# Soldering Motor Internals



## major (Apr 4, 2008)

jeff mccabe said:


> Hi,
> My name is Jeff. Im building up 2 11" GE motors for my FFR Cobra project and I need to solder some Com leads. I think I need silver solder, but dont know the recommended % silver ?
> Any guidance would be helpful.


Hi Jeff,

Use SilFos brazing alloy. http://www.silfos.com/htmdocs/product_support/alloy_selection_guide.html Choose the product closest to your needs. 

Major


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## jeff mccabe (Feb 23, 2010)

Major,
Thank you, I was about to send you a private email
I knew you would know !

Jeff




major said:


> Hi Jeff,
> 
> Use SilFos brazing alloy. http://www.silfos.com/htmdocs/product_support/alloy_selection_guide.html Choose the product closest to your needs.
> 
> Major


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## jeff mccabe (Feb 23, 2010)

Major,
I bought 6% sil-fos but cant seem to get enough heat with my map gas to get it to flow ?
Any help would be appreciated !

Jeff McCabe
408-265-4745




major said:


> Hi Jeff,
> 
> Use SilFos brazing alloy. http://www.silfos.com/htmdocs/product_support/alloy_selection_guide.html Choose the product closest to your needs.
> 
> Major


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## major (Apr 4, 2008)

jeff mccabe said:


> Major,
> I bought 6% sil-fos but cant seem to get enough heat with my map gas to get it to flow ?
> Any help would be appreciated !


Hi Jeff,

I've always seen it done with oxy Acetylene or electric resistance heating. Most of that has been skilled tradesmen or factory workers doing the deed. I have done it a few times myself with the torch. And that was years ago. I do remember the torch giving a localized heat where it didn't overheat the coil insulation just a few inches away. Sorta get in hot and get out fast type of thing.

Too bad the old motor dog Jim H ain't around. He was handy at it.

major


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## jeff mccabe (Feb 23, 2010)

Major,
Yes , Jim was very helpful..hope he is well !
How about an silver-tin solder it has a much lower meting tempurature of 435f and a flow of 550F compared to 1200+ F from the 6% stuff. 
I know my insulation is only good for just over 300F and over 220F it starts to bubble( dont ask me how I know this 
I think ,ill run and pick some up before the close for the weekend.

Thanks for your help, Jeff




major said:


> Hi Jeff,
> 
> I've always seen it done with oxy Acetylene or electric resistance heating. Most of that has been skilled tradesmen or factory workers doing the deed. I have done it a few times myself with the torch. And that was years ago. I do remember the torch giving a localized heat where it didn't overheat the coil insulation just a few inches away. Sorta get in hot and get out fast type of thing.
> 
> ...


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## DIYguy (Sep 18, 2008)

I think the best for motor applications is Sil Fos 15. As Major says, Oxy-acetylene is definitely better because it is hotter... but also because the torches with the little MAP gas kits are usually too small. MAP can be fine if u have a larger torch. I just drilled out my little torch and used MAP gas... it works ok..

Another tip is to not use a big clamp to hold the parts together. Get a small pair of vise grips, take a screw and grind it to a dull point, weld it on the jaws so there isn't too much contact area. This way u don't wick too much heat away.


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## major (Apr 4, 2008)

jeff mccabe said:


> How about an silver-tin solder it has a much lower meting tempurature of 435f and a flow of 550F compared to 1200+ F from the 6% stuff.


I wouldn't rely on it for any mechanical or structural support.


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## jeff mccabe (Feb 23, 2010)

Major,
This is the piece im soldering. No stress on the connection, just a connection for the far brush holder.
It still needs to be cleaned up and sealed with insulating paint by the cable, but what do you think ?

Thanks, Jeff





major said:


> I wouldn't rely on it for any mechanical or structural support.


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## jeff mccabe (Feb 23, 2010)

My nozzle is the same one I use for my propane torch. It has about 1/2" i.d opening, so thats not it. It just doesnt heat it up fast enough. I have an oxy- acetylene at work , so I will try the sil-fos again monday.

Thanks, Jeff 




DIYguy said:


> I think the best for motor applications is Sil Fos 15. As Major says, Oxy-acetylene is definitely better because it is hotter... but also because the torches with the little MAP gas kits are usually too small. MAP can be fine if u have a larger torch. I just drilled out my little torch and used MAP gas... it works ok..
> 
> Another tip is to not use a big clamp to hold the parts together. Get a small pair of vise grips, take a screw and grind it to a dull point, weld it on the jaws so there isn't too much contact area. This way u don't wick too much heat away.


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## major (Apr 4, 2008)

jeff mccabe said:


> Major,
> This is the piece im soldering. No stress on the connection, just a connection for the far brush holder.
> It still needs to be cleaned up and sealed with insulating paint by the cable, but what do you think ?


I don't think the brazing alloy will wick-up like solder. For that you may be better off using actual silver solder with solder flux (non acid) with the lower temperature torch. Sorry, I thought you were fixing together those copper plates and brass terminals. Yes, I'd use a good high temp solder (around 400-500F), not braze for what I'd call a flag terminal. In fact I've done flag terminals like this using solder and rosin flux. It is a lot like sweating copper plumbing. The solder will wick into the joint.


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## jeff mccabe (Feb 23, 2010)

Major,
Thanks again for your help. Well now I have some good Sil-fos for when I do need it. 

Jeff




major said:


> I don't think the brazing alloy will wick-up like solder. For that you may be better off using actual silver solder with solder flux (non acid) with the lower temperature torch. Sorry, I thought you were fixing together those copper plates and brass terminals. Yes, I'd use a good high temp solder (around 400-500F), not braze for what I'd call a flag terminal. In fact I've done flag terminals like this using solder and rosin flux. It is a lot like sweating copper plumbing. The solder will wick into the joint.


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## DIYguy (Sep 18, 2008)

Ya, sorry, I thought you were doing solid copper to copper or copper to brass connections. 
Just to clear up for anyone reading..... based on your comment of torch (1/2") . . I realized you were probably using MAP gas by itself with a solder torch. Solder torches actually have a much smaller orifice opening, but the torch mixes room air with the stream via venturi effect, that's why it looks larger.
For Sil Fos (which is actually brazing, not soldering due to higher temps) you need to mix MAP with Oxygen, like you would with Acetylene and use a similar torch. . . perhaps one size up.
Here are a few pics....
Adjust torch to a neutral flame, one with a small bright blue feather close to the tip... perhaps 1/4 to 3/8" in length. . .(this depends on size of tip, longer for bigger tip size)


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## jeff mccabe (Feb 23, 2010)

You are definitely playing with more flame than I was! What does the blending valve look like. Would like to upgrade my setup.

Jeff






DIYguy said:


> Ya, sorry, I thought you were doing solid copper to copper or copper to brass connections.
> Just to clear up for anyone reading..... based on your comment of torch (1/2") . . I realized you were probably using MAP gas by itself with a solder torch. Solder torches actually have a much smaller orifice opening, but the torch mixes room air with the stream via venturi effect, that's why it looks larger.
> For Sil Fos (which is actually brazing, not soldering due to higher temps) you need to mix MAP with Oxygen, like you would with Acetylene and use a similar torch. . . perhaps one size up.
> Here are a few pics....
> Adjust torch to a neutral flame, one with a small bright blue feather close to the tip... perhaps 1/4 to 3/8" in length. . .(this depends on size of tip, longer for bigger tip size)


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## DIYguy (Sep 18, 2008)

It's actually an el-cheapo kit costs about $40 or so. But it will dish out some decent heat for short periods. I used 3 oxygen bottles and still on the first MAP bottle to braze all connections on this 13" coil set. Two of the four coils are double ribbon (4 strips) of copper. Again, I drilled out the tip to get a little more umph. There are separate mini-regulators. Pic attached.


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## jeff mccabe (Feb 23, 2010)

Nice coil wrap their!
This is next for me also. I still need to get the cotton rolls . I have plenty of varnish to seal them afterwards.
Jeff





DIYguy said:


> It's actually an el-cheapo kit costs about $40 or so. But it will dish out some decent heat for short periods. I used 3 oxygen bottles and still on the first MAP bottle to braze all connections on this 13" coil set. Two of the four coils are double ribbon (4 strips) of copper. Again, I drilled out the tip to get a little more umph. There are separate mini-regulators. Pic attached.


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## DIYguy (Sep 18, 2008)

jeff mccabe said:


> Nice coil wrap their!
> This is next for me also. I still need to get the cotton rolls . I have plenty of varnish to seal them afterwards.
> Jeff


Jeff,
Hold on there cowboy. Lol first off, u need to get glass tape to wrap the coils. 3M makes one. Overlap by half each time around. I'll check the number 4 u. Secondly, u will need to take them to a motor shop for a dip and bake in their oven. Preferably twice. I did look into DIY on this, but I don't think it makes any sense.


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## DIYguy (Sep 18, 2008)

U need to maintain the Class "H" temperature rating I would assume. So get Scotch 3M #69 tape. I use the 3/4" wide stuff. Too wide is not good either. The same goes for the resin, it needs to be rated for class H (180 C).Perhaps u know all this... but it's better to state it just in case. 

I'm sure Major has more to add. Thanks to him, I was able to make one motor out of two sets of field coils. I had two 13" motors that were compound wound. I used the two heavy coils out of each to make one series wound motor. Major helped me to understand the best ratio between the field coils and armature winding. I had to remove some copper from one set of coils to get it right. I also added several laminations to each end of the pole shoes to lengthen them as much as possible as they were shorter than the armature area. It's a nice motor with both end bells aluminum. 321 lbs is good for a 13. 
I like the look of those GE 11's. I have one just like them if u need a spare. I'm a big fan of GE motors. They are possibly the best. Many of the racers use them.


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## jeff mccabe (Feb 23, 2010)

Jim Husted prefers cotton cloth to wrap the coils. He said glass works also, but just not what he prefers. 
Here's a question for you or Major...The GE11 already has H class insulation and the field coils arent wrapped, so why wrap them now. Is it because were running them at a lot higher voltage ?
I will only be running one 11" in my Cobra, the second one is my backup in case I melt the first one 

Jeff





DIYguy said:


> Jeff,
> Hold on there cowboy. Lol first off, u need to get glass tape to wrap the coils. 3M makes one. Overlap by half each time around. I'll check the number 4 u. Secondly, u will need to take them to a motor shop for a dip and bake in their oven. Preferably twice. I did look into DIY on this, but I don't think it makes any sense.


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## major (Apr 4, 2008)

jeff mccabe said:


> Jim Husted prefers cotton cloth to wrap the coils. He said glass works also, but just not what he prefers.
> Here's a question for you or Major...The GE11 already has H class insulation and the field coils arent wrapped, so why wrap them now. Is it because were running them at a lot higher voltage ?


Hi Jeff,

I'm old school on this stuff and like to see field coils wrapped. Half lap layer. If you get cotton completely saturated with the resin (lots call it varnish but it is really a polyester resin) then I guess it's o.k., but I think glass would be better cause it won't support combustion, but it won't form as tightly as cotton. Over the past few decades lots of motor manufacturers have eliminated the tape. Just cost reduction. I guess it works. The wire coating is really tough stuff and likely good to 600, maybe 1000 volts. I think it better to have the coils wrapped and impregnated. It adds a good layer between wire and the steel poles and frame and sticks everything together to prevent vibration induced abrasion.

major


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## DIYguy (Sep 18, 2008)

Glad Major answered that. . . because I wouldn't have had a very informed reply.


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## DIYguy (Sep 18, 2008)

Jeff,
If I could hijack this thread for a moment. . . I have to tell you that I love the Cobra and you are building my dream car.  Please tell me this is the new MK4 from Factory Five. If so, I wanna hear more . . what stage are you at???? Where is your build thread!!??? .
Please pm me with details. 

Cheers,
Gary


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## jeff mccabe (Feb 23, 2010)

Gary,
Heres a link or two to my project. It is an older FFR mk2 that was never finished by the previous owner.
http://www.ffcars.com/forums/17-factory-five-roadsters/246129-let-my-electric-roadster-begin.html

http://evalbum.com/3561

The project is moving along, not as fast as I would like though. I have been calaberating the last few months with a few people on the east coast on designing the battery pack.



Jeff





DIYguy said:


> Jeff,
> If I could hijack this thread for a moment. . . I have to tell you that I love the Cobra and you are building my dream car.  Please tell me this is the new MK4 from Factory Five. If so, I wanna hear more . . what stage are you at???? Where is your build thread!!??? .
> Please pm me with details.
> 
> ...


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