep cycle batteries are probably 200 amp hour batteries, the 4 twelve volts I'll be running will be 70-100 amp hour batteries. They'll be able to put out more current over a shorter time and weigh less but won't carry a charge as long. Your golf cart also isn't trying to turn 6 off road balloon tires. I may get more than half an hour of run time which would be great but I'm trying to be conservative so I won't be disappointed.

[Beeman]

OK I won't be swapping gears since not surprisingly the shaft on the T-20 and the motor aren't the same size Not a big deal, I could just get 2 sets if I feel the need to change ratios. Still trying to figure out what I want, leaning towards a 1.5:1 ratio between the motor and the T-20 which would give me a 16.4:1 final ratio. That should get me close to a 22 mph top speed at 6000 motor RPM's and give me plenty of low end power without overheating the motor. Now, what size sprockets do I want to use to get that 1.5:1 ratio? Probably the smallest possible without causing problems, but how small is too small? I assume I'll use #50 chain, non-o-ring, since I think that's what's on the rest of the machine? Any good places for hardened sprockets?

I've heard somewhere that it is optimal to have at least 9 teeth touching the chain at any given time (not all fully neshed, just touching), but this was from an industrial environment.

The link on this site seems to be down, but there is a PDF of ANSI HP ratings for roller chain from the American Chain Association .

-Beeman

[hdble]

Your 6 six volt deep cycle batteries are probably 200 amp hour batteries, the 4 twelve volts I'll be running will be 70-100 amp hour batteries. They'll be able to put out more current over a shorter time and weigh less but won't carry a charge as long. Your golf cart also isn't trying to turn 6 off road balloon tires. I may get more than half an hour of run time which would be great but I'm trying to be conservative so I won't be disappointed.

It was a simple comparison,my golf cart sits on 25" tires,and weighs 178# more than my Attex,

[JRP3]

It was a simple comparison,my golf cart sits on 25" tires,and weighs 178# more than my Attex,

Of course I'll be adding 240lbs of batteries to the Attex, and I'll bet the rolling resistance of 6 aired down off road tires is much higher than your 25's. Believe me I hope my range turns out closer to yours but I've got a lot going against me.

[JRP3]

Looks as if I can take my gearing cues from what's already on the Attex. The drive gears on the T-20 look to be around 14 tooth gears, which is just what I was thinking of using, (14 and 22), to give me my 1.5 ratio, approximately. Got 2 of my motor brackets done, mounted to the top 4 mounting holes on the T-20, very convenient. I may tie them into one of the center rib bolts on the T-20 as well, but I figure if the 4 bottom bolts are enough to keep the T-20 attached to the frame the top 4 should keep the motor stuck to the T-20.

[Wahoo]

A Hybrid AATV Might Have Real Possibilities

Hi guys, I'm new to the forum and I just want to say I've been really impressed with the helpfulness and mutual respect I've seen displayed here. Not all forums are like this.

I've been researching the market to purchase my first AATV. After reading your comments on the different AATV's out there I've come to the personal conclusion that AATV enthusiasts have at least two major issues with the AATV's currently on the new or used markets. It seems the maintenance and reliability of AATV drive trains is one issue and the desire by many for more speed is another. The speed issue is apparently due, in part, to the difficulty in having a suspension that will allow one to maintain control at higher speeds over rough terrain and still have a water tight, swimming, chassis and not so much an issue of cramming more power into the vehicle. I've been watching Whipper's answer to that one with great interest. The maintenance and reliability issues are apparently the nature of the beast. I recently spoke to a former AATV dealer in Houston who now sells Rhinos, Kawasaki's and Kubotas and he warned me that while they were great fun and very useful, I should be prepared to work on them constantly.
It occurs to me that anything that gets beat up in the woods, trails and mud bogs will require periodic maintenance and I have no illusions about that. But, I think a Hybrid AATV might address this issue to some degree. I think properly protected electric motors, a bank of high efficiency batteries, and a small diesel or gas generator could be engineered in the the current AATV form in a way that could greatly simplify the drive train, improve reliability and provide great range. And having a robust electrical system on board would allow you to easily add a trolling motor (or two) to assist with deep water. I'm really interested in exploring the possibilities of a hybrid AATV and I think I'm ready to devote some time, money and elbow grease to produce a good one.

[JRP3]

There are two problems involved in a hybrid AATV.
1. You are essentially using two separate systems and doubling the complexity and the cost.

2. There isn't a lot of room in an AATV, except some of the larger ones, so you compromise your battery range by taking up space with the ICE components and you add weight that has to be hauled around all the time when it's really not needed most of the time.

The great thing about electric is the low maintenance, why add it back in with a generator?
Attex claimed 4 hours of run time in 1970 with golf cart batteries, how much range do you really need?

I think the best way to go would be with two reversible motors capable of regenerative braking and lithium ion batteries for increased range. This removes the transmission from the equation which further simplifies they whole system. Lithiums are coming down in price to make this feasible.

[Wahoo]

There are two problems involved in a hybrid AATV.
1. You are essentially using two separate systems and doubling the complexity and the cost.

2. There isn't a lot of room in an AATV, except some of the larger ones, so you compromise your battery range by taking up space with the ICE components and you add weight that has to be hauled around all the time when it's really not needed most of the time.

The great thing about electric is the low maintenance, why add it back in with a generator?
Attex claimed 4 hours of run time in 1970 with golf cart batteries, how much range do you really need?

I think the best way to go would be with two reversible motors capable of regenerative braking and lithium ion batteries for increased range. This removes the transmission from the equation which further simplifies they whole system. Lithiums are coming down in price to make this feasible.

Good points but, I'm wanting a vehicle I can truly take anywhere. One capable of an expedition or week long trail ride. I would welcome redundant motors, probably more than just two. And I think I'd like the generator section to be "modularized" so that people like yourself who don't require a vehicle to go into the Alaskan wilds or East Texas swamps could simply treat it like a golf cart and plug in overnight. The generator module could be mounted or demounted as required. That would give you the flexibility of easily offering a diesel or gas option. And I agree with you that I would like to design out the T-20 transmission, most of the chains and linkages and use "fly by wire" and control everything with joysticks. I would modularize everything for easy maintenance. A joystick goes bad? Pop four turn locks and put in a new one. A drive motor goes bad? Keep running on the remaining motors. Make the mounts easy to access so swapping a motor isn't a nightmare. I'd like the flexibility to run on two motors to save energy or kick in up to six (one per wheel) for full power. Maybe it could be designed for up to six but you can buy one larger motor per side and link the axles if you didn't want the redundancy.

What do you think would be a reasonable speed to expect or design to?
What about water speed?