Tach Reader tape for flywheels

Hi Jon,

 

I don't have them up on my website for download, but I have most of the valid dimensions saved as pdf's.  Send me an e-mail with the stripe width you need and I can e-mail you the file.

 

Dave

Hi Dave,
I down loaded a sound file for a 2-8-0 to a 4-6-2 pacific and i knew the smph would be off but i wanted the passenger station announcments from the 2-8-0
So the engine is running about 7smph faster than all other engines.
Is there a calculation to figure out how many more stripes i need?
If not then a guess is my only answer.
My email is Jon.nestlerode@dejazzd.com
Thanks for the help
Jon

 

Should be proportional. +7 sMPH at what commanded speed? If engine runs +7 sMPH for all commanded speeds you have a separate issue to deal with first.

It's all about gearing and drive wheel size between the 2-8-0 and the 4-6-2 gears and drive wheels,
If i reloaded the original sound file back into the 4-6-2 and scrolled the  DCS thumb wheel to 15 smph i could run multiple engines at this speed on the same loop and they would never catch up or lose any distance between each other.
thanks

Yes there is...

 

 

In your case the "Conversion" engine is the engine you are loading with the new sound file.  You probably don't have the info for the Pacific, but I have a spread sheet from MTH with most of the drivetrain specs for these engines.  If you can post the item number for the Pacific and the item number for your 2-8-0 I can look up the numbers and figure out what the stripe width needs to be to match speeds.  I know Stan doesn't believe this from comments he has made on other threads, but PS2 speed control will be accurate to within 0.1% when configured properly.  Since your engine is running too fast, that means it will need more stripes on the tach strip to match scale speed.  As long as each stripe is over .050" we get it configured to run properly.

Wow Dave looks like you put a lot of work into this!!
The 4-6-2 item no. Is 30-1991-1 this engine is running about 7 spmh faster right now
The 2-8-0 i pulled the sound file from is a 30-4150-1

I also have 30-1337-1 railking triplex  with the sound file from a 20-3069-1 premier triplex that needs to be corrected for speed as well just because i wanted to have a quilable whistle
Anyting you have on these would be a great help
Thanks
Jon

Interesting!  I just put a 30mm tach tape on a 29.57 flywheel ... it was the closest one on the sheet in the Proto2 conversion kit.

Jon,

 

I'll check the numbers on both engines when I get to the NorthWest Trunk Lines tomorrow.  I keep the database there where we do most of our conversion work.

 

Kerrigan,

 

I've seen some of your posts about your first PS2 conversion.  Just so you know, the strips that MTH includes in the kits really aren't designed to match the speed of the engines to scale miles per hour.  There are too many variables for MTH to account for all the possible needs.  I have more than 100 different strips on file for speed matching purposes.  If you want to try and get your conversion matched to scale speed give me the info listed on the worksheet above for your conversion engine and the item number for the sound file you used and I'll calculate the correct tach strip for your engine as well.

 

Dave

Hi Jon,

 

I have some bad news.  To match speeds properly you would need 82 stripes on the tach strip.  That would require a stripe width of only .041 inches, which is too small for the tach reader to detect properly.

 

I have the scale Triplex in my database, but not the Railking version.  However, almost all the Railking articulateds use a 1/17 gear ratio.  If you can give me the drive wheel diameter of the Railking Triplex we should be able to take care of that engine.

Thanks Dave,
Could i at least get the 4-6-2 closer to the correct speed by having .060 stripes?, can the tach reader see those?

I will measure the wheel Dia of the RK triplex this evening when i get home.
Thanks again
Jon

Jon, do the PSA sounds for the 2-8-0 appear on any other MTH engine with different wheel/gear configuration?

Isn't the tach tape also used by the software to maintain a constant speed in cruise control?  That would seem to be an important function regardless of being right on the money in scale MPH.

Checked all passenger sound files for the B and O  pacific engines and none have the same announcements as the B and O 2-8-0  engine from the set.

Yes Jon, you can get closer.  In my experience the practical limit is .050".  I have attached pdf files for tach strips from .050" to .169" in .001"/per stripe increments.  These files are sized to 8.5"x11" landscape.  Anyone is free to download and print them at home.  Just be sure that your printer settings have all "scaling" turned off so the image prints accurately.  Most inkjet and laser printers use ink and toner that is too porous for the tach reader to detect accurately.  After you print out the strips you can trace over the stripes with a ball point pen.  Pen ink is denser and adds luster to the finish which improves readability for the sensor.  I recommend Avery or 3M adhesive backed paper available at any office supply store.

Thanks Dave,
I don't have a 1-2" mic so i used calipers and measured 1.070 Dia. On the RK triplex drive wheels.
Thanks
Jon

Use the .098" tach strip and you'll get a dead on match.

Don't mean to be a pest Dave,
I just remembered i upgraded a Lionel Polar Express with 1.080 drive wheels, i used the sound file for a RK Berkshire with 1.25 Dia drive wheels and of course the speed is off quite abit
Which should i use for this situation
Thanks
Jon

HI Dave,

I did the calculation and came up with 39 stripes .087 width

The Berk has 1.250 drivers, a 15 to 1 ratio and 48 stripes

The Polar Express has 1.080 drivers, a 21.25 to 1 ratio and 1.0815 Dia. flywheel

 

Hopefully you have the same answer

thanks,

Jon

Hi Jon,

 

I just sent you an invite so you can use my tach strip calculator on Google docs.  That will let you do all the calculations you want accurately.  One of the things built into the calculator is that it always rounds to an even number of stripes (counting white and black).  If you tried to apply a 39 stripe tach strip you'd end up with two white or two black stripes touching, which would read as 38.

 

If anyone else is interested in using the calculator send me your e-mail and I will send you an invite to use the Google doc.

 

Dave

Dave,

 

Thank you very much for posting this information!

 

Dave

Dave:

 

Thank you so much!

 

Bill

Hi Dave,
I put the .089 on the Polar Express flywheel, it's better but still running about 9 smph slow, do you think i should place a strip with fewer stripes or more
Thanks
Jon

Hi Jon,

 

You need fewer, wider, stripes.

 

Dave

Dave,
I'm not sure why this didn't come out right the first time but i am going to figure this out for the Polar Express.
The orignal tach strip had 46 stripes and was running 18 smph slower than any other engine, now we have 38 stripes and running 9smph slower, so if i use a tach  strip with 30 stripes this should correct for the gears and drive wheels and run at the correct smph.
Do you concur with this concept?
Thanks
Jon

Hi Jon,

 

With only a couple exceptions, all the PS2 engines have 48 stripes, not 46.  You're on the right path, but I would recommend 28 stripes instead of 30.

 

Dave

Dave,  Is the MTH Spread sheet on drive train specs available.  G

Yes, but on this flywheel i am only using 46 of the 48 stripes
Thanks for your help
Jon

No.

Hi Dave,

I have the Polar Express at an exact smph as other MTH engines, you were right 28 stripes, on the other hand the RK triplex is about 1/2 smph fast, so how many steps do you think I should go, I used .098.

The RK 4-6-2 I used .050 and it is 1 smph fast, but I don't believe there is anything else I can do. the only issue I saw with the tape was at about 60smph the engine shut down, maybe too many stripes for the tach reader, but I got the engine off my layout and was able to start up and run again on a set up track, it seems ok at this time.

thanks for your help!!

Jon

Jon;

I think you will find that it is not possible to make fine corrections like that by changing stripe patterns, given that you can only go up or down in  multiples of 2.

A change of 2 stripes as compared to the standard stripe count of 48 makes a change of about 4 % in speed.

So if you are correcting a speed of 25 mph, you can go up or down about 1 mph.

To reduce speed, add more stripes.

To increase speed, less stripes.

 

Rod