Large Scale Central

K-27 Driver-to-Driver Distance

Modeling
#1

I’m thinking of bashing a Bachmann 4-6-0 to a 2-8-0 and I was thinking of using a set of Bachmann K-27 drive rods.

my question is , does anyone know the driver-to-driver distance measurement for the K-27? And, is the distance between all drivers the same?

Thanks.

Adam

#2

Barry Olsen had a conversion kit to turn the 10 wheeler into a 2-8-0. Maybe he can answer some of your questions.

#3

Thanks David,

I’ve seen his phone number published here before. I’ll do a search and perhaps give him a call.

Thanks again.

Adam

#4

Adam Dziuk said:

Thanks David,

I’ve seen his phone number published here before. I’ll do a search and perhaps give him a call.

Thanks again.

Adam

#5

Thanks Joe!

I’ll give him a call.

Adam

#6

Adam,

There is a post elsewhere on this form that says that Barry Olsen is in the hospital.

#7

Thanks again Joe,

Funny thing, I pulled out my phone and was about to call Barry when I decided to pull up this thread to confirm his number and address.

The first thing I saw was the post from Ken.

I hope the best for Barry.

Adam

#8

does anyone know the driver-to-driver distance measurement for the K-27?

There are plenty of drawings online, and the Bachmann is a decent model so I suspect it is fairly accurate.

http://tumbledowncreek.com/www/K-27_.html has one and it shows 45"+48"+45"

#9

Thanks Pete,

That’s exactly what I was looking for.

Not as symmetrical as I was hoping for but after I do some calculations it just may work.

The K-27 drivers are 40" 1:1 that’s about 1.97" 1:20.3. The 4-6-0 drivers are 2" So, if the distance between the front pair and rear pair of drivers are 45"in 1:1 that’s 2.21"in 1:20.3. That leaves me .21" between the treads of the drivers, one with a flange and one with no flange.

Now I have to measure the flange height of what will be my front and rear drivers. my 2 middle drivers will be blind drivers, there should be plenty of room between them.

Thanks again. I think I have my answer.

Adam

#10

Pete Thornton said:

does anyone know the driver-to-driver distance measurement for the K-27?

There are plenty of drawings online, and the Bachmann is a decent model so I suspect it is fairly accurate.

http://tumbledowncreek.com/www/K-27_.html has one and it shows 45"+48"+45"

Not my cup of tea but I like learning history. However I get confused on the timing systems …Is that a Baker or Walsherts ?

#11

Rooster said:

Not my cup of tea but I like learning history. However I get confused on the timing systems …Is that a Baker or Walsherts ?

I think it’s a Baker.

Adam

#12

Adam,

I started a model of EBT #3 many years ago using the Bachmann 4-6-0 wheels and motor, of which I seemed to have many. The frame was conventional 1/16" x 1" brass strips with slots for the 4-6-0 wheel bearings. The middle wheels (blind) were allowed to float up and down and didn’t add much to the traction, (they could have been sprung.) The front wheels were in a frame that pivoted along the length of the chassis, allowing the frame to tilt in true equalized fashion. Let me know if you want more.

#13

That’s pretty cool Pete, Lots of good ideas.

I’ve ordered a set of K-27 drive rods from Bachmann, when they arrive, I’ll sit down and start laying out the chassis.

I like your Idea about the pivoting front wheels and sprung blind middles. Now you made my build more complicated. Haha

I think I’ll take the extra time and do this right.

By the way, I’m not modeling anything specific. I just want a 2-8-0 on my roster and I have most the parts already.

Thanks Pete.

Adam

#14

when they arrive, I’ll sit down and start laying out the chassis.

The usual process is to solder the frames together, mount them securely on the frames and drill all 4 (2 frames, 2 rods) at once. If you already have holes in the rods, then use one rod and drill both frames at once.

Here’s a couple of other photos I found. I don’t know why the blind drivers are on the front frame - maybe I was testing !

#15

Smart!

I had thought about screwing both frames together, laying one side out and machining both at the same time. But a little solder and then everything is nice and flat.

And using the drive rods to locate the axle centers, sure beats using a micrometer!

I see from the construction of your front frame that you, like I, must be running battery power. I was toying with the idea of insulating the left from the right side so I could also run this on someone else’s powered track without shorting everything out(https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-surprised.gif)

But you know what, I have yet to run my trains on someone else’s layout. And if I decide to, I’ll just take something else.

This project is something I’ve been kicking around for a while, now I’m getting amped up about it.

Thanks for the good advice Pete, very helpful.

Adam

#16

Well, if you are using wheels where one is insulted from the axle, you just need to make sure that you use the insulated ones all on the same side. The entire frame could be hot, but if its not electrically connected to the wheels on one side, you should be ok.

#17

Hi David,

If I remember correctly, the Bachmann drive wheels that are on the generation 6 chassis, that I will be using. The axles are insulated from the center of all the wheels, but the bearings (bushings) between the side frame and wheels make the electrical contact. The bearing is held in the plastic side frame and the metal wheel hub rotates inside. Then there is a copper pickup that lays on top the bearings and direct the electrical flow to the motor, etc. In other words, if the bearings on the left side make contact to the bearings on the right side, BAM, you’ve got a dead short.

Thanks anyway David, That’s why I was was a little hesitant about building this with brass side frames that are connected electronically to each other.

Adam

#18

I see from the construction of your front frame that you, like I, must be running battery power.

Yes, I had a tender all set up on my 4-6-0 with rx and stuff, but I sold the 4-6-0 and this project ground to a halt.

There are solutions to the insulation - use plastic or nylon blocks between the frames, and make a nylon block for the front axle frame.

The pickup issue isn’t quite that simple. The driving wheels have a nylon insert (see pic) and I assume power goes from the screw holding the wheel to the axle and then to the bearings. Some judicious insulation on the screw and you might manage to insulate one wheel entirely. (I assume you know how to dismantle the wheels? Poke a screwdriver behind the wheel counterweight and push the plastic insert out - then all is revealed.)

#19

Pete Thornton said:

(I assume you know how to dismantle the wheels? Poke a screwdriver behind the wheel counterweight and push the plastic insert out - then all is revealed.)

Yep, did it many times.

I even put them back together.(https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-smile.gif)

The one problem I’ve found with the gen. 6 Bachmann chassis is, after extended running, the wheels loosen on the axles. The screws don’t necessarily come loose but the nylon bushings (insulators) compress and become deformed. to remedy this I put a small, slightly larger diameter, washer between the screw head and nylon. If the washer is to large it will touch the wheel and cause an electrical connection to the axle.

But, I run battery power and I don’t run on anyone else’s layouts. So, it wouldn’t be a problem for my empire(https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-undecided.gif). My railroad wasn’t built to run track power anyway so we’re even.

Merry Christmas all!!

Adam