OO Gauge class 71 Electric Locomotive

[DJM Dave]

Right, all this talk of top speeds etc made me go and test mine, and I thought I'd share it with you in this short film.

 

https://youtu.be/ixs3C_kLKv4

 

More than enough speed for my needs, I'd estimate 75MPH, not 90 I know but with my curves LOL

 

What do you think, does any know how I could get an accurate speed?

36ft in N gauge is a mile, so 9ft in 15 seconds is 60mph if that helps?

[mikesndbs]

36ft in N gauge is a mile, so 9ft in 15 seconds is 60mph if that helps?

There must be a formula to work out how fast based on how long your circuit is timed in seconds?

My dad worked out for my old model railway 1171.142/ time = speed in MPH but then he was a very clever man  

[mikesndbs]

Just timed mine of the 9 feet and it took 8.48 seconds??

[Roy Langridge]

Here we go, I can't have an opinion that goes against the crowd.  

If you read the post properly instead of selecting the bits you want to read and then adding some of your own ... you'll learn that cost is no worry to me ... the Hornby one is about the same price and the reason I bought the DJM one AND FOR NO OTHER REASON is because I want the 71 and 74 to be of the same parentage. As it is, it looks like I'll be buying two Hornby 71's and bunging this one in cheap for px. Hows that for saving money?

 

I have not argued against you having an opinion, although you do seem to have honed in on one deficiency (booster) and ignored all the part that are better.

 

What I just can't understand why you didn't go down the hacked Hornby path to start with if that is your preference? There has been quite a lot of knowledge of what the DJ 71 would look like in a showcase, what has arrived shouldn't be a surprise. Indeed you post of 16th May (http://www.rmweb.co.uk/community/index.php?/topic/88264-oo-gauge-class-71-electric-locomotive/page-68&do=findComment&comment=2724441) seemed to suggest you had given up on it already.

 

There is a risk crowdfunded models won't happen.The Class 74 is a crowdfunded model, we knew that when we signed up for it, which you must have done after already committing to the Class 71. So were you happy to have DJ Class 71 before the Class74 was announced? 

 

Finally, as Dave said, the Class 74 is not dead.

 

Roy

[SGP]

 

 

What I just can't understand why you didn't go down the hacked Hornby path to start with if that is your preference?

Listen, let me spell it out. I ordered the DJ model BEFORE the Hornby 71 was even announced. When the Hornby one was announced I decided to go with the Hornby instead as it was a known quantity. When I phoned to cancel my DJ order, I was told that the DJ Model would be released before the Hornby version and that if I stayed on board there would be a 74 to follow. 

I can't see a problem with the Hornby model and because I want to repaint and renumber my 71 ... I'll be better hacking a standard Hornby rather than this DJ limited edition version. Had this been a run of the mill release, I'd be hacking the DJ one right now.

[Mr chapman]

Truly heartbreaking thread It's like an epic party next door your not invited to!

Pleeease shrink one to N! I'll promote the out of it!

[gelboy45]

Truly heartbreaking thread It's like an epic party next door your not invited to!

Pleeease shrink one to N! I'll promote the ###### out of it!

Me too!

Gerry

[DJM Dave]

Me too!

Gerry

Let's get the 17 etc out first lads. Then see ;-)

[Shroomy]

I would just like to say a very massive thank you to Dave

I like the cut of your jib

[Trog]

I like the cut of your jib

 

I did not know he had done a loco for the Spurn Head railway, talk about versatile.

[leopardml2341]

I've had time to hack a 74 from a Hornby 71.

 

Apologies.

 

Is there anywhere we can see the fruit of your labours? Respectfully, I would suggest in a blog or separate thread to avoid distraction herein.

[Budgie]

What do you think, does any know how I could get an accurate speed?

Measure the circuit you are going to run your loco around. I measured mine in millimetres.

 

With a stopwatch (some mobile phones have stopwatch features, if you don't have any other type) time the loco for several laps round your track.

 

Then apply this formula: speed in scale mph = (distance run in mm x 76.2 x 3600) / (25.4 x 65530 x time in seconds)

 

The numbers are as follows: 76.2 is the ratio for OO scale, 25.4 is the number of mm to the inch, 65530 is the number of inches to a mile, 3600 is the number of seconds in an hour.

Edited May 18, 2017 by Budgie

[mikesndbs]

Measure the circuit you are going to run your loco around. I measured mine in millimetres.

 

With a stopwatch (some mobile phones have stopwatch features, if you don't have any other type) time the loco for several laps round your track.

 

Then apply this formula: speed in scale mph = (distance run in mm x 76.2 x 3600) / (25.4 x 65530 x time in seconds)

 

The numbers are as follows: 76.2 is the ratio for OO scale, 25.4 is the number of mm to the inch, 65530 is the number of inches to a mile, 3600 is the number of seconds in an hour.

 

 

Thanks very much.

 

I came to the following but wonder if you could help confirm my thinking please?

 

My class 71 travelled 9 feet in 8.48 seconds so divide 9 by 8.48 to get 1 foot in seconds = 1.061

Edited May 18, 2017 by mikesndbs

[Roy Langridge]

Listen, let me spell it out. I ordered the DJ model BEFORE the Hornby 71 was even announced. When the Hornby one was announced I decided to go with the Hornby instead as it was a known quantity. When I phoned to cancel my DJ order, I was told that the DJ Model would be released before the Hornby version and that if I stayed on board there would be a 74 to follow.

I can't see a problem with the Hornby model and because I want to repaint and renumber my 71 ... I'll be better hacking a standard Hornby rather than this DJ limited edition version. Had this been a run of the mill release, I'd be hacking the DJ one right now.

Fair enough, but when you tell us that the only reason you bought a DJ 71 was the DJ 74, and you obviously ordered the 71 before the 74 was announced, can you not understand our confusion?

 

Roy

Edited May 18, 2017 by Roy Langridge

[Mr chapman]

Let's get the 17 etc out first lads. Then see ;-)

What? I asked you for a model! How dare you not start tooling immediately! What kind of manufacturer are you? You in this for a profit or something?

 

Fair enough... I shall play by your silly rules...

 

But on topic though it's nice to see positive reviews of this model.

[RFS]

I've done some speed testing with mine as mentioned earlier.  I'm using RR&Co Traincontroller, and this builds a profile of the loco (ie speed curve) so that it knows how to run it.  The process involves running the loco back and forth across three block sections and timing how long it takes to cross the centre section, whose length it knows and hence can determine the exact speed.  For the profile it does 15 sample runs backward and forward spread over the speed range, and in the graphs below the vertical access is the speed recorded, and the horizontal access the speed step (1-126). Each black dot represents the speed recorded at that speed step.

 

Here's the first attempt using a Lenz Silver 21 decoder with CV5=254 and CV6=48:

 

 

Top speed is around 56 mph and minimum speed was about 4 mph. You can see the slightly sharper first run whereas the graph is otherwise very smooth. 

 

Not happy with that I tried a Zimo MX634D with CV5=252 and CV6=80

 

 

Surprisingly different performance.  Slow speed is excellent but seriously overdone (it took ages to run, and now the loco starts and stops far too slowly - at speed step 64, for example, it's still only doing 15 mph.  But top speed in both directions is 68 mph. However one unresolved issue with this decoder is that the head code blind lights do not work, whereas they do with the Lenz. I need to revisit the Zimo profile as I'd really like it to be more like the Lenz, ie a smooth progression through the speed steps. 

Edited May 18, 2017 by RFS

[cctransuk]

I've done some speed testing with mine as mentioned earlier.  I'm using RR&Co Traincontroller, and this builds a profile of the loco (ie speed curve) so that it knows how to run it.  The process involves running the loco back and forth across three block sections and timing how long it takes to cross the centre section, whose length it knows and hence can determine the exact speed.  For the profile it does 15 sample runs backward and forward spread over the speed range, and in the graphs below the vertical access is the speed recorded, and the horizontal access the speed step (1-126). Each black dot represents the speed recorded at that speed step.

 

Here's the first attempt using a Lenz Silver 21 decoder with CV5=254 and CV6=48:

 

 

Top speed is around 56 mph and minimum speed was about 4 mph. You can see the slightly sharper first run whereas the graph is otherwise very smooth. 

 

Not happy with that I tried a Zimo MX634D with CV5=252 and CV6=80

 

 

Surprisingly different performance.  Slow speed is excellent but seriously overdone (it took ages to run, and now the loco starts and stops far too slowly - at speed step 64, for example, it's still only doing 15 mph.  But top speed in both directions is 68 mph. However one unresolved issue with this decoder is that the head code blind lights do not work, whereas they do with the Lenz. I need to revisit the Zimo profile as I'd really like it to be more like the Lenz, ie a smooth progression through the speed steps. 

 

I never have all this problem with good old DC - I just like watching the trains go by at a speed that looks sensible.

 

Am I missing something?

 

Regards,

John Isherwood.

[skin_2]

I've got mine now, also the sound decoder from Charlie.  There's loads of fine detail and the overall appearance is very nice. My only gripe is that one of the works plates is crooked and the other one has traces of glue visible, although that's not very noticeable.  It runs very nicely as well but I can't get the headcode light to illuminate, the marker lights come on OK though on F0, and using a conventional decoder (rather than the sound decoder), I can make the cab lights come on using F1 and F2. Am I missing something? Any ideas would be appreciated. Cheers, Keith.

Edited May 18, 2017 by skin_2

[cctransuk]

I've got mine now, also the sound decoder from Charlie.  There's loads of fine detail and the overall appearance is very nice. My only gripe is that one of the works plates is crooked and the other one has traces of glue visible, although that's not very noticeable.  It runs very nicely as well but I can't get the headcode light to illuminate, the marker lights come on OK though on F0, and using a conventional decoder (rather than the sound decoder), I can make the cab lights come on using F1 and F2. Am I missing something? Any ideas would be appreciated. Cheers, Keith.cl71_works_plate.jpg

 

Crooked, yes - but what's with the lettering? Surely the prototype wasn't like this?

 

Regards,

John Isherwood.

[RFS]

I've got mine now, also the sound decoder from Charlie.  There's loads of fine detail and the overall appearance is very nice. My only gripe is that one of the works plates is crooked and the other one has traces of glue visible, although that's not very noticeable.  It runs very nicely as well but I can't get the headcode light to illuminate, the marker lights come on OK though on F0, and using a conventional decoder (rather than the sound decoder), I can make the cab lights come on using F1 and F2. Am I missing something? Any ideas would be appreciated. Cheers, Keith.cl71_works_plate.jpg

 

The head code lights are on function output 3 so you need a decoder with 4 functions.  What decoder are you using?

[Porcy Mane]

Crooked, yes - but what's with the lettering? Surely the prototype wasn't like this?

 

Trump made em do it.

 

 

Pic linked to DJM's zenfolio site.

 

P

Edited May 18, 2017 by Porcy Mane

[mikesndbs]

I've got mine now, also the sound decoder from Charlie.  There's loads of fine detail and the overall appearance is very nice. My only gripe is that one of the works plates is crooked and the other one has traces of glue visible, although that's not very noticeable.  It runs very nicely as well but I can't get the headcode light to illuminate, the marker lights come on OK though on F0, and using a conventional decoder (rather than the sound decoder), I can make the cab lights come on using F1 and F2. Am I missing something? Any ideas would be appreciated. Cheers, Keith.cl71_works_plate.jpg

 

Oh dear, I am glad I can't see that lol

[Budgie]

Thanks very much.

 

I came to the following but wonder if you could help confirm my thinking please?

 

My class 71 travelled 9 feet in 8.48 seconds so divide 9 by 8.48 to get 1 foot in seconds = 1.061

Your class 71 went at 1.061 real feet per second = 80.87 scale feet per second = 55.14 scale miles per hour.

[mikesndbs]

Your class 71 went at 1.061 real feet per second = 80.87 scale feet per second = 55.14 scale miles per hour.

I arrived at that but was too scared to post it lol thanks very much, Hmm bit slow then, maybe in time she will speed up

[skin_2]

The head code lights are on function output 3 so you need a decoder with 4 functions.  What decoder are you using?

Thanks for the reply, I've tried the Legomanbiffo sound decoder and a Gaugemaster DCC27, which says it's a 4 function decoder. It looks as though function 3 controls the forward cab light (F1button), and function 4 controls the reverse cab light (F2 button), but I may have got this wrong of course. I was expecting the head code lights to use F3/Aux 1, but it looks as though it's the forward cab light.