Hey Rodney,
Get looking work, put me down for one of those gear boxes also. Your pictures bring back lots of great memories. I worked 18 years as a machinist and supervisor in the aero space industry. I would love to have a lathe and small mill in my new shop, but right now I’ll just have to settle for my CNC Router. Can’t wait to see how this all pans out for you.
Chuck
Nice work Rodney…
Unlike Chuck I have CNC nothing…I can only wish
Bruce
I’m back as long as I don’t spend all my time on this computer. There is a
lot of work for me to get done now.
Ric
I still think I’m just a dumb old truck driver that likes to play with trains and my machines.
John
No, Barry will not a customer. I want him to check it out and then give his comments
on it, the good and the bad.
Kevin
I have you down for one.
Joe
Thanks for computing the gear ratio
Robbie and Bob
The K is very easy to take apart to get to the motor
I will do some photos for you.
Terry
Got you down for one
Chuck
One for you also
I need for you to come spend some time with me
I took a HF mini mill and converted it to CNC over 2 years ago and it
has not made a chip yet. I cannot figure out cad so there it sets.
Now if I had that running, these gearboxes would be fast and easy.
I went to Vo Tech in high school to learn the trade and what do I end
up doing for a living??? Driving a big truck
David
Thanks for your comment.
Right now I have 20 for sure that will take one. On this first batch, I would like to
install the gearbox on your motors myself to insure that this test batch is done right.
Tony Walsham and Barry will get just the gearbox. I will send Tony a e-mail and talk
to Barry on the phone to take care of them.
After this “test” batch, I’m guessing the price to be somewhere between $90 and $120
for the gearbox and another $10 if I do the install on your motor.
After this test run, I will be able to figure the time and materials that I have in them
and give a firm price.
The price for the “test” batch will be $75 and that will include the shipping the motor- gearbox
back to you. I guess the easiest way for me to do this is to have you send me a e-mail for
confirmation. I will send you a return e-mail so you know that I got it.
My e-mail address is: [email protected]
Thanks everybody
Rodney
Then at this point I suppose you can put me on the list, pending parental approval.
I really dig the machining, considering I’m in the middle of a all-metal loco build myself. Even I’m not crazy enough to cut my own gears 
Nice work Rodney. If I decide to ever get a K I will contact you for the up grade. Later RJD
Please put me down for one for my K also. Since my RR is still in planning awaiting right of way approval (wife says her Japanese garden has to be finished first…) I can wait for the production group.
thanks!
Well, I’m standing there at the Bridgeport making parts and wild hair brain idea just hit me.
Using this exact same gearbox I can change the gear ratio by changing the gears in my gearbox.
By changing the 24 tooth gear to a 25, and the 18 tooth gear to a 17, The final gear ratio is 31.35 to1
Changing the 24 to a 19 and the 18 to a 23 the final ratio is 21.24 to 1.
As I said this is using this same gearbox.
I do not have a indexing head (spending another $500 going to hard to explain to the wife) to cut these
other gears right now, but I will get one ordered soon.
So that means if you have one of these gearboxes and your K is too fast or too slow, all you got to
do is call and I will have a set of on the way to you or I will change them out for you for the cost of
the gears and shipping.
I want to thank Joe Satnic for the gear ratio formula. You explained simpler that my machinist
handbook does.
Rodney
Refresh my memory.
What’s the gear ratio out of the box?
John
The stock K is geared 14.5 to 1
Rodney
Got a e-mail and was talking about battery voltage. I know Steve Stockham has a 14,2 battery setup
in his. Now with this new gearing available, I think the 21.24 gearing would enable them to leave their
battery setup as is, and still see a vast improvement over the stock gearing. This will be a instering
how it works out.
Rodney
The real speed may not actually change very much.
The current loco ratio means that 14.4 volts makes it a slot car on flat track. So the actual voltage required for a realistic top speed is less than 14.4 volts. Meaning the 14.4 volts is not actually being used.
Raising the ratio number and lowering the top speed increases the torque going to the drive wheels. Therefore the amount of voltage required for a realistic top speed will increase and 14.4 volts will probably be about right with a ratio of 26:1 or thereabouts.
I would respectfully suggest we test it to see what happens before getting onto the variable ratio merry go round.
Rodney,
Please put me on the list for one of the conversion gearboxes.
Thanks
Andre`
Rodney,
Why cut 4 different gears ($$$$) when just 2 ($$) may very well be satisfactory?
Will you be able to match the (sum of the 2 new) radii to the sum of the 24t and 18t radii?
Sincerely,
Joe Satnik
I have the very first K-27 I converted to battery R/C back here to tinker with as long as is necessary.
The new owner has three K-27’s, so, if this new gearbox addition works successfully I have two more to do for him. Plus another dozen or so for others.
Fingers are crossed.
At the same time he wants me to rip out the old Elsema based R/C hardware and install my new PRO series in its place.
Joe
Right now I need to get out there and see how it performs across the board. I think in the end, this
is going to be the ideal ratio of them that I posted.
Tony
That good to here.
I have a gentleman coming up tomorrow with 2 motors for a install. With the nice weather we
are having, he wants to run them on Thursday. So we may have some live real feedback real soon.
Had a big setback Monday with tolerances caused by the cheap calipers I was using. Went out and bought
2 Mitutoyo’s today and started over.
Rodney
I did some testing on my layout today as I am really concerned about the Derlin gear slipping
on the shaft. I could go with a tighter fit but then I might have the same problem the connie
suffers from of the gear splitting. I hooked up a 18 volt battery and at full throttle
it still ran at a pretty good pace. 70% throttle was a nice fast pace so I think this is going
to be very good all around ratio. Noise wise, it does make a slight whine, but with the sound
on I could not hear it then. Then I did some weight pulling up the 4% grade. Using
Accrcraft gondolas I added 50 lbs of lead to them and headed out to the grade. On the flat
it started very nicely and and pulled the grade with no wheel slippage. I stop on the grade
and restarted. a little slippage, but it got going OK. I did this a few times. My fear was right.
The Derlin gear started slipping on the shaft. So I am going to stay with all brass gears till
I find a solution for the gear slippage. I will replace the gears in this box and do some more
testing with 14.2 volt battery. I have asked a friend to come up and shoot some video and
will get it posted when that happens.
Progress on the is continuing and almost half done with test batch.
Rodney
I install a gearbox for a local gentleman and here is his first impressions of it.
"Got the loco setup and running…First impressions:
On the box I was testing, I reinstalled the Derlin gear and applied some red loctite and let it cure about 2 hrs
and did some more testing, pulling the 50 lbs lead in the gons. Got to run it about 1 1/2 before it got too dark.
The fix seems to be working for now. I will continue tomorrow if it does not rain.
Rodney
The low speed control of the K-27 has always been very good. I would expect a more correct ratio would make it even better.
I ran your idea past Gordon Watson (Argyle Locomotive Works) who thinks an add on primary reduction gearbox, rather than replacing the existing gearbox, is a really neat idea.
Keep up the good work.
Tony
The way he explained slow to me was about 4 ties a minute and was very smooth.
Rodney
I have fixed the Derlin gear slipping problem. I’m making hubs for the gears that will be a press fit
and it will also be pinned to the hub.
The machining is complete on the first 10 boxes and working on the next 10.
Waiting for some more supplies to come in.
Rodney