A smoother running CF7.

[Jez]

I have always been a fan of the Los Angeles Junction Railway - lots of switching operations, modelable industries, Santa Fe (BNSF) and UP visiting locomotive variety and of course the ex-Santa Fe CF7 locomotives.

 

The gutsy CF7s with their raspy EMD 567 BC engines were converted from F3, F7 and F9 locos by Santa Fe's Cleburne shops from February 1970 until March 1978. The LAJ inherited 4 of these locos: 2563, 2568, 2571 and 2619. 2563 was eventually withdrawn and used for spare parts to keep the other 3 locos running.

 

There have been several posts on this forum in regard to Athearn's CF7 offering. Some have been to do with poor or erratic running. So here is a simple, one evening project to give you a smooth, slow running work horse to switch out those freight industries.

 

Items required:

Athearn CF7 (Livery of your choice)

Kato/Stewart F3/F7 or F9. Donor loco should be one of the earlier Kato manufactured offerings.

Kato GP35/SD40/SD45 lighting board

Kato GP35 pick-up wires

0.75 plasticard

Kadee couplers

 

Optional item:

8 pin DCC decoder of your choice. (A NCE DASR or equivalent can be used - you will not need the Kato lighting board if you use this type of decoder)

 

The donor locomotive:

The Kato stamp can be seen on the bottom of the trucks - The earlier Kato manufactured locos for Stewart give the best performance in my opinion, although the later Stewart locomotives can be used.

 

The donor locomotive will need to be disassembled - the motor, trucks and all drive parts are required. The Athearn CF7 will also need to be stripped, leaving just the frame.

 

It is a good idea to strip, clean and lubricate the Kato trucks at this stage. The GP35 pick-up wires should also be fitted, although you can cheat and use the original pick-up wire with extra length soldered on and heat shrink added.

 

The Kato trucks and drive parts are a simple click fit to the Athearn frame:

 

The Kato motor is also a drop in fit:

 

Although you may need to make a 0.75 plasticard motor mount shim to keep all the drive parts aligned:

 

Use the original Kato motor mounting screws to secure the motor to the Athearn Frame.

 

You can also use one of the original Rail Power CF7 chassis/frames - the Athearn shell will fit perfectly and you will probably not need to shim the motor:

 

Continued on next page.

 

Jez

[Jez]

Once everything is aligned, the Kato lighting board or DASR decoder (or equivalent) can be fitted. The original Kato light board mounting screws are used. Plug in an 8 pin decoder of your choice and give the loco a test run:

 

This image shows an Athearn chassis, Kato light board, NCE DCC 8 pin decoder and original Kato pick-up wires with soldered extensions.

 

This image shows a Rail Power Chassis/Frame, Kato light board, NCE DCC 8 pin decoder and Kato GP35 pick-up wires.

 

This image shows an Athearn chassis, Kato light board, Bachmann 8 pin decoder and original Kato pick-up wires with soldered extensions.

 

This image shows a Rail Power Chassis/Frame, NCE DASR decoder and original short pick-up wires.

 

An ESU LokSound V4 decoder also fits perfectly with the round speaker mounted to the roof of the cab.

 

Weight can also be added to the shell:

 

Final assembly once the chassis is running as you would like, is to lower the body onto the frame and secure with the coupler mounting screws. I replaced the original couplers with Kadee 158s (with the trip pins removed), but you will need to use the original Athearn mounting screws:

 

One final thing to bear in mind (I forgot about this) - the truck side frames are incorrect, the outer brake shoes need to be removed as on the left of this image:

 

I hope this tutorial is of use and you enjoy a smoother running CF7.

 

Enjoy,

 

Jez

[Glorious NSE]

'Like'

 

Wonder if that means the Kato parts will fit into old and flaky but good-looking Proto geeps, which were Athearn clones in terms of design. Might give that a go!

[Jez]

Martyn, with a little surgery, the Proto GP30 and GP20 fit nicely onto a slightly modified Kato GP35 Chassis/frame.

 

Jez

[F-UnitMad]

Would a simple replacement of the Athearn motor with a Kato one make much difference? I have my CF7 running pretty well, except that it is a bit jerky on speed step 3 (of 28) for some reason.

I could do with cleaning the Athearn trucks and pick-ups, but didn't want to go to all the trouble of replacement - in other words I have a spare Kato motor/chassis/trucks but it isn't a four-axle loco.

[Jez]

Yes that should work Jordan as long as: the Kato motor has the 4 mounting lugs/screw holes to fit into the Athearn frame and the Kato motor flywheels and Athearn drive parts are the 'Hex' drive type. You may have to look at the electrical pick up system as well to do a bit of hard wiring.

 

Try 128 speed steps too, as that gives for superior slow speed running.

 

Jez

[Glorious NSE]

Jez - my preference would be 28 steps and a degree (not too much) of momentum - impossible to jerk around.

[long island jack]

Jez

 

Ok if you have all those parts to hand,i went down the toothpaste in the gears and cutting a bit of the brushes first to see if that helped.

Worked a treet,my 2 CF7 don't get passed notch 2 so there's not any gear noise,haven't got around to adding sound yet,something else on my "to do list".

 

Ray

[Prof Klyzlr]

Dear Jez,

 

Something I missed early on, is this mech-swap intended for the original RPP CF7 kits on original (gold side, or "super-powered") Ath F7 mechs,

 

or the newer Horizon-era Ath CF7s with can motors?

 

What is the actual issue with the original source mech?

(IE was the problem actually traced to a given set of problem conditions within the stock mech?)

 

Seems an awful lot of "slash and burn" for the Horizon-era units which, at least for me, have run sweetly straight out of the box on analog

(over 12x Horizon-era SW1500s on the roster at last count, and 8x factory stock CF7s auditioned...)

 

That said, I do still have an original RP CF7 kit with donor "super-powered" Ath F7 gold-side mech which could benefit... ;-)

 

Happy Modelling,

Aim to Improve,

Prof Klyzlr

[F-UnitMad]

 

Try 128 speed steps too, as that gives for superior slow speed running.

 

Jez

My NCE Powercab treats 28 steps as being the same as 128 steps...? I just adjust the Start-, Mid- and Max- CV's to suit, rather than a fully customised speed curve - a bit beyond me just yet, that sort of thing...

...oh and I turn OFF BEMF; whatever claims are made about slow running with BEMF, I find the awful buzzing the motor makes far outweighs any benefit.

[Prof Klyzlr]

Dear F-unit,

 

Which decoder arre you using? _Audible_ buzzing suggests that the PWM control of the decoder is using a significantly-low frequency...

 

Happy Modelling,

Aim to Improve,

Prof Klyzlr

[roundhouse]

My CF7 runs fine - I just wish it wouldn't keep blowing Digitrax Sound bugs when I plug them into the Digitrax board.

 

it will be getting a Tsnuami one at some point.

[Jez]

Unfortunately, the vibe I am getting since starting this topic seems to be negative - it may just be me having a bad day. The idea behind the post was to share my experiences in a simple re-motoring project for those of you that may want to have a go. I try to seek as good a running and operating loco as possible - pulling away at a scale 1 mph and watching the coupling tighten one by one is what this hobby is all about for me. If your Athearn/Atlas/Model Power loco runs well out of the box then excellent, but I am sure there are one or two who may appreciate a tutorial on how to tweak an engine to get it to run even better.

 

I am definitely no DCC expert, I only share my experiences of what works best for me.

 

Oh well, at least I now know not to waste my time posting my experiences or ideas on this particular forum.

 

Jez

[alfsboy]

its a very good solution if you have the bits and a problem .My CF7 runs very well in DC and DCC mode .My GP60M however is a pig .Sweet running until you attempt to put the body on.I intend a repower kit probably NWSL or even some NWSL Stanton power trucks if I feel rich .I am fitting ditchlights ,at present and sound at some point and may wire up another unit as they usually run together in switching mode .

Martin

[roundhouse]

Unfortunately, the vibe I am getting since starting this topic seems to be negative - it may just be me having a bad day. The idea behind the post was to share my experiences in a simple re-motoring project for those of you that may want to have a go. I try to seek as good a running and operating loco as possible - pulling away at a scale 1 mph and watching the coupling tighten one by one is what this hobby is all about for me. If your Athearn/Atlas/Model Power loco runs well out of the box then excellent, but I am sure there are one or two who may appreciate a tutorial on how to tweak an engine to get it to run even better.

 

I am definitely no DCC expert, I only share my experiences of what works best for me.

 

Oh well, at least I now know not to waste my time posting my experiences or ideas on this particular forum.

 

Jez

 

Jez

 

Its useful to know as your technique could be applied to other Athearn locos.

 

I had a P42 which ran badly with a sound decoder installed - kept stopping. So this method could be used allbeit with a different length chassis, so i don't think its a wasted posting.

 

Also worth seeing how you fit various decoders and weight the body.

 

Ian

[shortliner]

Jez, You'll never make everyone happy - but if only one person gets a better running loco out of it you will have done someone a good turn - don't be downhearted!

[long island jack]

Jez

Don't get downhearted,i think what everyone's trying to say is why change something thats not broke,if you feel you have to do all these alterations thats your choice.

 

Me personally think it's a cost i can't justify,especialy when i have more than one CF7,and on the lookout for more,if i did the alterations to one,i'd have to do them to them all,especialy if i was using them as a pair for switching.

 

Keep the thread going, as Shortliner said if only one persons follows your example it's been worth it.

 

Ray

[doctor quinn]

Hi Jez,

 

I definitely see some benefit here for me - I've got an Athearn "Blue Box" GP38-2 that I detailed. It looks nice but even after putting a can motor in it sounds like a moter scraper!

 

Just a thought would a Kato GP35 be a suitable donor for an Athearn truck swap?

 

All the best

Nick

[Prof Klyzlr]

Unfortunately, the vibe I am getting since starting this topic seems to be negative - ... I only share my experiences of what works best for me.

 

Oh well, at least I now know not to waste my time posting my experiences or ideas on this particular forum.

 

Jez

 

Dear Jez,

 

My sincere apologies, my comments were in no way intended to denigrate your mech work, or the posting of such. This kind of info is always valuable, and is getting decidely rare in popular Model RRing media.

 

- it's accepted that you found the Ath mech "not up to scratch"

- it's accepted that essentially completely replacing the entire mech (keeping the "pretty bits" by Ath on top ;-) ),

with another achieved your desired operational performance

- and the "how-to" of the conversion is _always_ interesting info.

(I'd heard various rumors of the "plug/clip-in" compatibility of various manufacturers diesel drivetrain components,

I wonder if there's any "compatibility table" info anywhere?)

 

In this context, like a child trying to understand, the question was a simple yet honestly-asked "why?"

 

- If it's because the Horizon-era mech simply doesn't achieve your desired High-performance spec,

(above and beyond "average/generally acceptable performance" levels,

the Horizon-mech rips all over the previous Gold-side can and even-earlier metal-sideframe Ath mech versions! ;-) ),

 

then seeing how you achieved the target "better than average" performance is always welcome.

 

 

- If however, the issues you've identified are due to a _Low_performing loco (IE there's some problem in the motor/mech/drivetrain),

then while wholesale replacement is one do-able solution, a quick-but-thorough diagnostic (and possible discovery of any possible "simple tweak" solutions) on the stock drivetrain would be very useful for many Ath-owners.

 

Again, apologies for any offence caused, most definitely not my intention.

 

Happy Modelling,

Aiming to Improve,

Prof Klyzlr

[Glorious NSE]

I am definitely no DCC expert, I only share my experiences of what works best for me.

 

Oh well, at least I now know not to waste my time posting my experiences or ideas on this particular forum.

 

 

Sorry if what I said gave a 'negative vibe', it wasn't intended to 'get at' you or anyone else. I was just suggesting something else to try that personally I think works superbly and is much easier to use than 128 steps. Just my opinion.

Edited December 19, 2012 by Glorious NSE

[CraigZ]

A stunningly easy swap, Jez. The Kato-into-Athearn is a pretty common swap over here now - sourcing the motors w/ flywheels is the usual obstacle. Frankly it's usually not as easy and neat as what Jez did; there's usually frame grinding involved to clear the flywheels. And care needs to be taken when using the Kato driveshafts as the hex profile that's broached into the flywheel doesn't extend the full depth of the hole. There's a relief cut in the bottom (needed for machining) which means if the shaft is pushed too far that it will disengage from the flywheel. Jez's swap happily shouldn't suffer from this give that the CF7 was built from F7s...the model motor/truck spacing should be the same.

 

And to be honest, the later Stewart non-Kato mechs are pretty darn good too...

[lajrmdlr]

In 1972 the LAJ became wholly owned by Santa Fe Ry. In 1974 LAJ stopped using their 7 ALCO switchers (5 S-2,2 S-4). So Santa Fe let them use CF7s out of their LA pool. Charlie Slater (ex LAJ/ATSF/BNSF conductor) said they were all in Warbonnet paint schemes then. Also in the early years they were all round cabs. So am collecting both the Santa Fe round cab & LAJ angle cab versions that are all the Athearn HO CF7s.

Charlie also gave me copies of all the LAJ Switch Maps. They have a lot of info on all the industries served during his time at LAJ (1970-1984). The maps also include the types, number & frequency of freight cars used. Here's my plan for my first module (live in apartment). It's based on my version of the #19 Horn Lead (attached Switch Map). Some of the industries shown aren't in Horn Lead but wanted more car variety on first module. Also the small yard in lower left corner will be replaced w/ industries when real yard & other leads are built.

Eventually will have 7 leads, a yard plus the Santa Fe's Malabar Yard (for storage) & Vernon Team. That team is right next door to the LAJ Fruitland Team (see aerial map).  

 

[The Bigbee Line]

Jez,

 

I like the idea of the motor and truck swap.  In my opinion the plastic used in their trucks is 'slicker' that that used by Athearn.  Most noticeable with three axle units.  If you run an Athearn SD40 and a Kato SD40 though a crossover the Kato will glide through, the Athearn doesn't have that silky flow....

 

Having said that I tried a more recent Athearn GP-35 (with the scale width hood) and was surprised by the excellent running.

 

Keep sharing your ideas,

[w124bob]

Apologies for the thread bounce, I picked up 2 CF7's at the Crewe meet yesterday for a reasonable price. Both have the Kato conversion but 1 rides a fraction higher by about 1mm than the other. The lower one matches an Athearn CF7 so I assume a small amount of metal has been shaved of the underside of the bolster, am I correct?

[lajrmdlr]

Moved to a downstairs apartment so came up with a new plan . There's sidings (runarounds) on both sides of the layout. Could have 2 people operating the layout, either one on each side or have one operator make up a train in yard, then that train to the switching side. Second person do same thing in yard first then  to switching side. The 2 operators could pass each other on either siding. The bridge will be a plate girder like the LAJ one across the LA River, so not like one shown

Edited October 12, 2019 by lajrmdlr