Author Topic: Rapido Dash 8-40CM  (Read 7669 times)

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BCR 570

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Re: Rapido Dash 8-40CM
« Reply #30 on: September 13, 2020, 09:52:45 PM »
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Yes, horn was F2.  All my engines have non-latching horns on F2.  The Rapido also had a grade crossing sequence on another function which was non-latching.

Tim
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peteski

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Re: Rapido Dash 8-40CM
« Reply #31 on: September 13, 2020, 11:18:52 PM »
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Yes, horn was F2.  All my engines have non-latching horns on F2.  The Rapido also had a grade crossing sequence on another function which was non-latching.

Tim

I guess I don't understand.  What DCC system allows you to configure functions other than F2 to be non-latching?

Or maybe what you perceive as non-latching function is actually latching, but the way the decoder responds simulates a non-latchign function?
For example, the grade-crossing horn sequence is activated by a latching function on the throttle. So you press that button on the throttle and it sends "function on" to the decoder, and that function remains on.  This change of state triggers the horn sequence, but the decoder ends playing it, even though that function remains "on".  Then later you press that function key again. That actually turns off that (latched) function, but the decoder sees a change of state for that function (from "on" to "off"), and that triggers the horn sequence to play.  So even with a latched function, the decoder will respond to the change of state of that function.
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Wutter

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Re: Rapido Dash 8-40CM
« Reply #32 on: September 14, 2020, 01:32:34 AM »
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I guess I don't understand.  What DCC system allows you to configure functions other than F2 to be non-latching?


You can program any function to be non-latching on Lenz
Alvin
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kscessandriver

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Re: Rapido Dash 8-40CM
« Reply #33 on: September 15, 2020, 10:37:06 PM »
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I got mine today, and dropped a LokPilot V5 into it. I'm very impressed with how it runs, and it can pull very very well. Extremely happy with the locomotive, even though I don't model Canada at all.

craigolio1

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Re: Rapido Dash 8-40CM
« Reply #34 on: September 19, 2020, 04:39:21 AM »
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Doesn't some cottage industry make those trucks, 3D printed and with all axles powered, using existing gears?


Briggs Models made a 8-40CM kit. I have three. They use a early/snoot Kato SD40-2 chassis. His kit included a new cast gearbox and side frames into which the Kato gears and axels are supposed to fit but it was not in anyway ready to be assembled, requires a huge amount of modification, was brittle, and didn’t roll freely.

He then produced a replacement gear box which was produced out of slippery plastic made on a 3D printer it was crude as well. I never got them to work and I spent HOURS at it. I actually wound up sending them back to Jeff to have him get them working and they have yet to come back.

I bought a Rapido model and worst case my three Briggs locos can be dummies I guess. I wonder if Rapido trucks could be made to fit the Kato SD40-2 chassis. Perhaps if I could get spare parts from Rapido....

Craig.

peteski

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Re: Rapido Dash 8-40CM
« Reply #35 on: September 19, 2020, 12:50:55 PM »
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Briggs Models made a 8-40CM kit. I have three. They use a early/snoot Kato SD40-2 chassis. His kit included a new cast gearbox and side frames into which the Kato gears and axels are supposed to fit but it was not in anyway ready to be assembled, requires a huge amount of modification, was brittle, and didn’t roll freely.

He then produced a replacement gear box which was produced out of slippery plastic made on a 3D printer it was crude as well. I never got them to work and I spent HOURS at it. I actually wound up sending them back to Jeff to have him get them working and they have yet to come back.

I bought a Rapido model and worst case my three Briggs locos can be dummies I guess. I wonder if Rapido trucks could be made to fit the Kato SD40-2 chassis. Perhaps if I could get spare parts from Rapido....

Craig.

Thanks for that info.  I did remember correctly.  My point was that it was possible to manufacture a short wheelbase 3-axle truck, using existing production gearing.  If that is the case then if the gearbox was injection-molded using slippery plastic.  All the axles could have been made powered. 
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craigolio1

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Re: Rapido Dash 8-40CM
« Reply #36 on: September 19, 2020, 12:54:00 PM »
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Thanks for that info.  I did remember correctly.  My point was that it was possible to manufacture a short wheelbase 3-axle truck, using existing production gearing.  If that is the case then if the gearbox was injection-molded using slippery plastic.  All the axles could have been made powered.

I haven’t inspected mine too closely, but could the middle one have a little more lateral slop in it to allow it to accommodate tighter radius turns? My A1A GMD1 has an idler in the middle too. That’s prototypical for the loco but from a modelling perspective it may allow tighter curves as well.

Craig. 

CNR5529

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Re: Rapido Dash 8-40CM
« Reply #37 on: September 19, 2020, 02:48:24 PM »
+1
That’s prototypical for the loco but from a modelling perspective it may allow tighter curves as well.

The real advantage of the floating idlers on the GMD1 models is an increase in tractive effort due to less wheels spreading the weight of the locomotive. Yes there are less powered wheels, but the wheels that are powered benefit from an increased axle load as the center axles take no load. Means longer grain trains!

That said the real GMD1 idlers were to reduce the axle load on light rails, so they lost potential tractive effort...
Because why not...

RSWController

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Re: Rapido Dash 8-40CM
« Reply #38 on: September 20, 2020, 12:25:48 PM »
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Got my units the other day. I think they look great. Haven’t had time to weather them but here are two crossing the Oliver Bridge into Minnesota.
« Last Edit: September 20, 2020, 12:28:55 PM by RSWController »

basementcalling

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Re: Rapido Dash 8-40CM
« Reply #39 on: September 20, 2020, 01:27:41 PM »
+1
Flaws or not, they are sold out almost everywhere that listed them. Seems Rapido has a solid hit on their hands.
Peter Pfotenhauer

spookshow

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Re: Rapido Dash 8-40CM
« Reply #40 on: September 26, 2020, 08:30:32 AM »
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Finally got around to finishing my review, so I don't need mine anymore. If you're looking for a CN #2400 (CN stripes scheme) w/ DCC-Sound, it's all yours for $200 (shipping included).

-Mark

sd75i

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Re: Rapido Dash 8-40CM
« Reply #41 on: November 04, 2020, 02:15:15 AM »
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  A hobby shop in Illinois has some in for $109.99 if anybody is still looking for any! 

cv_acr

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Re: Rapido Dash 8-40CM
« Reply #42 on: November 10, 2020, 12:22:15 PM »
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My point was that it was possible to manufacture a short wheelbase 3-axle truck, using existing production gearing.  If that is the case then if the gearbox was injection-molded using slippery plastic.  All the axles could have been made powered.


Now, I'm not a mechanical gear designer so I can't speak to the difficulties in designing the gears on this particular truck, but I will point out it's not just short wheelbase, but a funky axle spacing. The middle axle is closer to the front (outboard) axle than the rear (inboard) one, due to the space required (on the prototype) for the traction motors on the short truck. This could cause issues with the design.
« Last Edit: November 10, 2020, 12:23:52 PM by cv_acr »

peteski

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Re: Rapido Dash 8-40CM
« Reply #43 on: November 10, 2020, 06:11:12 PM »
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Now, I'm not a mechanical gear designer so I can't speak to the difficulties in designing the gears on this particular truck, but I will point out it's not just short wheelbase, but a funky axle spacing. The middle axle is closer to the front (outboard) axle than the rear (inboard) one, due to the space required (on the prototype) for the traction motors on the short truck. This could cause issues with the design.

I don't think that is a problem - just either vertically re-position the idler gear or use different size idler.  With idler gears the number of teeth is not relevant.  What I'm saying is that it should not be impossible to make that type of truck with 3-driven axles.
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Mark5

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Re: Rapido Dash 8-40CM
« Reply #44 on: November 10, 2020, 06:41:10 PM »
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Maybe they concluded that traction was improved over various track conditions by having the center axles non-load bearing (as previously pointed out by CNR5529).

I have no evidence to back this up.  :D