Lyn >> Schull & Skibbereen Erin(ish)

What is your latest project?
User avatar
ge_rik
Administrator
Administrator
Posts: 6497
Joined: Sun Oct 25, 2009 10:20 pm
Location: Cheshire
Contact:

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by ge_rik » Thu Feb 18, 2021 2:33 pm

GTB wrote: Thu Feb 18, 2021 10:14 am More poor design than poor plastic, although recycled plastic won't help. I've repaired a few electronic device cases over the years with the same problem of the screw pillars cracking, but I've also got a couple designed so that they'll never crack.

I use pieces of brass tube as a collar pressed on over the split post as a repair. The tube needs to be a tight enough push fit to close the crack in the plastic and it won't work if any chunks of plastic have broken away from the post.

The repair will last, but only if you are careful about tightening up the screws, as the self tappers used can easily strip out the thread in plastic if over tightened.
Past that stage, unfortunately. Most of the pieces of the various pillars have parted company and either disappeared or are rattling around inside the clamshell.
GTB wrote: Thu Feb 18, 2021 10:14 am The loco body has come up nicely, but I agree, it needs a dummy frame behind the cylinders and from there to the front headstock. There's far too much daylight under the front at present.
The dummy frame is now done and, as on the Lyn, serves a triple purpose of filling the space, retaining the cylinder moulding and securing the body to the motor block..

I'll post a few photos later.

Rik
------------------------
Peckforton Light Railway - Blog Facebook Youtube

User avatar
ge_rik
Administrator
Administrator
Posts: 6497
Joined: Sun Oct 25, 2009 10:20 pm
Location: Cheshire
Contact:

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by ge_rik » Mon Feb 22, 2021 12:56 pm

On the home straight ........
Image


Image


Image

(Images hosted on my blog - https://riksrailway.blogspot.com/2021/0 ... rt-88.html )

There's still a bit more to be done - a bit more pipework, nameplates, numberplates, makers' plates and some gauges, pipes and brake standard in the cab. She seems to run quite well but I've not had a chance to do a full test run as yet.

3 x 18650 li-ion cells, Deltang Rx65c receiver/controller and MyLocoSound Universal steam soundcard.

Rik
------------------------
Peckforton Light Railway - Blog Facebook Youtube

User avatar
Peter Butler
Driver
Driver
Posts: 5219
Joined: Sun Sep 09, 2012 10:33 pm
Location: West Wales

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by Peter Butler » Mon Feb 22, 2021 1:54 pm

That's looking really good Rik. You have managed to get a smooth paint surface too, very well done.
The best things in life are free.... so why am I doing this?

User avatar
philipy
Moderator
Moderator
Posts: 5033
Joined: Sun Jan 30, 2011 3:00 pm
Location: South Northants

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by philipy » Mon Feb 22, 2021 5:12 pm

Yes, I agree with Peter, a very nice job.
Philip

User avatar
ge_rik
Administrator
Administrator
Posts: 6497
Joined: Sun Oct 25, 2009 10:20 pm
Location: Cheshire
Contact:

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by ge_rik » Mon Feb 22, 2021 6:12 pm

Thanks chaps
I've now blogged the build here in case anyone wants to see wot I dun
https://riksrailway.blogspot.com/2021/0 ... -into.html

Rik
------------------------
Peckforton Light Railway - Blog Facebook Youtube

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

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by Andrew » Wed Feb 24, 2021 2:53 pm

That's a lovely-looking loco Rik - it will look equally at home at the head of a posh passenger rake or roughing it with a goods...

User avatar
Sylvian Tennant
Fireman
Fireman
Posts: 327
Joined: Wed Aug 10, 2011 4:48 pm
Location: Teesside

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by Sylvian Tennant » Sun Mar 07, 2021 1:31 pm

Lovely work Rik. This CAD/3D print malarkey is certainly becoming very tempting.

User avatar
-steves-
Administrator
Administrator
Posts: 2412
Joined: Thu Jul 28, 2011 1:50 pm
Location: Cambridge & Peterborough

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by -steves- » Sun Mar 07, 2021 6:17 pm

Agree with what everyone else has said, great design, great build and excellent finish, very well done :thumbup:
The buck stops here .......

Ditton Meadow Light Railway (DMLR)
Member of Peterborough and District Association
http://peterborough.16mm.org.uk/

User avatar
ge_rik
Administrator
Administrator
Posts: 6497
Joined: Sun Oct 25, 2009 10:20 pm
Location: Cheshire
Contact:

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by ge_rik » Mon Mar 15, 2021 3:53 pm

Update on progress

It's taken me a while - three or four re-designs plus a few duff prints - but at last I now have a purpose-made clamshell housing for the motor block to accommodate the larger motor which was installed by a previous owner.

Image


I moved the axles out by a couple of mm to ensure the worm wheels were more central on the worms and also to make sure they couldn't rub against the motor casing as previously happened. It means I'll have to extend the connecting rods - but that's a small price to pay....

Rik
------------------------
Peckforton Light Railway - Blog Facebook Youtube

User avatar
Peter Butler
Driver
Driver
Posts: 5219
Joined: Sun Sep 09, 2012 10:33 pm
Location: West Wales

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by Peter Butler » Mon Mar 15, 2021 4:10 pm

Now that's what 3D printing is for!
The best things in life are free.... so why am I doing this?

User avatar
philipy
Moderator
Moderator
Posts: 5033
Joined: Sun Jan 30, 2011 3:00 pm
Location: South Northants

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by philipy » Mon Mar 15, 2021 4:30 pm

Very nice job Rik.

I'm going to have to do something similar but starting from scratch, for my Wickham trolley. I just hope I can do as well. :roll:
Philip

User avatar
ge_rik
Administrator
Administrator
Posts: 6497
Joined: Sun Oct 25, 2009 10:20 pm
Location: Cheshire
Contact:

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by ge_rik » Mon Mar 15, 2021 5:54 pm

Peter Butler wrote: Mon Mar 15, 2021 4:10 pm Now that's what 3D printing is for!
My thinking exactly. It would be difficult to construct such a convoluted shape in any other way, methinks.

Rik
------------------------
Peckforton Light Railway - Blog Facebook Youtube

User avatar
ge_rik
Administrator
Administrator
Posts: 6497
Joined: Sun Oct 25, 2009 10:20 pm
Location: Cheshire
Contact:

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by ge_rik » Mon Mar 15, 2021 6:02 pm

philipy wrote: Mon Mar 15, 2021 4:30 pm I'm going to have to do something similar but starting from scratch, for my Wickham trolley. I just hope I can do as well. :roll:
At least I had the original on which to base it. Starting from scratch would have made it twice (if not more) as difficult.
Something I found useful (eventually), was to draw the motor, worms and bearings as a unit and use it to check how well it fitted. With TinkerCAD, I could actually turn it into a "hole' which I then used to carve a motor shaped compartment inside the closed block. It means the real motor is a perfect fit - uncannily so ...... ;)

Rik
------------------------
Peckforton Light Railway - Blog Facebook Youtube

User avatar
ge_rik
Administrator
Administrator
Posts: 6497
Joined: Sun Oct 25, 2009 10:20 pm
Location: Cheshire
Contact:

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by ge_rik » Fri Mar 19, 2021 7:39 am

And so the saga continues ...... :(

After reassembling the loco, I gave her a test run. Still very disappointing in terms of pulling power. Even with a standard load of eight goods wagons the loco really struggled up my 1:40 gradients which my other locos gallop up. It also slowed appreciably on curves; the curve on the gradient brought it to a snail's pace on full power. I discovered the gauge on the drivers was slightly wide, but pushing the wheels tighter on to the gears to bring them to gauge made minimal difference. I stripped the motor block down to see if my clamshell was rubbing on anything. Nothing evident but I filed possible pinch points just in case. I reassembled and found there was very little improvement.

In desperation, I assembled a duplicate Lyn motor block which JimmyB has kindly sent me - which looks almost new.

Another test run and exactly the same outcome! Too little power to cope with a standard train!!

I can only assume that, for whatever reason, the large worms seriously impede the motor's ability to transmit power.

My next resort is to see if I can replace the worms with smaller diameter versions. I've ordered a gear puller and have found out how to calculate the mod value of the worm wheels. I just hope I can find a couple of replacements somewhere......

I will not be defeated!! :eek:😒

Rik
------------------------
Peckforton Light Railway - Blog Facebook Youtube

User avatar
ge_rik
Administrator
Administrator
Posts: 6497
Joined: Sun Oct 25, 2009 10:20 pm
Location: Cheshire
Contact:

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by ge_rik » Fri Mar 19, 2021 7:59 am

According to this online calculator, it looks like it's a 0.5 mod gear on a 2.5mm shaft which is reassuring that it's not something obscure.

https://www.technobotsonline.com/gear-s ... lator.html

Rik
------------------------
Peckforton Light Railway - Blog Facebook Youtube

User avatar
Jimmyb
Fireman
Fireman
Posts: 492
Joined: Sat Nov 23, 2019 10:43 pm
Location: Weston-super-Mare

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by Jimmyb » Sat Mar 20, 2021 8:41 am

Rik, I believe that the smaller worm is the solution, but I do not believe anybody has mentioned what the issue (apologies if you have and I have missed it), I think this is all to with "moments around a point".

The centre of the motor spindle is the fulcrum, and the motor provides the power which is a constant (assuming constant voltage input) the the further you move from the fulcrum, less load is required to equal the power output, ergo the larger the worm the less power drive you have.

User avatar
ge_rik
Administrator
Administrator
Posts: 6497
Joined: Sun Oct 25, 2009 10:20 pm
Location: Cheshire
Contact:

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by ge_rik » Sat Mar 20, 2021 8:54 am

Jimmyb wrote: Sat Mar 20, 2021 8:41 am Rik, I believe that the smaller worm is the solution, but I do not believe anybody has mentioned what the issue (apologies if you have and I have missed it), I think this is all to with "moments around a point".

The centre of the motor spindle is the fulcrum, and the motor provides the power which is a constant (assuming constant voltage input) the the further you move from the fulcrum, less load is required to equal the power output, ergo the larger the worm the less power drive you have.
Thanks Jim
That's exactly my thinking though as a former primary school teacher my explanations are far less eloquent. I was out on a walk with a mate (a former physics teacher) yesterday and I found the easiest way to explain it was to use my walking pole like a propeller. Much more effort was required to rotate it when my other hand was stopping it further away from the handle and much less effort when the resistance was closer to the handle.

My mate agreed with my practical demonstration and then explained it all with moments.....

Rik
------------------------
Peckforton Light Railway - Blog Facebook Youtube

User avatar
philipy
Moderator
Moderator
Posts: 5033
Joined: Sun Jan 30, 2011 3:00 pm
Location: South Northants

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by philipy » Sat Mar 20, 2021 1:44 pm

ge_rik wrote: Sat Mar 20, 2021 8:54 am
then explained it all with moments.....
Blond ones? :lol:
Philip

User avatar
ge_rik
Administrator
Administrator
Posts: 6497
Joined: Sun Oct 25, 2009 10:20 pm
Location: Cheshire
Contact:

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by ge_rik » Sat Mar 20, 2021 6:37 pm

philipy wrote: Sat Mar 20, 2021 1:44 pm
ge_rik wrote: Sat Mar 20, 2021 8:54 am
then explained it all with moments.....
Blond ones? :lol:
Melting ....

Rik
------------------------
Peckforton Light Railway - Blog Facebook Youtube

User avatar
FWLR
Driver
Driver
Posts: 4262
Joined: Sat Aug 05, 2017 9:45 am
Location: Preston, Lancashire, UK

Re: Lyn >> Schull & Skibbereen Erin(ish)

Post by FWLR » Fri Jun 04, 2021 11:50 am

That is a blooming brilliant build Rik. You have mastered the art of this 3d printing stuff. Yes it is easy enough and the more you work on it, the easier it gets I have found, but I am still a marathon away from doing anything as brilliant as yours.


SUPBERB..... :goodpost


PS I was looking for another emoji to say how brilliant it is, but it seems to have disappeared....

Post Reply

Who is online

Users browsing this forum: No registered users and 3 guests