New Surly Big Dummy build with only used parts

[highlandr]

Hello, I've been lurking this forum for long enough that it's time I register and share my electric dream. It's inspired by ideas and builders on this site from all over the world, especially those that get by with whatever they have available (shout out to Naeem!).

My name is Chris, I'm a shepherd in a remote part of Washington. I raise a small group of mostly goats (I have a handful of llamas, yaks, and sheep as well) doing intensive grazing and weed control, and am looking to make a bicycle that can get me 15 miles into town once or twice a week. I've had a big dummy for years, and while it's a great bike, the distance and hills lead me to use my small truck for simple errands, and I would much rather use the bike.

I like the idea of using all of the existing gears, and driving the left side with a tandem chainring (like the stokemonkey design). Will make the bike more flexible for both pulling heavy loads and covering ground quickly when empty. So I'm going to try to find either a used hub motor or configure a scrap yard electric motor to drive a chainring on the left side. I was fortunate enough to find an 06 Prius that had just wrecked, and was able to pull the battery. Each cell is 7.6v nominal, 8.3v is the cutoff voltage I will use. 7 in series gives me 58.1v full charge.

I like the idea of using a it controller and programming it myself, but I'm still doing research. Just wanted to log my thoughts, introduce myself, and say thank you to the forum members here.

Chris

 

[E-HP]

Hello, I've been lurking this forum for long enough that it's time I register and share my electric dream. It's inspired by ideas and builders on this site from all over the world, especially those that get by with whatever they have available (shout out to Naeem!).

My name is Chris, I'm a shepherd in a remote part of Washington. I raise a small group of mostly goats (I have a handful of llamas, yaks, and sheep as well) doing intensive grazing and weed control, and am looking to make a bicycle that can get me 15 miles into town once or twice a week. I've had a big dummy for years, and while it's a great bike, the distance and hills lead me to use my small truck for simple errands, and I would much rather use the bike.

I like the idea of using all of the existing gears, and driving the left side with a tandem chainring (like the stokemonkey design). Will make the bike more flexible for both pulling heavy loads and covering ground quickly when empty. So I'm going to try to find either a used hub motor or configure a scrap yard electric motor to drive a chainring on the left side. I was fortunate enough to find an 06 Prius that had just wrecked, and was able to pull the battery. Each cell is 7.6v nominal, 8.3v is the cutoff voltage I will use. 7 in series gives me 58.1v full charge.

I like the idea of using a it controller and programming it myself, but I'm still doing research. Just wanted to log my thoughts, introduce myself, and say thank you to the forum members here.

Chris

I love those Surlys and the recycle/re-use part of your plan. Tell us more about those hills.

And, welcome to the forum.

 

[amberwolf]

I like the idea of using all of the existing gears, and driving the left side with a tandem chainring (like the stokemonkey design).

if you're using the existing gears (with the motor), you're driving the *right* side of the wheel, though it would be the *left* side of the BB. is that what you mean?

if so, that's alot like my crazybike2's original middrives worked.

to see what kind of power/torque/etc will be needed for your situation, i recommend goiong to http://ebikes.ca/simulator, reading the entire page so you know how it works and what everything does. then play with various setups, using the 'middrive' checkbox for the chosen motor(s) so you can enter your gearing, and so on. ti'll help you see what might wokr ok, and hwat might overheat, etc.

So I'm going to try to find either a used hub motor or configure a scrap yard electric motor to drive a chainring on the left side.

if you don't mind the inefficiency of brushed motors, there are many cheap used powerchair motors with hefty reduction gearboxes out there that will give intense torque thru the drivetrain (enough to destroy it and the wheel if if derails and you don't stop it immediately :lol: ).

speed and torque will depend on the gearing chosen between the gearbox output (axle mount for the original wheel) and the tandem input, as well as teh voltage of the system and the current limit of the controller.

i've run them as high as 48v, for 24v designs, but even 36v will give you more torque than you probably need, enoguh to flex the bike frame. :lol:

they are often designed to clamp direclty ot the powerchair / wheelchair frame tubes, so they can be easy to mount to a long enough bike frame, like yours. you can also use sliding mounting plates like i did, so the chain is easy to tension.


if you have the money, ebikes.ca has stokemonkey kits on clearance, still not cheap but a fair discount from original.

I like the idea of using a it controller and programming it myself, but I'm still doing research.

not sure what an "it controller" is, but designing/programming / building your own contorller, especially one fro brushless motors for higher currents, isn't really trivial, and you'll probably spend a fair bit of money on destroyed parts in prototyping. there's a number of good threads for diy controllers and powerstages around here, if you do choose that route, that will help you a lot.

a brushed diy is a lot easier, but the powerstage design is still sensitive to layout/wiring/parts choice/etc; i ended up using commercially available stuff from 4qd and curtis for original crazybike2 middrives after i destroyed too many prototypes to list. don't have threads for the prototype stuff, most of it was long before i found es; some of it might be on my electricle.blogspot.com blog, most probably isn't.


there are build-it-yourself already-=designed contrllers like lebowski and vesc, etc., for brushless bldc motors, here on the forum, if you want to go that route. more expensive than prebuilt for the same features, but more programmable / etc for that cost.

really cheap generic prebuilt stuff that generally works but isn't customizable is an easy way to go for starting out, and if it's not good enough then go the other routes.

 

[markz]

I prefer to see pictures!

 

[highlandr]

I love those Surlys and the recycle/re-use part of your plan. Tell us more about those hills.

And, welcome to the forum.

I'm in NE Washington in the mountains, and while there are some flat sections of road, most is short (1/2 mile) ups and downs. During the summer when I'm higher up with the animals, I'll have long downhill grades to town and long climbs coming home (4 or 5 mile climbs).

I prefer to see pictures!

Here's us in the mountains, and the prius battery to start...
View attachment 1

 

[highlandr]

if you're using the existing gears (with the motor), you're driving the *right* side of the wheel, though it would be the *left* side of the BB. is that what you mean?

Yes, your crazybike2 is very inspiring, I'm trying to read as much as I can about it.

To see what kind of power/torque/etc will be needed for your situation, i recommend goiong to http://ebikes.ca/simulator, reading the entire page so you know how it works and what everything does. then play with various setups, using the 'middrive' checkbox for the chosen motor(s) so you can enter your gearing, and so on. ti'll help you see what might wokr ok, and hwat might overheat, etc.

I'll start working my way through simulations next time I'm at the library.

If you don't mind the inefficiency of brushed motors, there are many cheap used powerchair motors with hefty reduction gearboxes out there that will give intense torque thru the drivetrain (enough to destroy it and the wheel if if derails and you don't stop it immediately :lol: ).

Efficiency is important to me, and I think I'll be able to find an older used hub cheap enough for me to afford. I'm trying to spend the least amount I can, but want something that works well so that I can really use it.

if you have the money, ebikes.ca has stokemonkey kits on clearance, still not cheap but a fair discount from original.

I've considered just buying the motor from him, for $120 it would get me something that works well and I could make my own mounting setup. But I'm trying to keep the budget as tight as I can, we will see.

not sure what an "it controller" is, but designing/programming / building your own contorller, especially one fro brushless motors for higher currents, isn't really trivial, and you'll probably spend a fair bit of money on destroyed parts in prototyping. there's a number of good threads for diy controllers and powerstages around here, if you do choose that route, that will help you a lot.

a brushed diy is a lot easier, but the powerstage design is still sensitive to layout/wiring/parts choice/etc; i ended up using commercially available stuff from 4qd and curtis for original crazybike2 middrives after i destroyed too many prototypes to list. don't have threads for the prototype stuff, most of it was long before i found es; some of it might be on my electricle.blogspot.com blog, most probably isn't.


there are build-it-yourself already-=designed contrllers like lebowski and vesc, etc., for brushless bldc motors, here on the forum, if you want to go that route. more expensive than prebuilt for the same features, but more programmable / etc for that cost.

really cheap generic prebuilt stuff that generally works but isn't customizable is an easy way to go for starting out, and if it's not good enough then go the other routes.

I meant to say KT controller, as that seemed like an affordable option at something already made that could be programmed. The vesc looks like an even better option if I can find a pcb, I'm no stranger to soldering. Thank you for that!

 

[amberwolf]

Yes, your crazybike2 is very inspiring, I'm trying to read as much as I can about it.

then definitely go to the http://electricle.blogspot.com as theres' more detailed info on early versions of it there, that may be useful, than there is in the thread here on es. and if you have questions you cna just post them in that thread or in this one.

Efficiency is important to me, and I think I'll be able to find an older used hub cheap enough for me to afford. I'm trying to spend the least amount I can, but want something that works well so that I can really use it.

if you're using the bikes' gearing, a small dd hub will potentially be more efficient beause it has no gearing to waste power (every reduction stage uses up some percertange of power). but depending on laoding, a geared hub might be more efficient in some sitautions; the simulator wil help you see how this works.

a smalle motor will be lighter, since you probably don't need ahuge amount of power over a long time, so you probaloy don't need big dd motors like the 1000w+ stuff, small 500w and less motors will likely work fine.

i recommend you look up the various hubmotor middrive builds for mounting ideas. apl has a few, as well as a diy motor thread where he's already built one from scratch and is working on a second design. in the non-hubmotor bike section there is a sticky index with links to others. crossbreak ahs at least one, maybe towo.

some work like stokemonky, some don't.