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Rapido Q/A
Jun 29, 2020 19:23:57 GMT -8
via mobile
Post by llxlocomotives on Jun 29, 2020 19:23:57 GMT -8
This probably belongs elsewhere, but I am responding to questions about my post on this thread.
My statements about the performance cost of DCC modules come from several back to back tests where the only change was the addition of the module. The modules examined were from NCE, Lenz & ESU. The Units were tested on both DC & DCC as appropriate. The modules were set to use the factory settings.
In this situation several things surprised me. By measuring the track voltage when the supply is set at 12 volts and determining the DCC speed step that replicated that voltage, you can compare the performance of the modules on a controlled DC signal & the DCC signal. The DC supply is a fixed DC voltage with no PWM.
When those cases are compared, module in place, The performance results are basically identical. The module provides a PWM to the motor at low voltage(speed steps). as expected, the engine sustains movement at a low voltage setting. The unit crawls at a very low scaled velocity. This is the primary performance benefit of the DCC module. The same engine without the module starts at 2 to 3 volts higher voltage at a sustained velocity that is 5-10 smph higher then with the module. In reality this is similar to the benefit that adding PWM to old DC transformers. Clearly the module gives the added benefit of independent control. The cost shows up at the high voltage side. Even though the engine with the module starts at lower voltage, it’s velocity at the equivalent 12 voltage setting is significantly slower than without the module. For the NCE module it takes an additional 1.5 volts to achieve the no module speed. For the Lenz & ESU modules, it never achieves the no module 12 volt velocity. It looks to require 2.5 to 3 volts to achieve the velocity. The inference is that the motor is seeing that much less voltage at An equivalent track voltage. That means that intentionally or unintentionally, the module is creating a voltage loss to the motor. Thus we see a loss in velocity and a reduction in draw bar force at the maximum power point. This can result in the loss of several cars in train length.
I have repeated these results with several of each type module, except the ESU, which I had only one. I did not attempt to modify the decoder from the factory settings. So not sure if so if this could have been mitigated the results.
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Post by edwardsutorik on Jun 29, 2020 20:00:48 GMT -8
By measuring the track voltage when the supply is set at 12 volts and determining the DCC speed step that replicated that voltage, you can compare the performance of the modules on a controlled DC signal & the DCC signal. The DC supply is a fixed DC voltage with no PWM. I am concerned with the phrase "determining the DCC speed step that replicated that voltage". I suggest the proper comparison is a DC unit at 12V DC and a DCC unit at the highest speed step. Both of these represent wide-open-throttle under each system. Ed
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Post by Paul Cutler III on Jun 29, 2020 21:42:12 GMT -8
amtrakfl9, I have 5 Rapido FL9's and they average just under 60 mph (some more, some less...roughly 1 foot per second). At my club, I installed a scale speedometer which is quite accurate and I measured each one. The Rapido FL9's are a little slow as the NH's top speed was 79 mph (and 70 mph west of NH)...but they aren't 45 mph slow. The Amtrak F40PH's were carded for 110 mph in the pre-Acela days here on the NEC in Massachusetts and Rhode Island (where the Acela does 150 mph today). llxlocomotives, I believe the issue here is that DCC is a square wave AC signal. Every decoder uses a wheatstone bridge to change the AC to DC for the motor, and that always takes off 1.5v due to the diodes in the bridge. So when you put 12vac DCC to the rail, the motor is only going to get 10.5v max. That's why most Digitrax systems put out 14v to the rail; you'll lose the 1.5v and probably lose another 0.5v due to voltage drop, which means you'll get about 12v (more or less) to the motor at top speed. BTW, the Digitrax Zephyr systems only put out 12v as this is what N-scale uses (the Z has no voltage switch). I have a Zephyr at home while my club uses DB200's at 14v. I always have to set my bulb headlights to be kinda dim on my home system so they won't be too bright on the club layout.
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Post by jonklein611 on Jun 30, 2020 4:24:21 GMT -8
By measuring the track voltage when the supply is set at 12 volts and determining the DCC speed step that replicated that voltage, you can compare the performance of the modules on a controlled DC signal & the DCC signal. The DC supply is a fixed DC voltage with no PWM. I am concerned with the phrase "determining the DCC speed step that replicated that voltage". I suggest the proper comparison is a DC unit at 12V DC and a DCC unit at the highest speed step. Both of these represent wide-open-throttle under each system. Ed Agreed, Anything below speed step 128 / 28 would have PWM applied. You can also adjust Vmax via the decoder.
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Post by amtrakfl9 on Jun 30, 2020 23:41:31 GMT -8
amtrakfl9, I have 5 Rapido FL9's and they average just under 60 mph (some more, some less...roughly 1 foot per second). At my club, I installed a scale speedometer which is quite accurate and I measured each one. The Rapido FL9's are a little slow as the NH's top speed was 79 mph (and 70 mph west of NH)...but they aren't 45 mph slow. The Amtrak F40PH's were carded for 110 mph in the pre-Acela days here on the NEC in Massachusetts and Rhode Island (where the Acela does 150 mph today). My two top out at 45-50 mph with a train. They might be able to hit 55 or so running light, but that isn't much use unfortunately. Maybe that's a DCC voltage difference thing, but regardless even the high 50s range that you report is really not enough for a passenger diesel in my opinion. I've only seen F40s allowed 100 in employee timetables, but I have heard rumors that a group of them were geared for 110 at some point in the 80s and assigned to the northeast. By the mid 90s though this appeared to no longer be the case.
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Post by llxlocomotives on Jul 1, 2020 5:56:03 GMT -8
While it does not directly address the issues, this www.llxlocomotives.com/wp-admin/post.php?post=1905&action=edit compares the three Radio engines I have tested with a number of other engines. I do not take questions on that site. I will take them here. My DC to DCC comparisons are else where. I am in the middle of running a 15 engine test series on that subject. Some will compare DC, DCC & Railpro(fixed DC). Speed is only one of the things I’m looking at.
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Post by Paul Cutler III on Jul 1, 2020 6:12:42 GMT -8
amtrakfl9, We're running Digitrax DB200's set at 14v. Track voltage through the speed trap of the speedometer is around 13.5v. Next time I'm there, I'll test run each FL9 and post the results here.
In the 1990s before electrification, Amtrak was running the "New England Express" trains here on the NEC. These were strictly limited to 4 cars (3 AmCoaches, 1 AmCafe) and 1 F40PH. Amtrak had an on-time promise that if they were "late" (that's more than 15 minutes in Amtrak time), you'd get a refund on your ticket. Perhaps these trains had the 110mph F40PH's? Anyway, the "New England Expresses" were changed back into regular corridor trains when electrification construction started to impact on-time performance.
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leikec
Junior Member
Posts: 95
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Post by leikec on Jul 1, 2020 16:39:24 GMT -8
I wonder what kind of passenger train speeds the DL-109's were doing in their heyday...
Jeff C
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Post by Paul Cutler III on Jul 1, 2020 16:54:56 GMT -8
Jeff C, The DL-109's first arrived on the NH in Dec. 1941 as the very first diesels to be designed to be dual passenger and freight locos. As such, they were geared for 80mph max speed. This suited the NH just fine as their MAS (Maximum Authorized Speed) east and north of New Haven, Conn. was 79mph anyways. Their max speed can be seen here in this diagram (on the data table on the right). www.alphabetroute.com/nynhh/dieseldgms/0700-0709.pdfI don't know what the other DL-109 railroads had as max speed for their units. The NH PA-1's, BTW, were geared for 90 mph. The first two NH CPA-24-5's were built for 107 mph (these were the demo units) and the remaining 8 units were built for 90 mph. FL9's were geared for 89 mph. The NH hood units were 80 - 83 mph, with the exceptions being RS-1 (60), RS-2 (65) and U25B (70).
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leikec
Junior Member
Posts: 95
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Post by leikec on Jul 1, 2020 17:01:03 GMT -8
Thanks, Paul. What took you so long? The NH DL-109's are rapidly moving up on my favorite locomotive ladder. Jeff C
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Post by edwardsutorik on Jul 1, 2020 17:06:04 GMT -8
I do wish the DL-109's and the passenger F-M's were brought up to Proto/Genesis standards.
Ed
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Post by carrman on Jul 1, 2020 20:17:41 GMT -8
Btw, I had a motor failure in less than two hours running on one of my RS11's. All 4 are in Rapidos hands right now.
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Post by llxlocomotives on Jul 2, 2020 5:36:44 GMT -8
Another motor failure. Can you describe the particulars? Were you running on DCC? Did you do any break in running? What kind of trains were you running? If it was running on DCC did you check the CV’s to be sure they were at the values that they recommended for the RS-18? Out right motor failures are pretty rare for these motor types. Rapido seems to have seen their share recently. These out right failures are usually due to a break down of an internal part, bearing, brush, etc. That is usually only caused by too much heat in normal running. That can be due to a seized drive line or excessive voltage. Too much transient voltage (PMW) at a high average voltage will also cause the motor to run warmer than normal. If this is the same model motor that was used in the RS-18, the basic motor is sound. Out of curiosity I have run one of these through more than 50 hours of severe running conditions. The performance measurements have not changed. This was done with my lab DC supply, so there is no signal ripple of any kind. Curious to here what the running conditions were before yours failed.
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leikec
Junior Member
Posts: 95
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Post by leikec on Jul 2, 2020 10:17:18 GMT -8
I do wish the DL-109's and the passenger F-M's were brought up to Proto/Genesis standards. Ed Me too! I think I've got at least one picture of a NH DL-109 and a FM Cab unit working together on a train--not sure if the NH DL-109's ever were photographed in a train with other Alco locomotives. I have a lot to learn about New Haven operations and timelines, which is why I appreciate guys like Paul so much. Jeff C
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Post by Paul Cutler III on Jul 2, 2020 13:00:04 GMT -8
Ed, Bringing the DL-109 up to Rapido/Genesis standards would be, um...expensive. Each railroad version was different, and even the NH ones were not all the same. I'd love to see it because it's such a NH engine, but I'm not holding my breath. Jeff, Yes, the NH ran their DL-109's with CPA24-5's and PA-1's. In fact, one DL-109 (0727) was turned into a B-unit of sorts specifically to operate with a pair of PA-1's on the Merchants Limited. It kept the cab and the controls, but they added a vertical door to the nose (and nose MU) to the unit to allow crew members to move between units at speed. 1.bp.blogspot.com/-SCJaxtRhvoE/VsyoPUlj6KI/AAAAAAAAAnU/rs5zhgtBytI/s1600/Lewis%2BWalter%2B1954.jpg It's a crazy looking engine even for the NH. And thanks for the mention! If you haven't already, you should join the NHRHTA where we have all kinds of info being put into our semi-quarterly Shoreliner magazine, and of course, our own free internet forum at nhrhta.org were NH questions can be asked and answered.
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Post by carrman on Jul 2, 2020 16:29:54 GMT -8
Another motor failure. Can you describe the particulars? Were you running on DCC? Did you do any break in running? What kind of trains were you running? If it was running on DCC did you check the CV’s to be sure they were at the values that they recommended for the RS-18? Out right motor failures are pretty rare for these motor types. Rapido seems to have seen their share recently. These out right failures are usually due to a break down of an internal part, bearing, brush, etc. That is usually only caused by too much heat in normal running. That can be due to a seized drive line or excessive voltage. Too much transient voltage (PMW) at a high average voltage will also cause the motor to run warmer than normal. If this is the same model motor that was used in the RS-18, the basic motor is sound. Out of curiosity I have run one of these through more than 50 hours of severe running conditions. The performance measurements have not changed. This was done with my lab DC supply, so there is no signal ripple of any kind. Curious to here what the running conditions were before yours failed. Running on Digitrax DCC, working a small local, 8 cars or less. No more than speed step 15 on the DT402D throttle. Unit began slowing down, and then stopped and just sat there and shuddered all the while making the regular noises for a sound unit. Hood was warm, engine smelled of hot electricals. All four spent an hour running on a break in train with now problems. I did not check CV's as Rapido said all the RS11's had the CV's set before shipment.
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Post by llxlocomotives on Jul 2, 2020 17:34:12 GMT -8
Thanks for the description of the failure. So it was running slightly over half the voltage range. The problem is on the mobile side of the decoder, the sound program continued running. Did you see any smoke to go with the smell? How much investigating did you do.after? Do you know for sure the motor failed. That is hard to know unless you pull the shell.
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Post by carrman on Jul 2, 2020 17:38:51 GMT -8
Thanks for the description of the failure. So it was running slightly over half the voltage range. The problem is on the mobile side of the decoder, the sound program continued running. Did you see any smoke to go with the smell? How much investigating did you do.after? Do you know for sure the motor failed. That is hard to know unless you pull the shell. RS11's are losing motors like no tomorrow. They have replacements of an improved kind. I contacted Rapido and sent them all back.
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Post by Paul Cutler III on Jul 2, 2020 23:33:15 GMT -8
amtrakfl9, Well, I ran all 5 of my Rapido FL9's Thursday night. I found one error in my earlier post: the no-load DCC track voltage through our speed trap is 14.5v, not 13.5v. The voltage was measured with an RMS meter, so it's a true voltage reading (again, without a load).
After a few passes to warm up the motors, my FL9's all ran 58 to 65 mph individually (no train). Some ran faster backwards or forwards, others were equal in either direction. The speed trap area has no grade.
I then put 14 passenger cars behind a pair of FL9's. The cars were 6 Rapido 8600 coaches with the original trucks that don't roll that well, 5 Rapido parlor cars with very free rolling trucks, 1 Rapido diner, and two Soho brass cars (Obs and County car). There was no difference in speed with two FL9's.
Next, I used the same train with just one engine. When starting, the FL9 wheels slipped pretty badly but the train started and got up to its max speed. The result was that the top speed was about 10 mph slower with one unit. I would say that I had almost maxed out the pulling power; there's no way it would have climbed any grade with that train.
How are you running your FL9's? Singly with a bunch of cars? And what's your track voltage?
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Post by Judge Doom on Jul 3, 2020 6:22:16 GMT -8
Thanks for the description of the failure. So it was running slightly over half the voltage range. The problem is on the mobile side of the decoder, the sound program continued running. Did you see any smoke to go with the smell? How much investigating did you do.after? Do you know for sure the motor failed. That is hard to know unless you pull the shell. It's a problem with some more recent Rapido releases on DCC, something with the interactions between the newer ESU decoders and their settings, the onboard circuit board, and the motor used, that over time (or in a short period of time) degrades the performance of the motor. Rapido had announced recently they were switching to coreless motors on future product releases, and also working with TCS on a jointly developed decoder (see their video at ). The Royal Hudsons were also affected by this, but by accounts other Rapido units (made at different factories, like the FP7's, F40's and B36's released recently) haven't had widestread issues like the RS18's have. There had been mention a CV fix was applied at the factory to the RS11's in light of the issues with the RS18 decoders/motors being discovered and tested, but it sounds like it didn't totally fix the problem in this case.
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Post by llxlocomotives on Jul 3, 2020 6:27:26 GMT -8
Your speed issues are due to the voltage at the motor. Your units are fairly typical for today’s models. The link I showed earlier has a chart that depicts the voltage function for speed for three Rapido models compared to the average of twenty five Kato models and a data base of 400 models.
Your discussion on pulling power is depicted here:
This activity is focused on grade & train length, but there is some useful results that can be used in your application. A lot of the data shown is from the RS-18 running I described earlier.
Others have shown & I have demonstrated that doing a clean, adjust & tune activity often will markedly improve pulling capacity, even on brand new models because it reduces the internal torque losses. That usually does not have much impact on the velocity at voltage.
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Post by amtrakfl9 on Jul 3, 2020 13:32:53 GMT -8
amtrakfl9, Well, I ran all 5 of my Rapido FL9's Thursday night. I found one error in my earlier post: the no-load DCC track voltage through our speed trap is 14.5v, not 13.5v. The voltage was measured with an RMS meter, so it's a true voltage reading (again, without a load). After a few passes to warm up the motors, my FL9's all ran 58 to 65 mph individually (no train). Some ran faster backwards or forwards, others were equal in either direction. The speed trap area has no grade. I then put 14 passenger cars behind a pair of FL9's. The cars were 6 Rapido 8600 coaches with the original trucks that don't roll that well, 5 Rapido parlor cars with very free rolling trucks, 1 Rapido diner, and two Soho brass cars (Obs and County car). There was no difference in speed with two FL9's. Next, I used the same train with just one engine. When starting, the FL9 wheels slipped pretty badly but the train started and got up to its max speed. The result was that the top speed was about 10 mph slower with one unit. I would say that I had almost maxed out the pulling power; there's no way it would have climbed any grade with that train. How are you running your FL9's? Singly with a bunch of cars? And what's your track voltage? I usually run an FL9 solo with 4 WalthersProto Amsleds, which is all they can handle without wheelslip on grades. My club hasn't been open since March unfortunately so I can't give you a definite voltage reading, but we try to keep it around 13.5 volts. We measure voltage with an RRAmpMeter V2. Your range of 58 to 65 mph minus 10 with a heavy train seems to line up more or less with what I have experienced, maybe plus or minus a few mph due to track voltage. I think that speed range is far too slow for a passenger diesel. Hopefully the modernized FL9s coming out this fall will be faster, as I plan on replacing mine with those.
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Post by mdvle on Jul 20, 2020 17:04:26 GMT -8
July 20th - Jason Shron, Jordan Smith, John Sheridan, Dan Darnell
- recollections, could be errors.
- warranty work is almost caught up from Covid shut down - accurate signals - would like to do it, unsure if there is a market given how few people do accurate signals on their layouts - RS11 second run - NKP and NP most popular so far - RS11 - NP rotary beacon - asking factory about it, if not possible sold separately - RS11 - fan height by roadname - X72 boxcar 3D design done by John Sheridan - D10 tooling delayed to have a 3D print done to check things - X72, PA/PB, and D10 should go to tooling in next 3 weeks - EP5 - test of pantograph went well (they showed a video of the test)
- hoping for SW1200 samples soon - Jordan looking for photos of the Amtrak Turboliner in Toronto - any product, in multiples of 6, can be ordered as undecorated or unnumbered - CN H6 is only 50% of the order of the CP D10 - M420 and F59PH sales slow, hoping for better numbers before August order deadline - SW1200, PA/PB sales strong - best selling US roadname - NH followed by either SP or Pennsy - new SP announcement prior to the end of the year planned - will be making an Amtrak 50th announcement
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Post by Paul Cutler III on Jul 20, 2020 18:10:12 GMT -8
mdvle, Also:
- Productivity for the designers has increased while they work from home during the pandemic. - Sales of HO scale LRC cars were 10 times the number of N scale LRC cars, which is why they don't make everything in N scale that they do in HO scale. - The tooling cost for the N scale LRC car was 80% of the cost of the HO tooling for the LRC car, but the N scale retail price is ~60% of the HO car. - Futurama is better than Star Trek.
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Post by jonklein611 on Jul 20, 2020 19:08:03 GMT -8
mdvle, Also: - Productivity for the designers has increased while they work from home during the pandemic. - Sales of HO scale LRC cars were 10 times the number of N scale LRC cars, which is why they don't make everything in N scale that they do in HO scale. - The tooling cost for the N scale LRC car was 80% of the cost of the HO tooling for the LRC car, but the N scale retail price is ~60% of the HO car. - Futurama is better than Star Trek.
Ironically, they made the Amtrak LRC cars in N only this round. I need to super size some for my HO Amtrak LRC.
I wonder if there is a plan for the N LRC locomotive?
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Post by mdvle on Jul 20, 2020 19:33:30 GMT -8
mdvle, Also: - Productivity for the designers has increased while they work from home during the pandemic. - Sales of HO scale LRC cars were 10 times the number of N scale LRC cars, which is why they don't make everything in N scale that they do in HO scale. - The tooling cost for the N scale LRC car was 80% of the cost of the HO tooling for the LRC car, but the N scale retail price is ~60% of the HO car. - Futurama is better than Star Trek.
Ironically, they made the Amtrak LRC cars in N only this round. I need to super size some for my HO Amtrak LRC.
I wonder if there is a plan for the N LRC locomotive?
Well, this is an HO forum, not N, but I would guess at best a maybe and not for a while if yes.
The N scale folks have enough trouble getting the budget for the already announced N stuff that is coming in the next 12 to 24 months.
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Post by Paul Cutler III on Jul 20, 2020 20:07:32 GMT -8
More:
- Rapido uses three different mold shops as they do not cut tooling in-house...yet. But switching to in-house tooling would require them to move the factory out of town due to environmental concerns. - They are trying out a new mold shop. - HO Comet car tooling is done and samples are expected any day.
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Post by jonklein611 on Jul 21, 2020 4:40:30 GMT -8
Well, this is an HO forum, not N, but I would guess at best a maybe and not for a while if yes.
The N scale folks have enough trouble getting the budget for the already announced N stuff that is coming in the next 12 to 24 months.
I wear both hats, so my wallet is currently on fire. Looking forward to the N Canadian, and new HO LRC cars.
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Post by edwardsutorik on Jul 21, 2020 6:22:28 GMT -8
I wonder what element of cutting tooling would generate environmental concerns.
Ed
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Post by jonklein611 on Jul 21, 2020 6:37:16 GMT -8
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