Pulling Power of a Atlas F3

All three powered possibly, just 2 probably not.  You can test with what you have so far (assuming you already have 5 or more cars).  How many cars can single F haul up these grades.  If 5+ then yes, otherwise no.  My guess would be no more than 4 per unit.

One thing that will really help is putting more weight inside of the engine. I install 16-20 ounces using fishing weights. I also  wire the DC motors in sequence for better slow speed performance. 

I think Rdunnii is right.....you will need 3 powered units to pull that train on those grades. 

Do NOT underestimate the drag of the dummy unit.  It is horrible.  It has the drag from the wipers, PLUS all the gears with a very heavy lubricant.  The dummy unit I had would NOT roll down a 3% grade: it just sat there.  Actually took quite a push to make it move.  I had the special B&O set with two A units (one powered).  I had to buy a powered unit and swap mechanisms.  The extreme negative drag of the dummy is such that all units need to be powered.  Sorry to be so blunt.

ray

We have an Atlas F3 AA pair with the dummy as you describe Ray but ours rolls quite easily. In fact, I had not noticed that it had the gears until checking it just now!

Can an Atlas dummy unit be easily powered but adding motors and suitable electronics?

I concur. Doing test runs with an MTH F7 A-B-B-A set with the A-units powered (scale wheels) and a Weaver "express" box car as a transition unit it started slipping on our 1.5% grade when I put on the seventh MTH streamlined passenger car. Now the cars were three-rail, so there was a bit of additional drag, but it's a good indicator that you're in for some slippage without a third powered unit up front.

I have 3 Atlas SD-40s, 2 unpowered and the single powered unit will slip wheels with only a few cars in the train [unpowered units are heavy]

Thanks for the response guys, the answers that you gave is about what I expected to hear. I’m just starting again in “O” 2 rail; I know nothing about the Atlas F-3 and its running abilities, besides hearing that it is a good running engine. I know now when Atlas does do another release of their F-3’s in WP colors I will need to purchase all three powered.

I wanted to purchase the FP7’s that 3^rd Rail released awhile back but didn’t, just because the B’s were not powered. 

You used to be able to order motors from Atlas, but they no longer will sell them (or at least not at the time I was looking).

Powering an AtlasO dummy is very easy to do - if you can find a suitable motor with the right worm on it.  Several years ago AtlasO stopped selling replacement motors as too many people were creating a lower cost option than purchasing factory powered units.  I powered a set of Erie built FM's at a cost of $25 per power truck.

Ed Rappe

Car8534,

Tell Scott of Sunset Models what you wrote here:

"I wanted to purchase the FP7’s that 3^rd Rail released awhile back but didn’t, just because the B’s were not powered."

Maybe, if enough of us tell him, he will offer powered B units.

Ed

I have a stock AtlasO GP7 powered-dummy combination with a stock QSI decoder in the powered unit. The control related CV settings are CV2=35, CV3=CV4=5, CV5=100, and CV25=67 (slightly concave speed curve)

1) The dummy rolls down my 2% grade as soon as I let go of it.

2) The powered unit pulls a train consisting of the dummy GP7 and 15 freight cars up the same 2% grade, at low speed, with no problem. I can also stop and restart the train on the 2% grade. The freight cars are a mix of Atlas, resin, brass and plastic cars. The average weight is probably a little below the NMRA reccomended weight.

Larry Kline