Author Topic: 4kw Motor Conversion  (Read 5081 times)

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Offline Wolvenar

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Re: 4kw Motor Conversion
« Reply #15 on: July 20, 2012, 12:46:54 AM »
If you havent poured yet.. I wonder if something to vibrate or shake it a bit while pouring may help with trapped air ( mine had a couple spots)
That is if you confident in the mold holding well..
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Offline Bryan1

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Re: 4kw Motor Conversion
« Reply #16 on: July 20, 2012, 04:34:33 AM »
G'day Wolv,

                  With the 4 holes in the top end plate and I'll pour in very slowly hopefully no air bubbles will occur. Now I went searching for that company I got the epoxy off before only to find the site is now a car park and I went to a servo to look in the yellow pages for other suppliers. The mob I rang are the biggest plastics mob in the state and I was told i would be lucky to find ANY 2 part epoxy in the state as it all had to come from vic as a special order.

                 Anyway as this last pour will be continuous and one solid mass I'm just going to use fiberglass. I do know and have been told that fiberglass won't stick to epoxy but as I said above I can't see any problems using it. If anyone has major concerns just say so.

Cheers Bryan

Offline Wolvenar

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Re: 4kw Motor Conversion
« Reply #17 on: July 20, 2012, 11:41:38 AM »
Seen quite a few documented cases of fiberglass resin failing over the years reading the other sites..
I guess I wouldn't try it myself.
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Offline Bryan1

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Re: 4kw Motor Conversion
« Reply #18 on: July 20, 2012, 04:56:13 PM »
Wolv,
        Last year I made a heating coil for my etching tank out of epoxy and found the epoxy went soft on me around 80C. Now with those 84 off N50 neos and the chance of the genny going into a runaway I am worried about overheating. Today I will ring around and see if I can source some high temp epoxy and that stator I made for the mini is going thru a heat test. I'll cut a bit off and put it in the oven at 130C and see if if it breaks down. My mate who is a blacksmith is in the same boat trying to get some coke for his forge, no-one in the state stocks coke anymore and it will cost a bomb to get a truck load over from interstate.

     Also today I'll be finding out when those traction batteries will be turning up so now this 4kw motor conversion has become an urgent job as I'm sure everything this 4kw can throw out that 24 volt 700AH bank will soak it up and still want more. I have some 1 metre lengths of pine so a 2 metre blade set will be made in the next few days and i'll throw a F&P genny up for the duration until the 4kw is  finished.

Cheers Bryan

Offline rossw

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Re: 4kw Motor Conversion
« Reply #19 on: July 20, 2012, 05:40:39 PM »
I'm sure everything this 4kw can throw out that 24 volt 700AH bank will soak it up and still want more.

I wouldn't like to hit a 700AH bank with more than about 70 to 100A.

At 24V, you're looking at 40A per kW, so 160 amps odd at 4kW and who knows how much at peaks.
It'll certainly drive the volts up on your batteries, I'd be thinking pretty hard about how you're going to tame it.

Offline tomw

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Re: 4kw Motor Conversion
« Reply #20 on: July 20, 2012, 08:48:23 PM »
My mate who is a blacksmith is in the same boat trying to get some coke for his forge, no-one in the state stocks coke anymore and it will cost a bomb to get a truck load over from interstate.


Cheers Bryan

Bryan;

Isn't coke just coal made into charcoal? IE: heat it in an air starved environment until the volatiles boil Away. Result is basically pure carbon. I used to make charcoal for melting aluminum and seem to recall that coke is coal based charcoal from my researching charcoal making?

For all I know coal is even harder to find there?

Just thinking out loud.


Tom
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Offline rossw

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Re: 4kw Motor Conversion
« Reply #21 on: July 20, 2012, 09:37:05 PM »
Isn't coke just coal made into charcoal? IE: heat it in an air starved environment until the volatiles boil Away. Result is basically pure carbon. I used to make charcoal for melting aluminum and seem to recall that coke is coal based charcoal from my researching charcoal making?

Charcoal is very soft, fragile, delicate stuff.
Coke seems to be much harder, more resiliant stuff.
I too thought it was coal "cooked" in an oxygen-poor oven similar to charcoal, but there's something to make it tougher, harder. I also recall that coke seems to be "pockmarked" - whereas charcoal seems not to be.

Hmm, some research http://en.wikipedia.org/wiki/Coke_%28fuel%29 says:
"Coke is the solid carbonaceous material derived from destructive distillation of low-ash, low-sulfur bituminous coal. Cokes from coal are grey, hard, and porous."

Offline Bryan1

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Re: 4kw Motor Conversion
« Reply #22 on: July 27, 2012, 07:41:54 PM »
G'day Guy's,
                    Well after trying to find 2 part high temp epoxy over is like trying to find a virgin in a whorehouse..... so due to impatience and lack of $$$$ I went ahead and did the final pour using fiberglass. I cut up some glass mate and mixed it in the resin and man it was fun getting in the holes but time persisted and in the end it took about a litre of resin. This morning I couldn't wait to get the mold off and see if I made a huge stuffup but it turned out pretty good I reckon. There isn't any air pockets around the magnets and only one air pocket at the top which I'll machine off. I measured the OD and it's 0.2mm bigger so a light lick in the big lathe will set the gap and true it up.

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              Anyway now i got those 1000AH traction batteries this project has become pretty urgent so for now I'm just going to use the PTO on my Fiat tractor for power and I'll look for an old lister for the drive long term. For me to build a tower, buy and run heavy cable over 100 metres it will take 6 numbers in lotto just to afford it so hopefully I can find an old lister and run it on vege and sump oil.

Cheers Bryan

Offline Bryan1

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Re: 4kw Motor Conversion
« Reply #23 on: July 28, 2012, 07:45:59 PM »
G'day Guy's,
                     Well got the one wire all installed and wired up for the first test which will be one delta. Pouring down rain here so next jobbie is getting rid of all the metal swarf off the big lathe so I can machine the magnet rotor and get that 1mm clearance.

For winding the coils I just had to use that patented Oztules nail method and I gotta say it worked a treat.

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Here a pic of my first attempt at wiring a motor for the one wire test and I will taking the motor to a rewind shop for the final wind as somethings are best done by the experts.

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Hopefully the sun will be out later to give my shed bank a bit of a charge and when I do the test I'll have a go at making my first movie and stick it up on youtube.

Cheers Bryan

Offline Wolvenar

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Re: 4kw Motor Conversion
« Reply #24 on: July 29, 2012, 02:59:36 AM »
Bryan, after a short time of practice rewinding these motors is rather less trouble than you might think.

I've done countless rewinds.. like this trolling motor refit..
I changed the voltage, and went from copper clad to full copper.
This added a LOT of available power, so I changed out the prop to make use of it.
Yeah it might be non standard in how its wound, but it was something zubbs said should work for this particular application to make the winding all fit easier. It was a tad thicker wire, and  few more turns each. This was first dipped in epoxy a  couple times to replace the need for cardboard insulators etc, then again after it was wound.
Yup another one of my Zubbly guided adventures, and it worked (works) fantastic.

Sorry I guess I didn't get the best of pictures back then.
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Offline Bryan1

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Re: 4kw Motor Conversion
« Reply #25 on: July 29, 2012, 08:13:08 PM »
G'day Guy's,
                    This morning dod a big cleanup on the lathe and machined down the mag rotor, man it was fun as the first cut went to dig in but luckily caught it in time. In the end I wound up the dial to 100hz and put on a quick feed rate and held onto the tailstock with both arms. I finished it off with some emery cloth and got the size down to 113.5mm which is a 1.5mm gap(0.60").

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                  The next jobbie is making up a fixture to hold the motor secure so I can easily put the rotor in & out then it's ready for the single wire test.( changed one to single as not to confuse Ross).

Cheers Bryan

Offline bj

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Re: 4kw Motor Conversion
« Reply #26 on: July 29, 2012, 09:15:51 PM »
Turned down nice Bryan.  As long as you keep the rev's below 10,000, should hold fine. ;D
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Offline Bryan1

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Re: 4kw Motor Conversion
« Reply #27 on: August 03, 2012, 10:46:01 PM »
G'day Guys,
                    Well got into it this morning and installed the mag rotor into the motor and did the single wire test.

Here's a pic of the setup, I used the lifting jib on my Fiat tractor and my 1 ton chain block to lower it in. The barrel is a 'G' sized Warman pump Bearing housing and weighs about 400Kg's +. As it turned out the hole in the end cover is about 2mm bigger than the locating flange on the motor and I sat the motor on some RHS and just had the bolts finger tight.

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Heres a pic of the rotor in place.

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Now the tapped hole in the end of the shaft is M16 and I only had a M12 eyebolt so a quick jobbie in the lathe to drill and tap a M12 hole in a M16 bolts did the trick.

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Now onto the single wire test.....

I did the test at 200rpm and the rotor has no signs of cogging at all.

One Delta

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Two Delta

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One Star

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Two Star

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I reckon going One Delta will be the go so with 0.9232 volts @ 200rpm works out to
0.9232 / 1.73 = 0.533641618/ 200 =0.002668208 volt per rev.
Now for a 200rpm cutin 25 volts /(000266208 x 200) = 46.847921901
So 47 turns should give 25 volts @ 200rpm.

Now I can take the motor to the rewind shop and depending on the slot fill i may be able to use thicker wire than the 14awg I have here.

Cheers Bryan