Lyn >> Schull & Skibbereen Erin(ish)
Re: Lyn >> Schull & Skibbereen Erin(ish)
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.
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.
Philip
Re: Lyn >> Schull & Skibbereen Erin(ish)
My thinking exactly. It would be difficult to construct such a convoluted shape in any other way, methinks.
Rik
Re: Lyn >> Schull & Skibbereen Erin(ish)
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
Re: Lyn >> Schull & Skibbereen Erin(ish)
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!!
Rik
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!!
Rik
Re: Lyn >> Schull & Skibbereen Erin(ish)
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
https://www.technobotsonline.com/gear-s ... lator.html
Rik
Re: Lyn >> Schull & Skibbereen Erin(ish)
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.
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.
Re: Lyn >> Schull & Skibbereen Erin(ish)
Thanks JimJimmyb wrote: βSat 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.
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
Re: Lyn >> Schull & Skibbereen Erin(ish)
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.....
PS I was looking for another emoji to say how brilliant it is, but it seems to have disappeared....
SUPBERB.....
PS I was looking for another emoji to say how brilliant it is, but it seems to have disappeared....
ROD
Life is so easy when I run my trains.
https://gardenrails.org/forum/viewtopic ... 41&t=11364
https://www.youtube.com/@fairywoodlightrailway
Life is so easy when I run my trains.
https://gardenrails.org/forum/viewtopic ... 41&t=11364
https://www.youtube.com/@fairywoodlightrailway
Re: Lyn >> Schull & Skibbereen Erin(ish)
Edit - apologies, this post adds nothing to the thread, but Philip's comment made me laugh out loud!
Phil
Sporadic Garden Railer who's inconsistencies know no bounds
My Line - https://gardenrails.org/forum/viewtopic ... 41&t=11077
Sporadic Garden Railer who's inconsistencies know no bounds
My Line - https://gardenrails.org/forum/viewtopic ... 41&t=11077
Re: Lyn >> Schull & Skibbereen Erin(ish)
I think I've cracked it!!
Only took me three months!
Rik
Only took me three months!
Rik
Re: Lyn >> Schull & Skibbereen Erin(ish)
Fantastic Rik..Well done, she doe's indeed run very smoothly now. I didn't notice any slipping at all, what a fantastic feeling you must have had when you saw her running and pulling all those wagons.
I agree also about having to redesign stuff with 3d builds, I am always doing it.....
I agree also about having to redesign stuff with 3d builds, I am always doing it.....
ROD
Life is so easy when I run my trains.
https://gardenrails.org/forum/viewtopic ... 41&t=11364
https://www.youtube.com/@fairywoodlightrailway
Life is so easy when I run my trains.
https://gardenrails.org/forum/viewtopic ... 41&t=11364
https://www.youtube.com/@fairywoodlightrailway
Re: Lyn >> Schull & Skibbereen Erin(ish)
Looks fine to me, Rik.
Very satisfying when you get to this stage.
Very satisfying when you get to this stage.
Philip
Re: Lyn >> Schull & Skibbereen Erin(ish)
Thanks chaps. She still needs to be tidied up a bit and some of the detailing installed ( eg the outside frames) but I'm pleased with how she now performs. You'll also notice the chuff synch now needs re-adjustment but she's now much more controllable at slow speeds.
Rik
Rik
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Re: Lyn >> Schull & Skibbereen Erin(ish)
An A+ for perseverance Rik. You must be very happy to see it dragging all those wagons.
And a most interesting video too.
And a most interesting video too.
Greg from downunder.
The Sandstone & Termite's website: https://members.optusnet.com.au/satr/satr.htm
The Sandstone & Termite's website: https://members.optusnet.com.au/satr/satr.htm
Re: Lyn >> Schull & Skibbereen Erin(ish)
I really enjoyed watching the video, your railway is beautiful.
It's fun for me to see Skibbereen mentioned as that is where I live.
It's fun for me to see Skibbereen mentioned as that is where I live.
Michaela in West Cork
Re: Lyn >> Schull & Skibbereen Erin(ish)
A lovely part of the world and definitely on my list of go to locations once this Covid business is over
Rik
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