Garden Railway Forum

Thanks guys - yes its coming along nicely

LNR wrote: ↑Sun Feb 18, 2018 9:56 pm The driver looks very intent, listening for any strange sounds from his new loco.
Grant.

Grant -LOL - I think he's wondering why it is rocking back and forward like a rocking horse - he's hanging on for dear life!

Malcolm the driver (all my drivers share the same initial as the loco - which will be 'Meteor' (hoping it doesn't crash off the track and hit the ground at great speed!) is at the front of the queue to help get the weighting right on the loco next weekend to see if we can smooth things out a bit!

A great thread to follow and gives alot of food for thought,
and just goes to show how a little thought and skill can produce a
lovely little loco.

Cheers Peter

More test runs today with more weight - getting adhesion right but still rocking along - need to be more strategic with the weight additions - will keep you posted

Ok -been adding weight but my (well the locos) taller body seems to be causing some issues -

Tests this weekend

With body:-



Without:-



There are some weights (tyre weights) adhered under the chassis and inside the body - my view is that i need one or two on the far side the counter balance the driver and then a lot more at the front (like a house brick in weight!) as the nose tends to be rising - when it runs chassis only, its not as bad but the bigger body seems to exaggerate things.

Does anyone have any tips about how to best go about balancing locos - I have seen something recently but can't think where? (my age catching up with me)

markoteal wrote: ↑Tue Mar 13, 2018 11:50 am Does anyone have any tips about how to best go about balancing locos - I have seen something recently but can't think where? (my age catching up with me)

Hi. I bought a roll of lead flashing a few years ago and use that to weight all my locos. I cut pieces off the roll as needed and shove tailor made pieces into every available nook and cranny.

Regarding balancing the weights - a couple of ways I do it. I put one set of drivers on a set of kitchen scales and the other set of drivers on a pile of books to bring them up to the same height. Note down the weight shown on the scales for those drivers and then reverse the loco so the other set of drivers is on the scales and note down that weight. The idea is to get the weights to be more or less equal.

The other way to do it is to balance the loco on a pencil (or fat felt tip depending on the clearances) midway between the drivers. The idea is to adjust the weights until it just about balances.

I don't have any rule of thumb regarding the overall weight of my locos - it just depends on how much lead I can cram in.

Rik
PS - Just weighed a selection of my locos and they vary from 1.75 - 2.5kg (apart from the Simplex which weighs in at 0.7kg)

Actually, looking at the videos, I'm not sure that weight is the issue. The chassis itself does seem to roll about a lot as if one or more of the wheels is out of alignment. Is the quartering out at all?

Or maybe the back to backs are too narrow - it looks like the wheels are falling down between the rails from time to time. It was interesting that the rolling seemed to iron out when she wnet through the pointwork.

Rik

Cheers Rik - lots of good ideas there - I'll have to get busy this weekend - good news is that SWMBO is away this weekend so her digital kitchen scales may develop a new specialism (loco weigh-bridge)

ge_rik wrote: ↑Tue Mar 13, 2018 12:34 pm Actually, looking at the videos, I'm not sure that weight is the issue. The chassis itself does seem to roll about a lot as if one or more of the wheels is out of alignment. Is the quartering out at all?

Or maybe the back to backs are too narrow - it looks like the wheels are falling down between the rails from time to time. It was interesting that the rolling seemed to iron out when she wnet through the pointwork.

Rik

Yes - I did notice it evened out at certain points - I'll check those back to backs, not checked those - the quartering looks ok as I had the rods off to paint them and checked they were lined up when I put them back on but I will check again

Mark, I must say that, as Rik's first thought, my immediate thought was Quartering.
It's difficult to tell at the speed it goes though! Any chance of slowing it down and posting another vid?
Another thought would be that one(or more) wheels is not square on the axle.

Cheers for the feedback Phillip - yes, it does rattle along and thats just on one AAA battery - the other in the battery box is a dud one to make the circuit. I think the fast speed doesn't help - I may have to loan a deltang to this loco from one of the diesels till I sort this issue out or wire in one of my 'one way' esc's to slow things down.

What i may do is do a slow mo version of some of the footage I have and zoom in a bit more

I'll add checking the wheels being square on the axis to the investigation list - thanks for flagging that

I quite like the rocking around. It could be a circus train?

Reminds me of loco from Dumbo:

Sorry Mark, I'm still laughing at your driver in the second video, showing great balancing skills.
I would venture to say that the problem is not weight, but that you have one or more wheels out of true. Could be worth a check. Not quartering but the circumference of the wheel not true on the axle.
Grant.
PS apologies, I seem to be having forum problems again, with pages not appearing.

Well thanks again for all the advice - managed a quick fettle last night and found a few things on your lists - on closer inspection by taking the chassis right out and into bits, one of the wheels is quite loose on the axle and so wobbles and when it does that the quartering goes out - this also means the gap between the wheels varies

After a bit of CHLR key hole precision engineering (read I pushed it all back together tight and added a spot of glue to the wheel/axle point), I put number 5 back on the track and ........



Its not perfect but its so much better - now more of a slight side to side motion which is probably down to the motion and things not being 100% spot on quartering wise - more fettling at the weekend but at least we are heading in the right direction.

I'll also see if I cab find a slightly less powerful AAA battery to lower the speed for now!

Thanks again - power to the forum

markoteal wrote: ↑Wed Mar 14, 2018 1:47 pm
I'll also see if I cab find a slightly less powerful AAA battery to lower the speed for now!

Fit a suitably rated diode in series with the battery, between the battery and the reversing switch. A silcon diode will drop a constant voltage (usually 0.6-0.7V) which isn't affected by the current drawn and it won't generate much heat.

Fitting a switch to switch the diode in/out would also give you a simple hi/lo speed control.

A resistor can do the job, but the voltage drop varies with the current drawn and a resistor will generate heat, which isn't desirable in a mostly plastic mechanism.

Regards,
Graeme

Certainly looks a lot better now, Mark.
I still have the feeling that the problem is more a question of something still not quite square and true, than quartering.

Power to the form, what a great quote!

A great improvement - and a little bit of wobble adds to the charm of the loco.
I agree with the others - it's less likely to be a quartering problem - that would tend to give you uneven speed (a jerky forward motion) with each revolution of the wheels, I think it's more likely to be wheel wobble on the axle. You might be able to see it if you run her upside down

Rik

Cheers guys - you were right - deffo the rear axle where the sideways wobble is coming from after an upside down run - another fettle required at the weekend

And Graeme, I'll have a look at that diode approach - a simple approach for my simple little loco

Ta


Mark

After another few tweaks (and basically taking all the chassis apart including pulling 3 out of the 4 wheels off and reattaching - we are more of less there - actually works better in reverses that forward - slight 'throw' as one of the rods comes over the top going forwardbut now have it pulling something.



This video is based on 3V which is ok for speed buts struggles to pull anything else - so last night attached a 4 cell holder in there - 6V will probably be too much but will probably pop a blank in one of the holder and try 4.5V - we are getting there - more video to come over Easter

Looks much better Mark. I think that slight hesitation now is possibly quartering this time, especially since you say there is a tight spot.