To notch or not to notch

Discussion of Live Steam locomotives should be located here
User avatar
Keith S
Driver
Driver
Posts: 1624
Joined: Thu Feb 24, 2011 11:44 pm
Location: Canada

Re: To notch or not to notch

Post by Keith S » Tue Aug 21, 2018 9:24 am

It turns out I've been confusing what the word "drag" means. You're right, it's not "drag". The whole point to any device that attempts to make a toy engine act realistically isn't to resist motion, it's to resist acceleration. A friction device resists acceleration by resisting motion, and it applies a greater force parallel and opposite to the force applied by the locomotive in the direction of movement as speed increases. It will limit top speed. A flywheel device resists accelleration by absorbing a percentage of the force applied in the direction of motion by the locomotive and storing it in the form of angular momentum. It will not limit top speed. Therefore you are correct to say the Slomo does not add "drag" to the locomotive. However, during acceleration, there is more work being done to produce a given rate of increase in speed than there would be if the locomotive was not equipped with a flywheel and was simply being driven very carefully. There is greater force being applied to the crank, and therefore more wear is occurring. It may be your contention that it is not possible to control an engine carefully enough to create the same realistic accelleration as the Slomo does. I agree with you there. I believe slightly increased wear is the price you pay for the advantages of the Slomo, or the flywheel van that I use. Also, my engine is manually controlled, so I do put the regulator where I think it ought to be for the speed I want, and can't "drive" it.

God, I'm a bore. I think I've been arguing with myself because I imagined someone saying the flywheel device doesn't increase wear over time, and I have been arguing with that imaginary person. Enjoy your trains. Thanks for the discussion.

User avatar
Hydrostatic Dazza
Driver
Driver
Posts: 1167
Joined: Tue Sep 19, 2017 4:17 am
Location: Brisbane
Contact:

Re: To notch or not to notch

Post by Hydrostatic Dazza » Tue Aug 21, 2018 10:15 am

Keith S wrote: Tue Aug 21, 2018 9:24 am It turns out I've been confusing what the word "drag" means. You're right, it's not "drag". The whole point to any device that attempts to make a toy engine act realistically isn't to resist motion, it's to resist acceleration. A friction device resists acceleration by resisting motion, and it applies a greater force parallel and opposite to the force applied by the locomotive in the direction of movement as speed increases. It will limit top speed. A flywheel device resists accelleration by absorbing a percentage of the force applied in the direction of motion by the locomotive and storing it in the form of angular momentum. It will not limit top speed. Therefore you are correct to say the Slomo does not add "drag" to the locomotive. However, during acceleration, there is more work being done to produce a given rate of increase in speed than there would be if the locomotive was not equipped with a flywheel and was simply being driven very carefully. There is greater force being applied to the crank, and therefore more wear is occurring. It may be your contention that it is not possible to control an engine carefully enough to create the same realistic accelleration as the Slomo does. I agree with you there. I believe slightly increased wear is the price you pay for the advantages of the Slomo, or the flywheel van that I use. Also, my engine is manually controlled, so I do put the regulator where I think it ought to be for the speed I want, and can't "drive" it.

God, I'm a bore. I think I've been arguing with myself because I imagined someone saying the flywheel device doesn't increase wear over time, and I have been arguing with that imaginary person. Enjoy your trains. Thanks for the discussion.
YES, we are on the same page.
discussing is always a good thing.
Cheers from Dazza, The Hydrostatic Lubricator 8)
The chances of finding out what’s really going on in the universe are so remote, the only thing to do is hang the sense of it and keep yourself occupied. Douglas Adams

User avatar
tom_tom_go
Driver
Driver
Posts: 4824
Joined: Wed Feb 23, 2011 3:08 am
Location: Kent, UK
Contact:

Re: To notch or not to notch

Post by tom_tom_go » Tue Aug 21, 2018 8:02 pm

I keep reading that a SSP Slomo causes more wear to a loco than one without. Does it cause more wear than say adding an extra wagon or two to a train or driving your loco on demanding track with gradients?

Until a SSP Slomo has been fitted to a brand new loco then the same loco purchased without a Slomo and then they are run in identical conditions over a period of time (talking years) to compare 'wear' then the statement of a Slomo causes more wear is false.

Please read the following:

http://smallsteamperformance.com.au/wear-issues/

User avatar
Hydrostatic Dazza
Driver
Driver
Posts: 1167
Joined: Tue Sep 19, 2017 4:17 am
Location: Brisbane
Contact:

Re: To notch or not to notch

Post by Hydrostatic Dazza » Tue Aug 21, 2018 11:01 pm

tom_tom_go wrote: Tue Aug 21, 2018 8:02 pm I keep reading that a SSP Slomo causes more wear to a loco than one without. Does it cause more wear than say adding an extra wagon or two to a train or driving your loco on demanding track with gradients?

Until a SSP Slomo has been fitted to a brand new loco then the same loco purchased without a Slomo and then they are run in identical conditions over a period of time (talking years) to compare 'wear' then the statement of a Slomo causes more wear is false.

Please read the following:

http://smallsteamperformance.com.au/wear-issues/

Yes, I am not yet convinced a Slomo mech causes more noticeable or measurable wear if one drives the loco gently and not forcing the flywheel up to speed quickly and also when slowing so the peak forces are kept low. Just as if you were driving or controlling anything with care.
As you say, I want to see data. Measurements taken of two new locos, one with fitted Slomo and one with out. Then control as far as possible all the conditions and variables. Record all. Then after time has passed, take measurements of the parts.

"I am also weary of anecdotal reports of what occurs because there are so many unmeasured or unrecorded variables, the locos set up and condition, driving technique etc etc. The plural of anecdote does not = fact."
Cheers from Dazza, The Hydrostatic Lubricator 8)
The chances of finding out what’s really going on in the universe are so remote, the only thing to do is hang the sense of it and keep yourself occupied. Douglas Adams

User avatar
dewintondave
Trainee Driver
Trainee Driver
Posts: 697
Joined: Mon Mar 07, 2011 8:52 am
Location: New Zealand

Re: To notch or not to notch

Post by dewintondave » Wed Aug 22, 2018 8:02 am

It will cause extra wear, because it's an extra load for the loco. Anyway, if one can afford a ssp slomo, one can afford repairs :D
Best wishes,
Dave

User avatar
tom_tom_go
Driver
Driver
Posts: 4824
Joined: Wed Feb 23, 2011 3:08 am
Location: Kent, UK
Contact:

Re: To notch or not to notch

Post by tom_tom_go » Wed Aug 22, 2018 8:10 am

dewintondave wrote: Wed Aug 22, 2018 8:02 am It will cause extra wear, because it's an extra load for the loco. Anyway, if one can afford a ssp slomo, one can afford repairs :D
Running a loco with a heavy train causes extra wear as well :mrgreen:

User avatar
TonyW
Driver
Driver
Posts: 1357
Joined: Fri May 16, 2008 9:25 am
Location: North Wales
Contact:

Re: To notch or not to notch

Post by TonyW » Wed Aug 22, 2018 1:47 pm

tom_tom_go wrote: Wed Aug 22, 2018 8:10 amRunning a loco with a heavy train causes extra wear as well :mrgreen:
Which is, of course, another solution!

Want to tame your loco? Put a bigger train behind it.

Want your loco to chuff louder? Put a bigger train behind it.

:D

User avatar
Keith S
Driver
Driver
Posts: 1624
Joined: Thu Feb 24, 2011 11:44 pm
Location: Canada

Re: To notch or not to notch

Post by Keith S » Wed Aug 22, 2018 5:11 pm

The best way to avoid wear, as well as to make the most efficient use of a given quantity of butane or coal, is to leave the loco on a shelf and dust it off once in a while. This is what I do, and this style of running induces practically no wear to the running gear, uses very little butane, and the locomotive goes very slowly indeed. It's been on the shelf about a year now and the engine hasn't even moved far enough to run the slack out of the coupling chains. I have to admit, the chuff is extremely quiet however.

User avatar
IanC
Trainee Driver
Trainee Driver
Posts: 798
Joined: Mon Feb 15, 2016 9:15 am
Location: Nr. Warrington, Cheshire

Re: To notch or not to notch

Post by IanC » Wed Aug 22, 2018 8:32 pm

Keith S wrote: Wed Aug 22, 2018 5:11 pm The best way to avoid wear, as well as to make the most efficient use of a given quantity of butane or coal, is to leave the loco on a shelf and dust it off once in a while. This is what I do, and this style of running induces practically no wear to the running gear, uses very little butane, and the locomotive goes very slowly indeed. It's been on the shelf about a year now and the engine hasn't even moved far enough to run the slack out of the coupling chains. I have to admit, the chuff is extremely quiet however.
:thumbright: :lol: :lol: :lol: That's so very true. I don't run my locos enough to wear them out in my lifetime. With or without a slomo or running big trains.
Ian

User avatar
dewintondave
Trainee Driver
Trainee Driver
Posts: 697
Joined: Mon Mar 07, 2011 8:52 am
Location: New Zealand

Re: To notch or not to notch

Post by dewintondave » Wed Aug 22, 2018 9:28 pm

tom_tom_go wrote: Wed Aug 22, 2018 8:10 am Running a loco with a heavy train causes extra wear as well :mrgreen:
Running a heavy train with a slomo equipped loco would be like cruelty to engines 💪
Best wishes,
Dave

User avatar
Hydrostatic Dazza
Driver
Driver
Posts: 1167
Joined: Tue Sep 19, 2017 4:17 am
Location: Brisbane
Contact:

Re: To notch or not to notch

Post by Hydrostatic Dazza » Wed Aug 22, 2018 9:53 pm

Keith S wrote: Wed Aug 22, 2018 5:11 pm The best way to avoid wear, as well as to make the most efficient use of a given quantity of butane or coal, is to leave the loco on a shelf and dust it off once in a while. This is what I do, and this style of running induces practically no wear to the running gear, uses very little butane, and the locomotive goes very slowly indeed. It's been on the shelf about a year now and the engine hasn't even moved far enough to run the slack out of the coupling chains. I have to admit, the chuff is extremely quiet however.
Image
Cheers from Dazza, The Hydrostatic Lubricator 8)
The chances of finding out what’s really going on in the universe are so remote, the only thing to do is hang the sense of it and keep yourself occupied. Douglas Adams

User avatar
tom_tom_go
Driver
Driver
Posts: 4824
Joined: Wed Feb 23, 2011 3:08 am
Location: Kent, UK
Contact:

Re: To notch or not to notch

Post by tom_tom_go » Sun Sep 09, 2018 5:09 pm

steveh99 wrote: Sun Aug 19, 2018 4:14 pm If anyone can better this without a slomo, paste your video here. I don't have anything else to say on this subject
I thought I would post this in response although I obviously have a Slomo fitted ;)


User avatar
Keith S
Driver
Driver
Posts: 1624
Joined: Thu Feb 24, 2011 11:44 pm
Location: Canada

Re: To notch or not to notch

Post by Keith S » Wed Sep 12, 2018 1:35 am

Amazing. A real driver on a full-sized locomotive would be hard-pressed to drive that delicately. Also, I love the simulated drain cocks. The little spurt of steam from the vicinity of the cylinders is very convincing and adds a lot of visual appeal.

User avatar
dewintondave
Trainee Driver
Trainee Driver
Posts: 697
Joined: Mon Mar 07, 2011 8:52 am
Location: New Zealand

Re: To notch or not to notch

Post by dewintondave » Wed Sep 12, 2018 8:41 am

tom_tom_go wrote: Sun Sep 09, 2018 5:09 pm I thought I would post this in response although I obviously have a Slomo fitted ;)
Here's my contribution, it doesn't have a Slomo fitted, unlike Tom's... :D

Zip along to 2:42
Best wishes,
Dave

User avatar
Andrew
Moderator
Moderator
Posts: 3247
Joined: Tue Jul 03, 2012 1:33 pm
Location: Bristol, UK
Contact:

Re: To notch or not to notch

Post by Andrew » Wed Sep 12, 2018 10:29 am

Keith S wrote: Wed Sep 12, 2018 1:35 am Amazing. A real driver on a full-sized locomotive would be hard-pressed to drive that delicately.
I recall a TV programme about thirty years ago, possibly "You Bet", in which a driver at the Mid-Hants Railway attempted to drive his loco, a Bulleid Pacific, up to another (the T9, I think) so gently that he could trap an egg between the buffers of the two without cracking it. Alas, he failed, but I reckon he must have succeeded many times before or they wouldn't have attempted it on Saturday evening telly. Although I believe Bulleid's loco's were fitted with Slomos...

User avatar
Keith S
Driver
Driver
Posts: 1624
Joined: Thu Feb 24, 2011 11:44 pm
Location: Canada

Re: To notch or not to notch

Post by Keith S » Wed Sep 12, 2018 6:22 pm

Well, I DID say "hard pressed", not that it would be impossible! Of course, on a Bullied Pacific, the massive boxpok driving wheels and chain-driven valve gear probably has the same effect as a "slomo", so I don't know if you're quite correct about them not having one!

:D

User avatar
tom_tom_go
Driver
Driver
Posts: 4824
Joined: Wed Feb 23, 2011 3:08 am
Location: Kent, UK
Contact:

Re: To notch or not to notch

Post by tom_tom_go » Sun Sep 16, 2018 12:16 pm

Another Slomo example:


User avatar
dewintondave
Trainee Driver
Trainee Driver
Posts: 697
Joined: Mon Mar 07, 2011 8:52 am
Location: New Zealand

Re: To notch or not to notch

Post by dewintondave » Sun Sep 16, 2018 10:44 pm

Listen to that loud chuff, the poor NA must be struggling against the non-drag of the slomo!
Best wishes,
Dave

User avatar
tom_tom_go
Driver
Driver
Posts: 4824
Joined: Wed Feb 23, 2011 3:08 am
Location: Kent, UK
Contact:

Re: To notch or not to notch

Post by tom_tom_go » Mon Sep 17, 2018 7:39 am

dewintondave wrote: Sun Sep 16, 2018 10:44 pm Listen to that loud chuff, the poor NA must be struggling against the non-drag of the slomo!
It has a Summerlands Chuffer fitted Dave.

Listen to these NA's you can hear the difference:


User avatar
dewintondave
Trainee Driver
Trainee Driver
Posts: 697
Joined: Mon Mar 07, 2011 8:52 am
Location: New Zealand

Re: To notch or not to notch

Post by dewintondave » Mon Sep 17, 2018 8:14 am

tom_tom_go wrote: Mon Sep 17, 2018 7:39 am It has a Summerlands Chuffer fitted Dave.

Listen to these NA's you can hear the difference:
That was a marvellous sight Tom

They really do sound different
Best wishes,
Dave

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest