Author Topic: push-trailer update  (Read 29618 times)

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REdiculous

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push-trailer update
« on: April 12, 2010, 02:00:00 AM »
I finally almost got it...

I needed another big gear reduction on my trailer so I made a 'chainring to freewheel sprocket adapter' out of a steel pan I'd tossed out in the shop 10yrs ago. As soon as I opened the door to the shop I saw it in the far corner laying on top of the old dishes, kind of poking out just begging for a new life. A few minutes with a pen, a drill-press, a saw and a file and it was done.  8)

With the 48t sprocket on the wheel the trailer is geared for a top speed of 30mph. Too bad I can't supply the power needed for that..yet...so I was thinking about getting a larger chainring for the wheel. My real goal is closer to 20mph anyway since that's what the local law allows and it'll take too much power to go much faster. If I put a 60t sprocket on the wheel instead then my max speed will be closer to 23mph.

I still need to get another 12v, 20ah battery and a 1kw inverter. Then I can drive my motor at up to 900w, limited by the controller (and capacity) and I might actually be able to achieve the speed it's geared for. If I can keep it from throwing chains that is...

..which I'm having trouble with. The chain on the motor side came off right away so I made a new one from a different/newer chain that was slightly shorter/tighter for the same number of links and it seemed to stay on a lot better. So then it threw the chain on the other side. Then someone rang the dinner bell..heh. More later and I'll get pics soon-ish.

Have a good one! :)
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Bruce S

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Re: push-trailer update
« Reply #1 on: April 12, 2010, 11:52:03 AM »
RE;
 the biggest problem we had with the pedal & hub-motor trike was the chain and it's derailing system. The chain is really touchy and must be as true and square to the sprockets as possible.
 
Is the steel pan smiling now :-)? making the happy I'm loved happy dance for you <LOL>.

Some of the older APC 1500 watt UPS's have the 12V18Ahr batteries in them, most get toasted by the charger cooking them, but most are still in usable shape for testing and tweaking.
Have fun!!
Bruce S
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REdiculous

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Re: push-trailer update
« Reply #2 on: April 12, 2010, 08:55:16 PM »
Man I wish I had a trike! I prefer tadpole but either is fun. I can't imagine having gears through a normal derailleur though...internal 3+speed hub ok.

The pan-dapter is working great and it seems to be running true. While bench testing it, if I don't tilt the trailer in either direction too far then both chains will stay on at full speed, it just the length of the chain that's slightly off. In practice it tilts so I just need a way to adjust the tension. I'll probably use rollerblade wheels..I dunno...

I've actually been thinking it's time to give up the current setup..instead I could use one of those hub motors and be done with it. I'd want a new trailer frame but that would be really easy to put together. Then I could start thinking about building a tadpole to put the treadmill parts on...where the potential might see some real use.

But first I'm gonna try to get this working anyway..so that means chain tensioners or some kind or guides on both sides. It'll only make the transmission losses worse, but if I can get enough power through the motor it'll work for a few minutes anyway.

On a new machine, if I made another adapter I might be able to use a steel freewheel hub (no spokes/rim) instead of the backwards crank design...that would make it easier to make a mounting since I could use slots like the rear of a bike. Then I could adjust the tension on a fixed-mounted motor too. anyway...heh...live an learn...that's what this was for. :)
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REdiculous

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Re: push-trailer update
« Reply #3 on: April 14, 2010, 09:17:15 PM »
If the attachment works then it'll show my bike and the little trailer I made today. I added a luggage rack to it after the pic was taken but I'm not sure I like it. I'll reserve judgement until it has a net bottom on it though.

I think if I can find a cheap hub motor I'm gonna go that way since I could probably just add it to this trailer (along w/ lead weights). yup yup
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Bruce S

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Re: push-trailer update
« Reply #4 on: April 15, 2010, 09:29:27 AM »
If the attachment works then it'll show my bike and the little trailer I made today. I added a luggage rack to it after the pic was taken but I'm not sure I like it. I'll reserve judgement until it has a net bottom on it though.

I think if I can find a cheap hub motor I'm gonna go that way since I could probably just add it to this trailer (along w/ lead weights). yup yup

RE: The bike looks quite comfortable :).  I'm a little worried about where the neck attachment is, but it maybe the pic doesn't show close enough detail.
A Hub motor as a pusher type should do nicely , and I would think a kit that come with a controller would do very nicely. Goldenmotor people have a 72V 5k brushless unit that I'm currently drooling over  ;D.

Li-based  batteries would keep the weight issue off the trailer, but you could source SLA and have them mounted to a nice low center of gravity and still have some pocket change left over. They would work until you settled on a design then jump to other battery types.
How well does it handle when turning corners?

Looking good!
Bruce S
 
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REdiculous

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Re: push-trailer update
« Reply #5 on: April 15, 2010, 12:27:19 PM »
I call it my "Hardly Davidstein"..heh. It is pretty comfy, just not very pretty.  ;)

I think w/ a trailer this size the lack of weight could be an issue if turned into a pusher. I think I'll want to use SLAs so that the trailer doesn't bounce all over the place. I doubt I'll ever be able to afford Li batts anyway.

This one handles corners fine but a bit more of an angle on the neck might be better. I'm not good at eyeballing angles but it looks like the neck is around 2 or 3 degrees on level ground...closer to 5° might be best.

I didn't have an extra hand at the time so the attachment just shows a full left turn at the hitch...there may be enough detail left that you can see....something. :)
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Bruce S

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Re: push-trailer update
« Reply #6 on: April 15, 2010, 01:02:16 PM »
RE;
 Now it looks beefier than the previous picture.

Weight could be a problem, could get bouncy.

Have fun with it:)
Bruce S
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REdiculous

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Re: push-trailer update
« Reply #7 on: April 15, 2010, 04:58:27 PM »
I think it's still kind of hard to see...

On the back of the bike I added 'lift outs'. The red tube that the neck is holding has 2 rollerblade bearings on either side so it rotates nicely and should take a decent load. I cut the tube short enough so that I could add an inner set of thin nuts on either side so that it all stays together like a little wheel...and it bolts to the bike like one.

I actually inherited the little scooter front end and have been trying to find a good use for it for years. The threaded tube extending up towards where the handle bars would be was too long so I cut the excess off that and took it to the grinder. The little forks sticking up made me mad so I got rid of those w/ bolt cutters real quick and smoothed the edges there too.

As an adapter between the scooter front end and the fork holding the wheel is the seat-tube from my kid's old bike. It fit snug into the scooter side and I ended up pounding it into the forks. I marked the holes and drilled the seat-tube and then bolted it to the scooter front. Since I had used a small sledge hammer to pound the seat-tube into the forks I didn't bother adding a bolt through that..I may go back and add one or just weld the two together in a couple places.

I said I added a luggage rack earlier but it's really just a frame for one. It's sitting a bit too high for a flat surface which is why I mentioned a net..it's a couple inches above the tire. I tested it w/ a piece of half-wet fiberboard on top (guessing 20lbs) and of course it was too hard to control. I may lower the rack and add a flat surface anyway..I'll just have to cut a place for the wheel to poke through.

I dunno..as one of those "what can I make in under an hour?" type projects I think it came out nice. 8)
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Bruce S

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Re: push-trailer update
« Reply #8 on: April 16, 2010, 11:23:58 AM »
In under an hour!? that's good! I would've had to have 2 beers talk to neighbor  about bringing over welder have beers with them then get it going :).

Sure is fun to build stuff, plus wifey likes the idea of clearing up yard again :p

Cheers
Bruce S
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REdiculous

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Re: push-trailer update
« Reply #9 on: April 16, 2010, 12:48:49 PM »
yeah, getting points for cleaning up the yard is nice.  8)
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REdiculous

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Re: push-trailer update
« Reply #10 on: April 17, 2010, 04:17:52 PM »
So yesterday I made the frame slightly longer by pulling the seat-tube out of the scooter front-end a little which increased the angle of the neck enough that my turn radius is completely unaffected now. I also started on the battery holder which is basically done too...I may end up redoing it later since this one only holds a single and I'd like to have at least 2.

Oh, I got a sheet of polycarb I think I'm gonna use on the luggage rack. I lowered the rack as far as possible so it's now about an inch below the level of the seat on the bike. Still about 21" off the ground so heavy stuff could still be a problem but a 12-pack or 2 should be fine.

Now I'm on the hunt for a decent 1HP-ish 90v DC motor. If I can find a 1750rpm motor then I could gear it in one step which would be nice. I kinda wish I knew more about this...
http://www.surpluscenter.com/item.asp?item=5-1732&catname=electric

Is it 90w or 450w? If it's 450w peak, think it'll handle 375w continuous?

If it's strong enough, that would be a good option since 500rpm is 30mph with my wheel...again, one (even easier) step. That and I could use the controller I already have. I dunno...I'll get there eventually. :)
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REdiculous

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Re: push-trailer update
« Reply #11 on: April 23, 2010, 04:44:03 PM »
I put my 10yr old on this trailer and went down a bit of a hill. Even with almost 100lbs of trailer it was fine....fun even! ;D

Over the next week I'm gonna try to get the motor on this one...we'll see how that goes. All in good fun!


« Last Edit: September 23, 2010, 07:10:03 PM by kurt »
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REdiculous

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Re: push-trailer update
« Reply #12 on: April 30, 2010, 01:27:40 AM »
Still gettin' there...

I wrapped the sides of the battery w/ a piece I cut from a plastic barrel. I left the foam between the top of the battery and the adjustable frame member since I wanted some cushion there. The plastic should protect the battery pretty well I hope.

A big step was extending the wires (maybe not far enough) for the little control box. Now I can have it on my lap when I test it..yay! It's still in the cardboard box it came in so not good for long hot runs but fine for testing.

Another step was cutting the up-tube (?) off the yellow forks. I still want to cut a few inches off the forks since there's no wheel, and I should be able to add better dropouts so that I have more room for adjustment while I'm doing that.

Oh, I made the geared hub today too. The aluminum pan turned sprocket adapter is a little wonky but not terrible. I think the pan got dented along the way and the holes came out somewhat skewed and off center. Since it's secured to the hub I'll probably bore the holes out some so that I have some room to center the sprocket better. I had to pound it flat before I put it on the hub..grr..I hate aluminum now. I totally wasted a pan too..aluminum taco.

The 16t sprocket went on the other side of the hub snugly and I welded it in 3 places..done in 10mins. It turns out I should've flipped the 16t sprocket since it would've lined up better. I need to replace the lock nut on that side of the hub to recover from that goof...or I can fix it when I mod the forks.

Anyway, I loaded it all up and drove down to the street and it pushed me about 3 blocks before I was going too fast and the chains popped off. I guess I'm only a little step closer..oh well. I'm sure I'll get the chain alignment ironed out and get a new inverter in a few days...should be fun.

I like that it doesn't need a kickstand..heh..silly, but cool. 8)



« Last Edit: September 23, 2010, 07:10:32 PM by kurt »
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REdiculous

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Re: push-trailer update
« Reply #13 on: May 01, 2010, 12:52:50 AM »
I was playing with the chain alignment today and I think I got it pretty well nailed down...actually it was the lag bolt that did it but whatever. The motor still bobs up and down because the sprocket on the hub is still off but the chains stay on despite that and the gravel road..win. ;D

I'm still trying to decide on the inverter I want tho. Should I try 500w, 800w or should I go for 1kw or more?

Is the inverter's efficiency based on the load? More load = more efficient?

There's a 500w inverter on sale locally that looks tempting but I'm sure I want peaks higher than that...is that the trade-off?..it's just the peaks that are efficient? Would love to hear your thoughts here. tia
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Bruce S

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Re: push-trailer update
« Reply #14 on: May 03, 2010, 09:11:58 AM »
RE;
  The inverter will depend on your usage. The 500 watt will be too low since the motor is probably of a wattage were you could over heat that inverter when you try to go up hills or have an extra heavy load.

 I don't have the information you posted about the motor voltage and current draw readily , however the 1k unit, IF it is not too much more in cost, will allow you to have room for expansion or heavier loading especially since you are looking to up the motor size.

It is of course a trade off, sine the 1K unit will also require more idle power usage, but it will allow you to up-size the motor.
Having fun is good :)

Cheers
Bruce S
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REdiculous

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Re: push-trailer update
« Reply #15 on: May 03, 2010, 01:25:38 PM »
I put my check in the bank on Saturday and it's still not available yet..grr...maybe by lunch...

I'm sure you're right, 500w isn't enough. I think I'm done worrying so much about inverter efficiency..1kw it is. Maybe 1.5kw since that's what the controller can handle...

Think I can cut the lights and manually control the fan in the inverter to increase the efficiency? I'd have to watch the temp and it'd void any warranty but..maybe?

The other thing I was curious about...is it possible to run one load off of 2 inverters? have a good one! :)
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Bruce S

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Re: push-trailer update
« Reply #16 on: May 03, 2010, 04:04:11 PM »

The other thing I was curious about...is it possible to run one load off of 2 inverters? have a good one! :)
RE;
  Honestly I would be very worried about trying to sync the two inverters so they run as 1.
Plus the extra headache of making sure they are load balanced is ...yuck-O for me.
For my money I would go with a single inverter and sleep better.

Cheers!!
Bruce S

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REdiculous

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Re: push-trailer update
« Reply #17 on: May 04, 2010, 01:48:27 PM »
So I picked up a Power Drive 1kw inverter this morning for $80...

It's rated for an hour continuous at 1000w and draws 0.5a idle. When the inverter is off there's no drain..cool! Surges to 2kw. It has 2 sockets, a usb port and ethernet jack for remote on/off switch. On the front it has a little panel that switches between showing the battery voltage and the output in watts/kilowatts..very handy.

Sadly it doesn't work any better than the 350w inverter yet. It's actually worse since I can't get smooth operation at all. It's probably the battery though...

When I turned the inverter on it shows the battery as being 12.5v and I know the battery was fully charged. It was charged over night and I only disconnected the charger 2 minutes before installing the inverter so I was expecting to see 14v. I guess I'll have to check it w/ a meter to make sure the battery isn't dying already.

I'm sure I'm expecting too much from the battery now..gotta get more. :)
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Bruce S

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Re: push-trailer update
« Reply #18 on: May 04, 2010, 02:19:12 PM »
RE;
 If the battery was just taken off the charger and it read 12.5V then I'm thinking either the battery is starting to wane. Perhaps the charger didn't fully charge it?
I agree the battery should be showing much higher than the 12.5 :(.

Best of luck.
Bruce S
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REdiculous

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Re: push-trailer update
« Reply #19 on: May 04, 2010, 03:16:00 PM »
I checked w/ a meter and it's 12.56v, just like the inverter said.

I just remembered tho..maybe it's the charger. I forgot that the shop leaks in a couple places and the charger got soaked a few weeks ago (unplugged). The case is well sealed but not waterproof so I let it dry for about a week before plugging it in and it seemed to work. I've stuck keyboards in the dishwasher before and got good results...it just has to be dry before you plug it in.

I was still using the battery and charger to test my chain alignment and whatnot. After a short run the charger would see that the battery wasn't charged and would appear to charge it. When I'd reconnect the charger to the already-charged battery the charger would show that it was full too. I never checked the battery voltage before the charger got wet but the battery is barely 3mo old and I didn't really abuse it...or so I thought.

Think the charger just decided to stop at 12.56v for some reason?

edit; I saw it charge up to 13.8v and then it started to creep down even though the charger was on. That seems kinda weird to me but this is my first system so I have little to compare to. hrmm.

Either way it sucks..darn it. >:(
« Last Edit: May 04, 2010, 03:39:52 PM by REdiculous »
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TomW

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Re: push-trailer update
« Reply #20 on: May 04, 2010, 03:43:11 PM »


Think the charger just decided to stop at 12.56v for some reason?

Either way it sucks..darn it. >:(

Why not try a GHurd special charging arrangement?

I think he patented it.

Charge the thing with your road vehicle and some jumper cables. Should drag it up around 14 volts easy in a reasonable time.

Just another angle not involving one of those silly "smart" chargers they seem to sell these days. At least get you back to testing quickly!

Tom

Bruce S

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Re: push-trailer update
« Reply #21 on: May 04, 2010, 05:04:24 PM »
I checked w/ a meter and it's 12.56v, just like the inverter said.

Think the charger just decided to stop at 12.56v for some reason?

edit; I saw it charge up to 13.8v and then it started to creep down even though the charger was on. That seems kinda weird to me but this is my first system so I have little to compare to. hrmm.

Either way it sucks..darn it. >:(
RE, it does suck, TomW has the right idea :).
If it's anywhere near similar to one I looked into "fixing" that was a freebie and more trash than anything  :-\... anyway it looked as if there was a type of comparator circuit in there that was trying to be the brains.
A comparator circuit is a cool little idea but if it gets out of whack then its worthless. My thinking would be the charger has damage to a cap or chip.

Try this just for testing sake, As TomW said grab a safe set of jumper cables, hook it to car battery while car is running, hook other end to battery that is connected to inverter, turn on inverter and see what the voltage reads, and if time is on-hand get the inverter a tes too. Should be better outcome.
Cheapo HF trickle charger on sale for $9USD and a $1 24hr timer from dollar store can be your friend :)

Bruce S




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REdiculous

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Re: push-trailer update
« Reply #22 on: May 04, 2010, 06:13:17 PM »
I'm not sure I wanna do that more than once (gas..) but will give it a shot...thanks. :)
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REdiculous

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Re: push-trailer update
« Reply #23 on: May 04, 2010, 07:12:40 PM »
It turns out that the old inverter was hiding an issue I hadn't thought about before..purely inductive loads. The little inverter didn't seem to mind but the new one sure does. The simple solution is to run an incandescent light as well.

Off to cause some more trouble...later.
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REdiculous

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Re: push-trailer update
« Reply #24 on: May 04, 2010, 11:54:30 PM »
With the battery charged back up and the bulb trick figured out it's back to chain alignment. I haven't tried it on the street yet but on gravel it's dropping the chains within 50ft of starting out. I think I'm gonna cut the rear dropouts off of a bike tomorrow and weld them to the forks..that way I should be able to get the chains lined up a lot better.

There's a ton of power though, so at least there's that...I had the wheel spinnin' through a grassy spot which was kinda cool. later
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zap

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Re: push-trailer update
« Reply #25 on: May 05, 2010, 10:42:31 AM »
...I haven't tried it on the street yet but on gravel it's dropping the chains within 50ft of starting out.
...I had the wheel spinnin' through a grassy spot which was kinda cool.
Sounds as though you're getting it figured out.
If the liquor store is next door... or as long as the 4th of July parade route is short enough... I'd say you have a winner! ;)

I have a feeling the inductive load trick would have eluded me for a lot longer. :-\

REdiculous

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Re: push-trailer update
« Reply #26 on: May 05, 2010, 12:29:24 PM »
Quote
If the liquor store is next door... or as long as the 4th of July parade route is short enough... I'd say you have a winner!

I have a feeling the inductive load trick would have eluded me for a lot longer.

Unfortunately, the liquor store is at least 18 miles away but a parade might be do-able since it's so slow and on pavement. lol

Adding the bulb was just something to try. I'm pretty sure I've been at this for 2 months by now so it eluded me for awhile too...oh well. Have a good one.
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REdiculous

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Re: push-trailer update
« Reply #27 on: May 07, 2010, 04:32:09 AM »
My whole body is sore from working on it, mostly my hands, but I think I'm really (really!) close now. It pushed me about half a mile at about 15mph (gut feeling..no spedo yet) on fairly level ground with a good head wind and no real tucking on my part. No pedal input either..total weight was about 220lbs. With the 60w bulb on too since I was testing the mechanics more than anything. I have some AC->DC bricks I can use to try a smaller light, I just haven't gotten that far yet.

When I turned around I guess the new tensioner I added popped out of alignment so I had to push it most of the way home. I didn't have any real tools with me and it started to get dark so I fixed it when I got back. I got some interesting looks along the way...for sure. Someone I know drove by so I throttled enough that it was more obviously pushing as I threw my head back, faking more acceleration then there really was...heh..

It felt like I could go quite a bit faster but I knew the tensioner was fragile when I started out. I loaded it into the truck a little too soon I guess. Along the way it got jostled a bit so it didn't really work when I pulled it out of the truck. Rather than drive back home I tried a few different field fixes and then it seemed to work great (I went 1/2 mile and faster than parade-speed ;) ) until it popped out again. I think I'll have to add a small toolbox..yup,yup...

On the bench my battery seems to give about 600w, give or take, so that's probably about what I had to work with on my little trip. The low voltage alarm goes off a little after 500w but it doesn't seem to be counting the light's wattage at all. With just the light on it switches between showing 0 and 10w output..split the difference and that's about what the inverter should draw idling (the manual says 6w, and the display changes every 3sec..plausible). The plan is to get 2 more 20ah batteries for more capacity/range (not that I know its true range yet) and traction. That'll increase the trailer weight to at around 80lbs...right now it's 55-ish..more batteries should make 1.5kw peaks possible, yeah?..

My only real concern now is w/ the rear of the frame. I'm not sure the tiny steel tubes can handle the power so I'll make a pair of long  bolts to use as supports. I'll add another set of drop outs to the yellow forks (so it'll have 3 sets) so I can bolt it there and the tubes that hold the wheel already have a convenient hole. I would've already welded the support rods on but the easier it is to adjust things and disassemble it, the better.

I'm gonna see if I can't make the full mile tomorrow and I'm gonna pull out the good camera to get some better pics...assuming nice weather. Knock on wood! :)
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REdiculous

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Re: push-trailer update
« Reply #28 on: May 08, 2010, 12:10:11 AM »
I didn't get pics but will do that soon..was pretty busy today but I did get to test it again...

Wide open throttle for about 1/2 mile hit the battery pretty hard. I was probably past the legal speed limit too..oh well...I don't have functional pedals so it's technically an unregistered motorcycle and illegal anyway. One of the benefits of being out in the middle of nowhere I guess.

The chains stayed on the entire time (yes! finally! ;D) but there was little power towards the end of the run...it was barely limping along. This was w/ a 60w bulb on too, so it was as extreme as the last test run..same basic weight and wind too. At the end of the run the motor was noticeably warm but not too hot...I have a cooling fan in place but it wasn't hooked up..tho the inverter's fan was on I think.

I'm gonna see about getting a remote kill switch for the inverter. Then I could cut all power draws while I coast. The controller has an inhibit terminal I could use instead but then the inverter would idle away a bunch of power for no reason. I think it might be wise to get the bike in working order too so I don't get a ticket/talking-to. I just need a chainring and a few nuts is all.

In the shop I tried a 13-ish watt AC->DC brick powering a little bulb instead of the 60w bulb but I couldn't tell if it made any difference. I hope I can cut that down to something more reasonable..I hate throwing that much power away. Maybe a short string of xmas lights would work. Can I run something besides incandescent bulbs?..no need for lights in the day, afterall...but a radio, if it worked, might be nice.

So yeah..now it's basically a short range motorcycle that doesn't go all that fast. But it's fun as all get-out and nicer than a gas engine in some ways. Maybe next month I'll afford another pair of batteries and see a 3mi range..heh. It'll be interesting to see how well it works when I try to take it on a longer trip...the "motor me around" test is just brutal punishment so I know what it can do. The real goal is to have a more gentle push for 5-10min bursts so I don't have to pedal as hard to keep pace. Maybe I'll huff-n-puff to my limit and then use the motor to get me going a little faster and then coast for a ways..rinse, repeat. I dunno but it'll be nice to be able to get to town without having to pedal the whole way and without using gas...otherwise it costs about $4 per round trip, give or take a quarter or so.

Have a good one! :)
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REdiculous

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Re: push-trailer update
« Reply #29 on: May 09, 2010, 05:27:07 PM »
It turns out that the test route was about 2 miles round trip (I love it when /true/ is handy :D) so it did twice as good as I originally thought. I don't think that's too bad for what I've spent on it so far. I don't count "freebies" like the random 2x4, etc..so about $250-300 for the big-ticket items. $35 treadmill motor (now likely $100-ish), $80 inverter, $85 controller and $50 battery. Even adding another $100 for the trailer frame and the wheel doesn't make it too bad...I think the wheel was $45, so $55 seems fair for the frame/etc.

Even calling it $350-400 doesn't seem too outrageous...I can't find a decent hub motor kit for less than that and they don't come w/ a battery at that point so that option wouldn't even have a range without costing more - it would be more compact and potentially more useful, however. Maybe the RC systems are similarly priced but the only way I know to get the gearing done is through a one-man operation w/o a real web store and I couldn't find an RC-based "kit" anywhere. I didn't even really investigate that option much because of the ridiculously high-rpm motors..

Speaking of RC, the trailer's test run reminded me of an RC car in a way...like I got 10-15mins of hard play and that was it. I'm hoping that doubles or triples by adding more batteries and refining things. I think I need to find one of those towable speed displays the cops put out and see what it can really do. I have a feeling I was over 25mph for a bit but that's just as wild a guess as the range was.

Oh! While I was in town today I got a 48t sprocket and crank arm for nadda..so I can fix my bike. They were really cool and even let me dig through stuff in the back. It was the same place I got the wheel from about 6yrs ago but I hadn't been in there since...they're more of a sporting good store so the bikes and bike-stuff are more expensive and it's geared more toward the spandex/lycra riders but they can still order some good stuff. I usually go to a smaller shop that's more focused on performance bikes and skateboards but they were closed today...cool tho, since I probably saved a few bucks. :)

addition; I tested a 40w bulb and it seems as tho that might be the lower limit...w/ hard accel I felt the pulses I get w/o a bulb, to a lesser degree tho. Does anyone know if pure sine inverters act the same way w/ purely inductive loads? I could upgrade to a higher battery voltage at the same time...I saw some 24v pure sine inverters online that didn't look too expensive..maybe?
« Last Edit: May 09, 2010, 06:02:33 PM by REdiculous »
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zap

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Re: push-trailer update
« Reply #30 on: May 09, 2010, 11:33:15 PM »

Even calling it $350-400 doesn't seem too outrageous...I can't find a decent hub motor kit for less than that and they don't come w/ a battery at that point so that option wouldn't even have a range without costing more -

You're kidding... right? ???

http://endless-sphere.com/forums/viewtopic.php?f=31&t=17976 $200 + shipping (no batteries)

http://endless-sphere.com/forums/viewtopic.php?f=31&t=14731 $249 shipped! (no batteries)

$200 would buy a lot of battery... $100 would still buy a decent enough amount.

REdiculous

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Re: push-trailer update
« Reply #31 on: May 10, 2010, 04:24:37 AM »
No, I wasn't kidding...notice the qualifier, "decent"...

One of the reasons those won't work for me is the size. I can't run 26" wheels w/o major modification. Kits w/ 20" wheel options are rarely discounted like that, at least from what I've been able to find. I'm not smart enough to get the right discount kit and have it laced to a 20" wheel...sorry...

Also, those aren't very comparable. A 350w geared hub? C'mon. The 9c is close but not quite there, imo. My controller can deliver 1.5kw and my motor can peak to 2.25kw..1kw continuous should be easy, given the batteries. The controller in the 9c kit is 36v (/48v) 22amps so I wouldn't trust it to push 1kw for long and the motor is listed as 500w....maybe that's de-rated (run@24v) or something tho, I dunno...

If I only count the motor, controller, battery and inverter then it's $250 straight-up, just like the cheap hub kits. Since it requires the trailer frame (really the gear reduction) and a wheel in order to work I added $100 to be more fair.

If I was being even more fair I would've given salvage prices for the trailer frame and wheel since they didn't really cost me anything and used parts would work fine. Instead I listed the wheel's retail value and gave the frame (gear-reduction and chains, really) a $55 value. That seems pretty reasonable to me...and then I added another $50 on top of that to be sure.

Hub kits are more efficient and easier to install (I am a fan!) but I'm a DIYer...I like the challenge and satisfaction of making my own stuff. This time I think it paid off by being somewhat cheaper, even though efficiency suffered a bit. I only spent $250 directly (+ $150 in on-hand value) and it pushes now..it has range now. Besides that the specs are higher as well. YMMV. ;)
« Last Edit: May 10, 2010, 04:30:16 AM by REdiculous »
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REdiculous

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Re: push-trailer update
« Reply #32 on: May 10, 2010, 09:51:55 PM »
I don't know why I didn't think about it sooner but it turns out that I can (almost) use my charger instead of the light to solve the pure-inductive-load problem.

It sounds like an attempt at overunity in a way, but that's not the idea. I have to have a resistive load anyway..this way it's a leaky pipe instead of a down-right waste of 60w. I just leave the charger connected..plug it into the inverter to go and the wall to charge.

I just need to get a larger/better charger than I've been not-using. Mine's 25w..I think 60-100w would be better. I tried my charger and it was obviously better than no resistive load but it wasn't as good as a 40w bulb and 60w seemed perfect.

I just need a new charger I guess...and batteries and a remote switch and..and..later.
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