RC Electric Brushcutter

[Hardcarve1]

I was never happy with the off the shelf units that look under powered, light weight and cheap. So I had just enough stuff sitting in the shed to make a RC unit but just needed to find the right ICE brush cutter. I was always looking for a straight shaft good quality unit that had a stuffed motor that was ready for the rubbish. Luck came after a few months looking when I came across a very old Echo 50cc unit that was sitting in the shed for the last 10 years.
When pulled apart the running gear was in top condition with all bearings & gears in great condition but I decided to replace all the bearings and clean the thing up. Because it's old everything is built to last and when I had the local mower man look at it he said nothing on the market looks like that any more.

It has a Turnigy 80-100-130 with CC HV100 speed controller, BEC is a Turnigy HV and the throttle interface is the via a modified Turnigy servo tester.

moderator edit to cross-post:
"Wack-Off 5065™ E-trimmer"
http://endless-sphere.com/forums/viewtopic.php?f=1&t=42411



Machined up an adapter for the engine shaft using the old spline from the ICE clutch.

View attachment 3
I replaced all the motor screws with stainless cap screws as the originals were starting to strip the phillips heads.


I had no guard come with the brushcutter so I found an old one and made up a new mounting bracket. Others would put holes to lighten things up but I like the soloid look with no bling.




I have still to tidy up how the battery case will fit on but it's been doing some work around the yard already and the thing is so much better than a ICE machine. I had a very old pack of A123 2S6P and the power was much better than any 50cc unit that I have used. I also need to put a mesh cage around the engine to stop the fan from eating things up. What I realy want to do is charge it from a solar panel and have a true green brushcutter.
next on the list is a self propeled Honda lawn mower that my brother has sitting around.

 

[neptronix]

That's cool as hell, man. I like seeing people green up every possible thing that has an ICE.

Kinda tired of hearing 2 stroke leaf blowers outside my apartment complex at this time. Don't they know that some zippy lipos and a turnigy motor would be way better?!

 

[johnrobholmes]

wow, thats slick!

 

[liveforphysics]

Nice! Love it!

 

[wineboyrider]

Sweet!

 

[katou]

That is some SERIOUS tight, clean work, very impressed! I especially like the stainless bars around the motor. I know how tough it can be to bend two the same, and they look perfect.

Katou

 

[spinningmagnets]

You definitely have skills! Perhaps make a minor adjustment to the motor base to make the power-head a detachable module?

Since electrical components that are well-suited to the tasks they are assigned seem to last a very long time, such a motor/battery/controller module could be made to attach to a variety of modified tools, which might prove to be quite useful.

I recall gutting a 12V cordless drill battery that wouldn't hold its charge any more (after 5 years of abuse). Then I took a power cord and two alligator clips from a fried car battery charger, and attached them inside the cordless-drill battery case.

The 12V drill wasn't hugely powerful, but I took some nearly free trash and ended up with a drill I could hook up to my car.

 

[Hardcarve1]

Thanks for the comments guys.
I put some better batteries on and went on a mission to cut through anything that grew out of the ground. I was using 3mm line and the thing is crazy, it just cuts through any type of grass and holds the revs very well. All the noise is in the line going thru the air but the great thing is their is no vibration and heat coming out the back of it. It's very smooth and I think you could cut all day but I had to put it away as the wife was getting some idea's of me doing other garden work since I looked so happy cutting the grass.

Katou,
I know what you mean about the tube bending and to be honest it was after a few efforts before I managed to get a close match. I made up a simple bending jig out of some scrap plastic sheet and after bending I placed it into a vice to slightly crush the tube back to round. I used 9.7mm 304 S/S tube with a 1.2mm wall thickness so the frame is very strong and then I tig welded the frame up.
View attachment 3



Spinningmagnets,
The power head does come off with two bolts and I guess you could addapt it to other garden devices.
View attachment 017.JPG

Cheers

 

[x88x]

Nice work! I like it. TBH I don't really care much about the whole environmental side, so it is always nice to see purely functional conversions that play on the strengths of electric motors (silent, no vibration, more usable torque, etc). Plus, it holds up as an 'environmental statement' if you care about such things.

 

[dingoEsride]

Very nice job, those machines will make some noise anyway but at least won't have a screaming two stroke motor noise, I recently bought an electric chainsaw cause my petrol one is always hard to start and makes an almighty noise, the electric is quiet and works a treat

 

[Harold in CR]

Nice conversion. You beat me to the finish.

Got any idea what the amp draw and RPM's will be ?? I don't have as big a motor, so, I'm trying to calculate the output you have compared to what I have to work with.

 

[Kingfish]

HC,
That is pretty tricked out man! When I had a farm my best tools for brush were the weed-whacker and chain saw. In Washington State brush = Blackberry brambles = No fun. I had a light-duty electric saw for the jobs close to the house, but with many acres it’s a pain to run heavy-gauge extension cord from one end to the other (though I did it several times before snagging a generator that ran off the PTO). Yours would be perfect for me with a little LiPo backpack.
Touché & good job! KF

 

[johnnythefox]

I don"t know how I missed this.
This is just so right,soon they will be at Lowes or Home Depot.
Great job.

Johnnythefox

 

[Hillhater]

This is just so right,soon they will be at Lowes or Home Depot.

...they already are..Makita etc already produce them.
Only problem is the $1000 + ticket

Features:

* Powered by 36V/2.6Ah Li-Ion battery (BL3626)
* BLDC Motor (Brushless DC Motor). Maintenance free due to no brush.
* LED Warning lamp for battery/motor protection system.
* Indication lamp for battery.
* When battery power has been completely used up; the battery protection circuit will automatically shut off the power supply to the motor.
* Trigger switch. With variable speed control and lock-off button.
* Grass clipping removal function.
* Equipped with reverse switch for easy removal of grass clippings.
* 300mm Nylon cutting head.
* Battery guard.
* Electric Brake.
* Universal Guard.

 

[dogman dan]

I bought two B&D 24v string trimmers last summer. One for the house, one for the lawns I maintain at work. Not quite as powerfull as a gas one, but too much power just eats string with those anyway.

They came with 24v nicads, similar to the ones I already have a bunch of for some drills. So I have 4 batteries avaliable. You can just about get through a normal suburban yard with one pack. But it's also really really easy to rig a 7s nicad pack to run them on. They can come in 18v versions too, so they run fine on 18v making a 5s pack work dandy too. I think when the nicads wear out I'll get some 6s batteries for em.

 

[Hillhater]

Are the B&D units brushless ?
The new Makita ones are , and 36v Li ion batts ..so should perform even better.
but, boy what a big $$ item !

 

[dogman dan]

Pretty sure the B&D one is just a simple brushed motor, like the drills. Works fine for light duty use like edging where the mower can't fit. It's not a brush hog, or a thing that can have a tree pruner chain saw attached. Just a nice light edger. It's been great at work, with a space as big as the condo complex cutting the weight of the string trimmer by about 10 pounds has been a joy. Lots of trim a tiny bit, walk a lot, trim a tiny bit walk a lot. Less noise is greatly appreciated by the residents.

 

[auraslip]

How much do you want for it - not joking.

 

[Hardcarve1]

Just an update on this project as I have been using it with great success but always had the 8s3p A123 pack cable tied to the back. I hated how it always needed to have the plugs connected to run the thing and the watts monitor was just hanging by wires. I built the bateries and electrics in a housing so when I want to start it I just push the momentary pre charge resistor and turn the main on/off switch. I use a cluster of andersen connectors for the balance and charge leads as this is what I use on my bike and it's sort of my standard I want to use on all my battery powered items. leads out the back are a bit messy but work fine.
I will try and upload a sort video of it running.
To do my yard which is a small block 400m2 and do all the fence line and concrete kerbing uses about 2.8Ah, so just over 50% of the pack. Running 26 volts is all thats needed as when it was running up around 40v the thing was noisy and would tear the crap out of the lawn if you got down too much.