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Let's Talk...INERTIA???
 Moderated by: W C Greene Page:  First Page Previous Page  1  2  3  4  5  Next Page Last Page  
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 Posted: Sun Apr 3rd, 2016 05:54 pm
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davecttr
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Bob D wrote:
Thanks guys (and thank you "Outlaw")

I think I'll adjust the MIN a bit and see what goes.

If I adjust it, what happens at the top end?

If the voltage is set higher at the low end (let's say the engine starts moving at 15 degrees, I would think I would top out at 85% (movement of the knob) and the rest of the throttle knob movement wouldn't do anything?

Bob

According to David T if you set MIN to say 10% and MAX to say 85% the full movement of the knob will give 10-85% rather than 0-100%, I think ?

Last edited on Sun Apr 3rd, 2016 05:54 pm by davecttr



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 Posted: Sun Apr 3rd, 2016 08:27 pm
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Bob D
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Dave,

See if this makes sense, I'm probably leaving something out but this is about as easy as I can explain what I'm thinking:

I have an 11.1v battery, the RCS Tx3/Tx7k has 300 degrees of throttle knob rotation.  If I leave the settings alone I get:

0---------11.1volts
0---------300 degrees of throttle knob rotation
(so 1 degree of rotation = .037 volts)(11.1/300)

Now if I change the low end (MIN) to 10%:

1.11 (10% MIN change)------11.1volts
0---------300 degrees of throttle knob rotation
(so 1 degree of rotation = .033 volts)(11.1-1.11=9.89) (9.89/300)

Are these things that linear or have I completely fallen off the track???

I guess the only good way of showing this would be on a scope, which I don't have.

Anybody buy one of these yet:

NANO SCOPE

Bob



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 Posted: Sun Apr 3rd, 2016 10:56 pm
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davecttr
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That calculation looks OK if the pot is truly linear but apparently manufacturing tolerances will mean the voltage curve will not be a straight line but wobble about a bit. I tested this some time ago the hard way by measuring the output voltage with different throttle settings, not an accurate way of doing it.

Last edited on Sun Apr 3rd, 2016 11:00 pm by davecttr



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 Posted: Tue May 3rd, 2016 09:57 pm
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Budd
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Bob D wrote:
Budd wrote: On 'max' inertia setting, the only change was that it took a l..o..n..g time to start then acceleration was very brisk any way and shutting it of had little effect in that it wouldn't stop.

Wayne from Oz.

Wayne,  that's what I'm seeing also.

When I turn the throttle knob on my RCS Tx7k or Tx3 I have to turn it approximately 25-30 degrees to get the engine to move.  When it does it's not a jack-rabbit start, but not a slow ramping up of movement as I would like.

I only have this problem with 2 out of 8 engines, so I'm pretty sure it's not the electronics but the mechanics (weight, gearing, mass, etc) inside the engines.



BobD.


And to add to this thread, I have just fitted Rx60's to an Athearn Mikado and a shunter powered by 2 Steam Era Black beetle drives, both programmed for low off, and they run superbly from near zero throttle, so it must be all about the mechanics of a drive. All have some inertia effect even though I have removed the inertia pot from my TX22.

Wayne from Oz



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 Posted: Tue May 3rd, 2016 11:25 pm
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Bob D
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Thanks Wayne [toast][toast]

I haven't had a chance to do any testing of my own, a couple of projects got in the way and my daughter, son-in-law, and grandson came in late last month from Sicily for a few weeks.

Being I have all but 1 or 2 engines running fine and using the same gear, I'm calling it mechanical as well.

BobD.



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 Posted: Wed May 3rd, 2017 11:03 am
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Bob D
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Wow, it's been a year since I last posted to this topic.  Not sure what made me even look at the post L:
Kinda strange, it's also been 3 years since my wife passed.
Anyway, I haven't done any testing, things seem to be working fine as they are. I did notice that my 2 best slow running engines have 15vdc motors in them where the others have 12vdc from what I can tell.
I'm considering converting an AtlasO F3 from TMCC to BPRC, this will be my first diesel to get the Rx65b.
All my diesels have 2 motors (the steamers had only 1), I hope they don't draw too much current, I think there's a flywheel on both motors, but need to open it to make sure and to make sure there's enough room for the battery.  Hiding the on/off switch and the charging jack will be a challenge, I want to locate them so I don't have to lift the engine off the track.
Has anyone done any testing with the inertia settings?



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 Posted: Wed May 3rd, 2017 11:41 am
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Helmut
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I use the inertia control 'as is' on the Tx22 and only as a brake. That is, when starting the inertia knob is mostly set to the low position, but before slowing down, I turn it fully up, close the regulator and use it to control the rate of slowdown. Works fine for me.



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 Posted: Wed May 3rd, 2017 03:53 pm
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Bob D
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Helmut,

I might have to get a TX22 so I can easily change the inertia.  I have the Tx 2, 3, and 7 from Tony W. at RCS Australia, but they don't have a knob specifically for inertia.

A knob would be much easier than changing the programming.  However, the RCS Tx are doing fine for my purposes right now.

Again I would like to thank TonyW and DavidT for offering their great products.  Going on 3 years now and ZERO failures or glitches (other than those caused by "pilot error").



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 Posted: Mon Aug 14th, 2017 08:11 pm
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bobquincy
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@BobD,

I have worked with the inertia control on most of my models.  It seems a little goes a long way, I rarely turn it beyond 1/4.  I plan to play around with different pots to see if I can adjust the full travel more to my liking.

I have used the inertia setting on some receivers to limit acceleration for motors where rapid acceleration can overload the voltage step-up converter that I used.

There was a question about a NanoScope, I have a PicoScope (2204 low end) and am really happy with it and the software.

boB



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 Posted: Tue Aug 15th, 2017 07:46 am
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DavidT
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Bob, So you know what you are dealing with, Inertia in my Tx2 product has 32 steps. You can add resistors to make the pot only give you access to a smaller number of steps. Regards, David.

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