Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

RollBy Speedometer

4690 views
14 replies
1 rating 2 rating 3 rating 4 rating 5 rating
PED
  • Member since
    April 2016
  • 571 posts
RollBy Speedometer
Posted by PED on Friday, March 30, 2018 4:16 PM

I was shopping around for options on a speedometer to assist me in matching locos for a consist. Was considering the AccuTrack II but then I discovered the RollBy Speedometer by Boulder Creek Engineering. Their design is based on a magnet on a single axle and a small circuit board in the car with the axle. The circuit board transmit via Bluetooth to an app on a smart phones or tablet for display. The app can also display distance as well as speed. Details on the bouldercreekengineering.com website.

This approach appeals to me because it shows current speed at any point on the track vs the Accutrack approach which only shows speed at one point when you pass thru their device. I can think of several ways this could also aid operations.

However, this does not appear to be a mass market item and has limited distribution. Available only from Boulder Creek Engineering as far as I can tell.

Anyone here have experience with it?  Comments?

Paul D

N scale Washita and Santa Fe Railroad
Southern Oklahoma circa late 70's

  • Member since
    December 2015
  • From: Shenandoah Valley
  • 9,094 posts
Posted by BigDaddy on Friday, March 30, 2018 4:29 PM

Might as well show it to the folks.  I'm in the construction phase, I have nothing to offer on this, but it's a neat idea.

http://bouldercreekengineering.com/rollby.php

 

Henry

COB Potomac & Northern

Shenandoah Valley

  • Member since
    July 2007
  • From: Yorkton, Sk, Cnd
  • 441 posts
Posted by wvg_ca on Friday, March 30, 2018 6:35 PM

might be as easy to build one, use an Arduino as host   ..

either stationary or mount in an old boxcar ..

not for the 'first build' type though ..

i've done both styles several years back

  • Member since
    March 2015
  • 1,358 posts
Posted by SouthPenn on Friday, March 30, 2018 9:29 PM

A stopwatch and a measuring tape will do what you want. Mark a distance on your track and measure the amount of time it takes to travel from point a to point b. The throttle setting has to be exactly the same for each engine. But that is true for your speedometer setup too.

Most smartphones have a clock/stopwatch app built in.

South Penn
  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Posted by mbinsewi on Friday, March 30, 2018 10:15 PM

I still put both locos on the track, about a foot apart, both with 3 as the address, and see how they run.

Just like the DC days.

I don't have a smart phone, just the flip variety.

Mike.

  • Member since
    March 2015
  • 1,358 posts
Posted by SouthPenn on Saturday, March 31, 2018 9:59 AM

With DCC I put them alongside each other in a yard and adjust them.

With my RailPro engines, once the engines are selected for the consist, the speed matching is done automatically, and on the fly. 

South Penn
  • Member since
    September 2014
  • From: 10,430’ (3,179 m)
  • 2,277 posts
Posted by jjdamnit on Saturday, March 31, 2018 12:17 PM

Hello all,

Sorry, but you lost me at...

PED
...an app on a smart phones or tablet...

For speed matching on my pike (I really don't need to know the scale speed) I use the pursuit method on the oval of the mainline.

I place one locomotive directly opposite of the other on the oval. I set the throttle to the same value and let them run.

I note the difference in time or distance as they pass the starting point.

Then I adjust the "faster" locomotive to match the "slower"one.

If using more than one locomotive in a consist I then use the same method with the "slower" unit and match the rest to this one.

This method is more of a trial and error method rather than using electronic recording devices, but works for me.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

  • Member since
    December 2001
  • From: AU
  • 708 posts
Posted by xdford on Saturday, March 31, 2018 11:24 PM

Hi there,

Have a look at the linked article http://xdford.freeasphost.net/stag09.html and using a 5 second stop watch or timer and you should be able to get a very good approximation of your speed.  The cost virtually zilch and no electronics!

Regards from Australia

Trevor

PED
  • Member since
    April 2016
  • 571 posts
Posted by PED on Sunday, April 1, 2018 9:04 AM

Speed is not the issue other than as a throttle setting reference point. I am aware of many different methods to measure speed. I want to adjust the CV's in each loco so that a specific throttle setting produces the same speed in all loco's in a consist. I am not concerned about speeds as much as I am about adjusting each loco to produce the same speed at the same throttle setting. The only way I know to do that it to adjust the CV's to force the speeds to match at the same throttle setting. In that way, I can set up a consist and be assured that each loco responds to the throttle the same way and they run together confortably.

I am in process of breaking in some N scale Kato F7 units and I have found that two loco's running at same speed (few inches apart) can have very different throttle setting even after a break in period. When I get done adjusting speed settings, I expect those two loco's to run at same speed (or very close) at same throttle setting.

I have a RollBy on order. Since no one here indicated experience with one, I will report back how it works out.

Paul D

N scale Washita and Santa Fe Railroad
Southern Oklahoma circa late 70's

  • Member since
    March 2015
  • 1,358 posts
Posted by SouthPenn on Sunday, April 1, 2018 9:23 AM

Most of my time is spent, with DCC, trying to get the acceleration and deceleration as close as possible and getting them to start at the same time. Sometimes even engines of the same make and model have completely different start-run-stop characteristics. 

I don't run multiple DCC engines with head end power and pushers. Too much of my rolling stock ends up on the floor.

South Penn
PED
  • Member since
    April 2016
  • 571 posts
Posted by PED on Monday, April 2, 2018 9:11 PM

Received my RollBy Speedometer today. Only took a few minutes to set it up so I could experiment with it. Only had time to do preliminary testing but I am very happy with it so far. With it connected to a loco, my iPhone app running and DecoderPro connected to my layout, I was able to ...

1) Do enough testing to verify that I can quickly capture the speed (SMPH) at various throttle settings as my loco traveled anywhere around my layout.

2) Use DecoderProto make some decoder speed table changes on-the-fly to get quick feedback on effect of the changes. With this limited testing, I am sure that I can adjust the speed tables in any way I want. I think I can adjust them such that I can make the throttle setting match the scale MPH.  A throttle setting of 25 would mean that the logo is going 25 SMPH.

3) The only gremlin so far is the track nail problem. This was reported as a potential issue on the RollBy web site. The measuring wheel has a strong magnet on the axle. As the magnet passes over a track nail, the magnetic attraction to the nail is strong enough to cause the magnet to change its rotational speed and cause the wheel to slide a tiny bit. Since the whole RollBy concept is based on measuring the rotation of the wheel set to calculate speed, this blip causes a momentary speed error. However, I think I have a fix. I am using a gondola to hold the RollBy circuit board (fits nicely). I am going to add weight to the car to improve the traction on the wheel. I tested the idea today with a small roll of solder and it helped significantly but it was not as heavy as I wanted. Tomorrow I will pick up some nonmagnetic (lead) weights and try again. I think this will minimize or eliminate the adverse effect of the magnet interacting with the track nails.

I should note that I am using Kato Unitrack with the nails (actually long pins into foam) located down the center of the track. Before someone recommends that I remove the pins and use some other method to attach the track, I do not plan to glue my track down to get rid of the pins.

 

Paul D

N scale Washita and Santa Fe Railroad
Southern Oklahoma circa late 70's

  • Member since
    September 2003
  • 21,320 posts
Posted by Overmod on Tuesday, April 3, 2018 12:12 PM

Use brass pins.

  • Member since
    March 2015
  • 1,358 posts
Posted by SouthPenn on Tuesday, April 3, 2018 2:21 PM

Overmod

Use brass pins.

 

Or aluminum.

South Penn
PED
  • Member since
    April 2016
  • 571 posts
Posted by PED on Tuesday, April 3, 2018 3:57 PM

Brass or Aluminum is a good recommendation. Need to shop around and see what I can find. However, I have been able to overcome this issue to some degree. My RollBy car (gondola) weighed in at 1.1 oz with no added weight. I tried some Pine Derby weights but they were too light. Not made of lead (tin?). Put some lead fishing weights on it and brought the car weight up to 3.1 oz. That pretty much eliminated the steel pin issue but the turnouts were giving it fits. The Kato turnouts have an internal magnet as part of the mechanism and that was too much for the RollBy magnet to deal with. Speed numbers went crazy on every turnout I crossed. This is a downside of doing this on your layout. Only way to overcome that is to make a circle of track with no turnouts. I think I will go ahead and make me a circle track with no turnouts and no steel pins.

Otherwise, I am very pleased with the RollBy performance. My remaining issue is the speed tables in DecoderPro but that is a subject for a different post.

Paul D

N scale Washita and Santa Fe Railroad
Southern Oklahoma circa late 70's

PED
  • Member since
    April 2016
  • 571 posts
Posted by PED on Wednesday, May 16, 2018 8:03 AM

Update - Found brass pins on Amazon so I change all my track pins to the bronze ones and that fixed most of the problems with the layout track. No way to avoid the steel in the turnouts so the speed reading go crazy whenever you cross a turnout. I do have some long straight section with no turnouts so they work good. However, I decided to make a circle of test track with brass pins and no turnouts on a 4x4 sheet of 2" foam and it works great. Also gives me a separate track to break in and test locos

Bottom line - I would recommend the RollBy Speedometer but only if you have a track section with no steel to mess up the magnet.

Paul D

N scale Washita and Santa Fe Railroad
Southern Oklahoma circa late 70's

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!