Large Scale Central

Bachmann K27

Modeling Rolling stock
#1

I know this has been hashed to death and there is no need to rehash it.
But…
Has anyone come up with a gear replacement for the Bach K-27.?

I have about had it with my gutless wonder.
I’ve had it with the slowdown on my 15’ dia curves.
I’ve had it with it coming to a stop on a .5% (if that) grade and then racing down the other side.

Here’s a test we did this summer on my layout.

Running along side a friends Accucraft K27.
Both units equipped with 14.4 V batteries, fully charged.
Both with Airwire and Phoenix.

He pulled 21 Accucraft cars of various types around without any problems what-so-ever.
I couldn’t pull 6 of the same cars without almost stalling and then racing.

Here’s a test we did on the perfectly flat club’s module last week.
Both charged up.
Both with 5 cars.
His maintained a perfect speed at all times. Mine would slow down in the 17’ dia curves and then speed back up to the throttle setting and then slow down, etc. etc.

I asked him to “full throttle” his K and it speed up to a nice easy scale speed.
Mine took off like a rocket and prolly topped out at scale 60 MPH.

So, has anyone re-geared their Bachmann K?

Barry, is this your next project? If so put me down for a few! :slight_smile:

Rant off.

#2

Some of the reasons why I haven’t bought one. I’ll wait till the bugs are out.

#3

I believe that Mr. Barry is working on that, indirctly (thru 2-8-0 Outside Frame). But please do not bug him as he is up to his ears in work right now. It will come, as I am waiting as well. Of course the other problem is the ‘thing’ is just BIG. If you get one be prepared to go to the D&RGW clearance standards in 1:20.3! While the snow plow is great, it will clear all detail within 10 or 12 scale feet of your track!

Paul

#4

Jphn,

I must be the only person to own one that seems to work. Our club layout has a mainline of +/- 400 feet with only about 80 feet of it straight, the remainder are Aristo 20’ dia. I typically pull a consist of 17-20 cars mixed LGB and Bachmann. Yes, I notice a minimal slowdown going into the curves after being in the straight, and a slight speed up going into the straight. With a constant throttle setting, that would be normal. Curves cause drag, drag slows a train down. Simple physics. Loop 2 is a smaller loop, but has a long 1.5% grade up to the bridges and the same down. Same science applies…slows some up the grade and picks up speed down the grade. But nothing on the magnitude you speak of.

You can view the club layout in the ‘Jordon Lot’ link at www.ecgrc.com.

Bob C.

#5

John.

Does each loco have the same control system fitted?

#6

Tony, John

You bring up an interesting point. I am utilizing track power (22.0vdc - no load) and Aristo Craft Train Engineer. To keep to about scale speed I run at +/- 14.5 volts and about 1.2 amps with the above consist.

Hope this helps.

Bob C.

#7

Tony,
Each loco has the identical control system (as in Airwire).
Both installed direct, as in no factory electronics. Hard wired direct to the motors.
Same battery pack.

I like to run my locos nice and slow. I haven’t caught the Lionel-itus disease yet.
Unfortunately I can’t run the Bachmann K at prototypical 15 MPH.

Bachmann should re-issue this drive train underneath a Lima GS-4 and then it would be perfect. :slight_smile: :slight_smile:

#8

Thanks John.
That eliminates one possible mismatch.

#9

You are all wrong!!

At least thats what we are led to believe. At the Hobby Expo in Chicago, Lynch told me there was nothing wrong with the K27 gear ratio. When I asked why they didn’t maintain the original gear ratio when they changed from a single lead to a double lead worm he got a mite cantankerous with me.

So you see there is nothing wrong with it at all, its just US!

I too am waiting for Barry’s fix. hehehehe

Andre`

#10

I don’t run my trains at warp 5.
I really hate it when I see someone running in a circle at a scale 70 MPH.
The top speed of a K 27 was about 30 MPH.
Even at that speed, it was dangerous.
The average speed of any K series, say, between Antonito and Durango was 15 MPH.

Take a look at Bachmann other models. They have a nice low speed, with plenty of uphill power.
The Annie and the re-geared (Barry’s) Connie are perfect for narrow gauge low speed running.
The Bachmann geared series of lokies, another fine set.

But why this K27? Why does it have to be so high geared?

Like I stated before, Bachmann, put that chassis under a Hudson or Gs4 and you’ll really make the mainline high speed steamers happy.

#11

Hi John,

I have an oval of track set up in a bedroom where I run my K with 11 tankcars and a caboose. Its 8 ft curves and 2 2ft straits on each side, I’m using an MRC ho power pack. All cars have metal wheels, I run with the throtel 2/3 open, no slowing down on the curves. I can also run it around the track at next to stall speed, very slow.
I have also pulled this train with an Annie, a 4-4-0 & afull sized b-man 2-6-0. The K dosent go any faster than any of the other 3. Maybe its the power pack I’m using but the 4 engins all run about the same speed even at full throtel.

Chuck

#12

Chuck,
Then you are the luckiest modeler so far with a Bach K.

TOC won’t even use one on his layout until he comes up with a fix.
And he is (was) the Bachmann Guru.

#13

Hi John,

I wonder why toc dosent put one of the RCS boards in his " Botchman K " and try it out?? Tony W posted a reply to a question I asked about the K taking off going downgrade. He said his controler or board would take care of it, if in fact it does would’nt it do the same for toc’s??, and wouldn’t it make a great selling point for him and RCS??

BTW can’t you slow your K down to a speed that suits you with the Airwire controller??

Chuck

#14

I know of a K that got one of Tony’s PnP controllers installed at the Spring 2008 ECLSTS. The install took about 20 minutes (or less) and worked fine from the start. Its still working fine as far as I know but on a mostly level layouts -
http://www.youtube.com/watch?v=NaQ_K3_t2-c

-Brian

#15

John

How many cells do you have in your K27?

Take a look at the following video

http://www.youtube.com/user/stanames#p/a/0/s-0iUbSXl2s

Two of the K27s in the video are track power and one is battery powered.

There are 12 C cells in the battery powered one and all three locomotives have back-emf motor drives.

If you are having excessive speeds with battery power try removing a few cells.

Hope that Helps

Stan

#16

John,
I know what you are going through with your K-27. On my first K-27 I did the gut the electronics and
just added the Airwire and P-5 to take it to run at the HAGRS show in Aug. I ran it on 20’ curves and no
grades and pulling about 10 Accucraft cars, it did OK. It slowed a very little on the curves. After talking
to Dave Goodsen, on the ones he has done, he put rubber pluming washer on the drivers between the
springs and the bearing blocks.
After the HAGRS show I pulled all 4 driver axles out and removed all the springs. I turned new bushing
on the lathe out of Derlin. This loco also had the bad counterweights so I replaced them at this time and
added magnets for the chuff inputs for the P-5. Added about 4 pounds of lead in the boiler, added a little
weight to the pilot truck and reassembled it. Took it up to Marty Cozad’s and pulled 13 AMS cars with
constantly working the throttle. A few weeks ago I finished phase I of my mainline. It’s over 600 feet
with half of it on 2% grades and another 120 feet of 4% grade. 24 foot or grater curves. I threw 19 AMS
(I tried more but the 19 cars was the limit cause the loco drivers started slipping up the 4% grade)
cars with a AMS shorty caboose on behind it and worked it for about six hours. It was like running a real
loco with always adjusting the throttle going up and down grade. I"m going to order a new G2 decoder
soon and going to see how much that will help. The one loco that I have seen with the new G2 in it ran
a constant speed.
With my 2nd K-27, I’m getting ready to pull the axles and gearbox. I’ll try to regear it by pulling the
worm gear off the motor shaft, put a 15 tooth gear on it. Then run it to a compound gear with a 20
tooth and 15 tooth gears. Then back up to a 20 tooth gear on a shaft with the worm gear reinstalled on
this shaft. I have it worked out in my head and just waiting to get the gears to see if it will work.
I will machine a gearbox out of brass and both the compound gear shaft and the output shaft will
run with bearings on them.

Rodney

#17
Chuck Cole said:
Hi John,

I wonder why toc dosent put one of the RCS boards in his " Botchman K " and try it out?? Tony W posted a reply to a question I asked about the K taking off going downgrade. He said his controler or board would take care of it, if in fact it does would’nt it do the same for toc’s??, and wouldn’t it make a great selling point for him and RCS??

BTW can’t you slow your K down to a speed that suits you with the Airwire controller??

Chuck


Clueless?
Maybe.

All I use is RCS.
Mine doesn’t slow in curves, but I have witnessed (here) another brand that does…BIG TIME.

I do not like the operating characteristics.
I do not like 5 amps full slip.
I do not like 14.5:1 gearing.

NWSL in their .6 mod boxes uses 14.5 or 15:1…but only where it is called out…DIESELS, with driver circumference half that of steamers.

Taking a LS locomotive with a 19V motor and limiting the input to 12V is a stupid workaround.

Read again what the control system you are advocating does in curves.

The RCS has some feedback, and works fine.

But, ANY locomotive in ANY scale that needs back EMF and adjustable criteria to function properly is a piss-poor design.

Note, I said “ANY”, not specifying one or another locomotive.

I wonder if wires and gears are a problem far a certain locomotive at a certain company? (note question mark and lack of specifity)

You run a high-torque 9000 series motor into 14.5:1 gearing, you had better hope and pray some moron somewhere did not install PLASTIC SHEAR PINS somewhere in the drive.

Just hope and pray.

#18
Rodney Edington said:
John, I know what you are going through with your K-27. On my first K-27 I did the gut the electronics and just added the Airwire and P-5 to take it to run at the HAGRS show in Aug. I ran it on 20' curves and no grades and pulling about 10 Accucraft cars, it did OK. It slowed a very little on the curves. After talking to Dave Goodsen, on the ones he has done, he put rubber pluming washer on the drivers between the springs and the bearing blocks. After the HAGRS show I pulled all 4 driver axles out and removed all the springs. I turned new bushing on the lathe out of Derlin. This loco also had the bad counterweights so I replaced them at this time and added magnets for the chuff inputs for the P-5. Added about 4 pounds of lead in the boiler, added a little weight to the pilot truck and reassembled it. Took it up to Marty Cozad's and pulled 13 AMS cars with constantly working the throttle. A few weeks ago I finished phase I of my mainline. It's over 600 feet with half of it on 2% grades and another 120 feet of 4% grade. 24 foot or grater curves. I threw 19 AMS (I tried more but the 19 cars was the limit cause the loco drivers started slipping up the 4% grade) cars with a AMS shorty caboose on behind it and worked it for about six hours. It was like running a real loco with always adjusting the throttle going up and down grade. I"m going to order a new G2 decoder soon and going to see how much that will help. The one loco that I have seen with the new G2 in it ran a constant speed. With my 2nd K-27, I'm getting ready to pull the axles and gearbox. I'll try to regear it by pulling the worm gear off the motor shaft, put a 15 tooth gear on it. Then run it to a compound gear with a 20 tooth and 15 tooth gears. Then back up to a 20 tooth gear on a shaft with the worm gear reinstalled on this shaft. I have it worked out in my head and just waiting to get the gears to see if it will work. I will machine a gearbox out of brass and both the compound gear shaft and the output shaft will run with bearings on them.

Rodney


Be careful.
There are little bitty bearings inside that box.
The box is designed to accept only the gearing they chose.
Barry has been working on this for some time, has the gears now to do it.

If you want to know how to split the driver to access the gear, call me.

I also use nylon washers, on #1 and #4 only (2 and 3 still move), which allows a working chuff position on #4 and keeps the pilot beam from swinging wide on curves with a load.

I don’t have the time to do the gears here myself, so I am waiting for Barry.

Mine comes off the basement floor when someone wants to see it, then back it goes.

If I NEED to run a K-27, the Magnus comes out.

Funny.

All my 2-8-0’s have Barry’s gearboxes in them, all my 4-6-0’s have Barry’s chassis in them.

If it was financially feasible, we’d do the Shay, but it isn’t.

#19

I thought the original comparison was between two K-27’s. One Bachmann, One Accucraft. Both with the same batery voltage and R/C equipment.
If the Accucraft one performs better than the Bachmann one then it is the Bachmann one that is screwed up.
Period.
They are way too fast. Compared to anything. Let alone compared to the correctly geared Accucraft version.
Sure they run smoothly. On the Flat.
Uphill they bog down.
Downhill they tend to run away and require constant handling on the controller.

This is all down to the wrong gear ratio.

#20

Well, for now, there isn’t much I can do about it.
Yes, you have to constantly “operate” the loco.
My friend with his Accucraft does not.
This is fine if you want to drive it like a real one, applying power on the slight grades and backing off down grade.
I’m really thankful I didn’t deliberately make any grades on my layout. Mine are less then 1/2 %, mostly due to ballast settling.
Still, the 1/2 % makes a difference to the Bachmann, not the Accucraft.
After Barry has finished his Connie gear box, maybe, if he doesn’t retire, will develop one for the Bach K.