Repower Athearn H0 CF-7
#16
I'm in the process of building a CF7 (I had an old RPP shell and chassis bought many years ago, before Athearn took them over and now produces their version). I've purchased the same repowering sets from Proto Power West (A-line). Although I've not been running a lot with it yet, I can't see any big problems in allignment and balancing yet (perhaps I'm lucky). I've also used double sided tape to mount my motor (I have also installed the extra motor cradle weight that is available for this model). Now comes the challenge of cramming in the decoder and speaker in this very small loco shell..... On second thought, maybe I should paint it first :-)

Koos

PS: I guess you love your CF7's. Do you have the book : From Cleburn to Everywhere? If not, get a copy, with a bit of luck you can find it on E-bay or Amazon (the US site will probably have it , that's where mine came from, and I am in the UK).
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#17
Maybe a little off topic but several years ago when RPP came out with the CF7 shells, I got a couple of them and also purchased the Overland Models power chassis and hand rail kits from Skokie Valley(???) for them. They came out pretty good and ran smooth as silk, although a bit on the fast side for my tastes. Sold both of them, but this thread has me wondering if I still had one of them how great putting a DCC decoder would make them run. Would have been plenty of room to add sound to them too. That Overland chassis had sprung trucks, a Buhler can motor and was really quiet.

I doubt that Overland still makes the chassis, but perhaps they still have a few laying around or maybe you could find one on Ebay or from some hobby shop that tends to have older stuff still laying around.
Ed
"Friends don't let friends build Timesavers"
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#18
I think flywheels were primarily needed for dc operation to smooth out the operation. If your flywheels are unbalanced, and you are running dcc, why not try it without flywheels? You might need longer drive shafts, but it might run much better in dcc without the flywheels.
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#19
Russ Bellinis Wrote:I think flywheels were primarily needed for dc operation to smooth out the operation. If your flywheels are unbalanced, and you are running dcc, why not try it without flywheels? You might need longer drive shafts, but it might run much better in dcc without the flywheels.
Russ, this is an old thread that did not get updated. I posted in a new thread the solution I used for my CF7. It is the motor assembly from the Athearn Genesis F7. It fits perfect and two of my CF7 run as smooth as Atlas engines. This premium drives has been used under two ATSF shells that have been replaced some weeks ago when the LAJ shells arrived. They are the CF7 that got the working ditch lights.
It is not very economic to sacrifice an Genesis F7 for a RTR CF7 but the F7 have been stored unused in the cellar and the CF7 are in daily use.

However, I did have some problems with an P1K GP15 and replaced the motor with a new motor without flywheels. And in fact there is very little difference. Fly wheels are not "must" for an engine with good power pickup and a DCC decoder.
Reinhard
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#20
Reinhard, I saw the post about the Genesis remotor into a Cf7. I just thought I would post here that a problem with unbalanced flywheels could be resolved by just eliminating the flywheels if you are running dcc.
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#21
Russ Bellinis Wrote:Reinhard, I saw the post about the Genesis remotor into a Cf7. I just thought I would post here that a problem with unbalanced flywheels could be resolved by just eliminating the flywheels if you are running dcc.
You are so very right. With my todays knowledge I would have installed the A-line motors without the unbalanced flywheels and would have saved a lot of trouble.
Reinhard
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#22
Flywheels aren't necessary for DC, either. Wink Goldth

Wayne
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#23
I did find by chance that the Kato GP35 motor (part number 956010, on stock) fits with it mounts and screws perfect into the Athearn CF7. The quality of Kato motors are well known and that is the most easy mechanical repowering possible. You may also use the Kato PBC to keep the motor mounts aligned or do some rework to mount the Athearn PBC on top of the Kato motor. The Athearn bulbs stress the Kato PBC. You should significantly dim them via DCC decoder settings (in my case down to 80 from 255).
Might be that motor fits in some more Athearn RTR diesel engines. e.g. GP38 etc.

ps. The Kato GP35 trucks do not fit. The bolsters are far to low.
Reinhard
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#24
Reinhard - I don't know if this will work for motor mounting, but Lidl occasionally do (here in UK at least) Sticky hook and loop (Velcro?) fasteners which hold up to 15kg, and I wonder if these could be used to hold the motor in position in the chassis. I think they are sold under the name Powerfix The nylon Hook and loop should provide some vibration and sound samping too
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#25
shortliner Wrote:Reinhard - I don't know if this will work for motor mounting, but Lidl occasionally do (here in UK at least) Sticky hook and loop (Velcro?) fasteners which hold up to 15kg, and I wonder if these could be used to hold the motor in position in the chassis. I think they are sold under the name Powerfix The nylon Hook and loop should provide some vibration and sound samping too
I did use a similar kind of flexible glue and double sided sticky tape to mount the other motors. It is essential to prevent the vibrations on the entire engine.
But the amazing thing with this Kato motor is that fit with it's mounts into the Athern engine as if it has been made for it. The other issues like quality and balance of motor and fly wheels or complete solved by the high quality Kato motor/fly wheel/mount assembly.
Reinhard
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#26
Reinhard, do you mind posting a picture of the Kato motor on your CF7 shell? If it fits an Athearn RTR loco like your CF7, then I have good hope it also fits the older blueboxes and other RTR loco's, I recently bought a RTR SD40, and found it has the same motor and motor mounts as the old bluebox Athearns do, so a picture would help in determining if I am right... :-)

Thanks a lot!

Koos

PS: I'm going to have a look if I can get P2K trucks for my CF7... I
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#27
Koos, this is one of the two engines I converted. The old Athearn motor is in the front. You see it is a 1:1 replacement
[Image: IMG_1136.jpg?t=1326400941]

The new motor is mounted with the Kato screws into the original Atheran holes
[Image: IMG_1137.jpg?t=1326400925]

The black motor mounts are very soft/flexible plastic (like rubber). They need to be attached to something like the PCB to keep them aligned.
[Image: IMG_1138.jpg?t=1326400925]

This is my order confirmed today for five sets of motor, bottom screws, top screws and PCB. I plan, as you mentioned, to put them on stock to convert most of the nice but noisy RTR models. It looks like the Kato motor assembly is a 1:1 replacement of the RTR motor assembly.

900040 $1.00 3 Screw 2x7mm, Round Head
900080 $1.00 3 Screw 3x8mm, Flat Head
956010 $35.00 5 Motor with Flywheels and old style Motor Mount
958036 $16.00 5 Circuit Board with White LED Lights

The PCBs are for the lazy boys... But you should get the top screws and make your own PCB and mount it on top of the motor stand to stabilize the soft plastic part. You will need the bottom screws because the Athearn screws will not fit in the Kato motor mounts. Two screws are ok. Be carefully when mounting the motor because the bottom screws shall be used to align the vertical position of the motor. Both drive transmission cams should be perfect horizontal. The noise level will increase if they are not straight aligned.

Just one remark. The Kato PCB can drive the Athearn 1.5 Volt bulbs. But you need to add an additional resistor or dim the outputs with the DCC decoder to at least 40 out of 255 (CV 60 for my Zimo decoders). In one case the front bulbs did not survive. I replaced them with an LED. That is again an 1:1 replacement.
I prefer the Kato motor solution over other quality motors and the A-line sets because they are mechanical a 1:1 replacement with very good vibration isolation and the Kato motor/flywheel assembly is very well balanced in contrast to the A-line unit.

Have fun!
Reinhard
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#28
Thanks so much Reinhard.

I will surely try this out in the near future.

Cheers,
Koos
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#29
I would like to add to remarks

1. The new motors I got from Kato via mail with the new rubber motor mount should/can be installed with the original Athern motor mount screws. Only reused rubber motor mounts need the larger Kato screws. The Athearn screws are fine If you use virgin mounts with unused holes.

2. Kato motors are fine but they are not all the same... One of my five new motors is somehow different and produces more noise than the others when running slow (e.g. coupling) powered by the same Zimo DCC controller. With US internal low shipping cost you might test new motors and ask for replacement of the B rated. To get me right, they are not defect but just not perfect.
Reinhard
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#30
faraway Wrote:... One of my five new motors is somehow different and produces more noise than the others when running slow (e.g. coupling) powered by the same Zimo DCC controller. With US internal low shipping cost you might test new motors and ask for replacement of the B rated. To get me right, they are not defect but just not perfect.

Reinhard, the motor noise may be due to poorly seated brushes. NorthWest Short Line suggests, with the motor disconnected from the drive train, to apply partial power (half throttle or less) and lightly tap the brush-end of the motor housing - the plastic handle of a small screwdriver works well. The motor noise should change, although it may also get noisier. Continue tapping until you get the quietest performance. This may not fully-cure the noise problem, but it's an easy operation to try. I've had good results when installing identical Mashima motors in Athearn switchers - one or two were noisier than the others, but were easily corrected with a few taps.

Wayne
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