10SI Project

[squarebob]

I am working on a project for the RC flying club I belong to. We have moved to a new flying field that has no grid power so I am building a a power source. It will consist of an engine driven alternator, and a solar panel to charge 2 6v golf cart batteries in series. It will have 12v and 120 volt outlets. Folks can plug their 12v battery chargers into banana jacks or use 120VAC power from a 1500w inverter. The first phase is the engine driven alternator. I picked up a 99cc, 4 stroke OHV engine from Harbor Freight for $79.00. They claim about 3HP. I then got a 10SI from the auto parts store, $29.00 + $15.00 core charge. I first made some adapter plates to be able to mount the alt in a direct drive setup.

[squarebob]

Next I got the coupler pieces and modified the one to fit on the 10SI. I bored the coupler so I could install the nut and secure the coupler to the alt shaft.

[squarebob]

Now to bolt it all together!! So far things have gone pretty smooth.

[BioHazard]

Nice work! Curious to see how many amps you get...

[squarebob]

Here is the curve for the 10SI. Looks like I should get about 48 Amps at 3600 RPM and 23 Amps at 1600 RPM. 48 x 14.5V = 580 watts. At 50% efficiency thats 1160w input needed. 2HP per KW = 2.32 HP. So if my math is correct, the little engine should spin the alt with no problems. Hopefully I can get it finished this week and do some testing.

Bob

[veggie]

squarebob,

That's a great little project !
Simple and clean. Should prove to be very reliable.
Rebuild kits for the 10Si are very inexpensive.
Bearings, brushes, and diodes for $20 !

If you every want to step up, I think the 12Si should bolt right in place.
Gives 94 amps and has heavier windings.

nice job,
veggie

[Ronmar]

You should be able to do 48A on 3HP just fine...  Cool build.  What do you fly?

[Ronmar]

I then got a 10SI from the auto parts store, $29.00 + $15.00 core charge.

Bob, can you elaborate on this?  Where did you get the 10SI for $29 + $15 core?

Thanks

Ron

[squarebob]

Ronmar, I fly mostly AMA and SPA precision aerobatic pattern planes. This one pictured is powered by a .91 Cu. In. 4 stroke running 30% nitro fuel.
Bob

[squarebob]

Autozone or Advance Auto has the 10SI for $29.99

part # 7127

I ask for 78 Camaro 350 with air to get them to find it.


http://www.autozone.com/autozone/parts/Alternator/_/N-93xme?filterByKeyWord=7127&fromString=search&isSearchByPartNumber=true

Here is some good info on the 10 and 12 SI

http://www.madelectrical.com/electricaltech/delcoremy.shtml

[rcavictim]

Ronmar, I fly mostly AMA and SPA precision aerobatic pattern planes. This one pictured is powered by a .91 Cu. In. 4 stroke running 30% nitro fuel.
Bob

From that picture and what we know, it appears that you are outstanding in your field!   

[BruceM]

Great project, SquareBob.  Nice plane, too.  Thanks for the link to madelectric, that was a good source of info.  I last flew a Goldberg Extra 300 on and oversized nitro burner and some electrics including a glider.  Flying at 5600 feet cut the power enough that my 300's knife edge loop was more of a "floop". RC flying is a ball, I miss flying with the guys at the Taylor AZ airport Wed. mornings.  That was one sweet deal for the RC'ers! 
Best Wishes,
Bruce M

[Ronmar]

Thats great info Bob, thanks. There are so many vehicles it was used in, and they charge a different price for each of them, so having the vehicle that used the inexpensive one is the trick:)  If it it was a Camaro, I am guessing it probably has a 3.25 OD pulley?  The specs for that pully shows about a 5/8" groove depth so the pully ID is probably around 2"  Running belted off a 24" 6/1 flywheel at 650 RPM, it should spin right around 8000 RPM which is the peak output RPM...   Hmmm:) 

Nice plane.  Havn't flown fixed wing in quite a while(been a rotorhead for a few decades now:))  But some guys I work with have sucked me into flying indoors, and the cool small electric fixed wings are looking like a lot of fun to me...

What are you going to do to keep the noise down on your power plant?

[squarebob]

rcavictim, I have been outstanding in a bunch of fields!!!!

ronmar, the pulley that came with it is 2.6" dia.

[BioHazard]

Did your engine come with that mounting bracket bolted to the bottom of the block? I got the 79cc version of this same engine before they discontinued it. It only has blind holes in the bottom of the block for mounting, I need a bracket like that...