millman
Part of the e-furniture
Posts: 297
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Juliet
Apr 22, 2020 16:08:19 GMT
Post by millman on Apr 22, 2020 16:08:19 GMT
Same for me, page unavailable.
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smallbrother
Elder Statesman
Errors aplenty, progress slow, but progress nonetheless!
Posts: 2,269
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Juliet
Apr 22, 2020 16:12:51 GMT
Post by smallbrother on Apr 22, 2020 16:12:51 GMT
Argh, maybe only works for facebook users?
Pete.
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Juliet
Apr 22, 2020 18:47:17 GMT
Post by builder01 on Apr 22, 2020 18:47:17 GMT
I am a Facebook user, link is broken for me too.
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smallbrother
Elder Statesman
Errors aplenty, progress slow, but progress nonetheless!
Posts: 2,269
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Juliet
Apr 22, 2020 18:56:59 GMT
Post by smallbrother on Apr 22, 2020 18:56:59 GMT
OK will try and see why Imgur failed me.
Pete.
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Juliet
Apr 22, 2020 21:53:55 GMT
Post by delaplume on Apr 22, 2020 21:53:55 GMT
Link goes to "This page isn't available" for me. Wilf Same here... Alan
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stevep
Elder Statesman
Posts: 1,070
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Juliet
Apr 23, 2020 11:58:27 GMT
Post by stevep on Apr 23, 2020 11:58:27 GMT
And me.
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Juliet
Apr 23, 2020 14:04:11 GMT
Post by delaplume on Apr 23, 2020 14:04:11 GMT
Hi Pete and SteveP Give these guys a go.....works for me ok}----------- imgbb.com/ ------------- and you get lovely photos like this !! }------- or this}----
at the prompt you'll need to select}---- BBCode full linked and whenplacing onto your forum thread the photo code should start and end like this}--- ( url ..................... url) It's quick and easy to use once you get the hang of it............ Alan
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smallbrother
Elder Statesman
Errors aplenty, progress slow, but progress nonetheless!
Posts: 2,269
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Juliet
Apr 23, 2020 17:30:20 GMT
Post by smallbrother on Apr 23, 2020 17:30:20 GMT
Hi Pete and SteveP Give these guys a go.....works for me ok}----------- imgbb.com/ ------------- and you get lovely photos like this !! }------- or this}----
at the prompt you'll need to select}---- BBCode full linked and whenplacing onto your forum thread the photo code should start and end like this}--- ( url ..................... url) It's quick and easy to use once you get the hang of it............ Alan So, At top of thread select "Insert Image" symbol? I can see the BBCode full link option which gives the format you describe. What do you do next?
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smallbrother
Elder Statesman
Errors aplenty, progress slow, but progress nonetheless!
Posts: 2,269
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Post by smallbrother on Apr 23, 2020 21:30:59 GMT
Anyway back to progress. Having 1/4red the wheels and put the axles etc back into the frames I tried a coupling rod in place. I'm afraid my cumulative errors appear to have caught up with me and some serious fettling will be needed to get this lot to turn over. I have a plan, whether I have the inclination is another matter.
The journey has been well worthwhile. if I started again I am sure I would be way better at every stage. Do I now try and kick off Mona or go back and get this right? Probably a bit of both, not much else calling as things stand with the lockdown.
Pete.
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Juliet
Apr 24, 2020 14:20:00 GMT
Post by delaplume on Apr 24, 2020 14:20:00 GMT
A PM on it's way to you---
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Juliet
Apr 25, 2020 8:35:49 GMT
Post by Roger on Apr 25, 2020 8:35:49 GMT
Hi Pete, I think the way forward is to measure exactly what you've got to the best of your ability so you know what changes need to be made. When my chassis had a tight spot, it took a whole day's worth of measuring and checking before I could see for sure where the biggest error was. That turned out to be the radius of one of the crank pins was different to the rest of them. If you don't know where the errors are, you'll just keep adding clearance unnecessarily rather than tackling where the problem really lies.
So I'd suggest you start by measuring the crank pin throws. You can do that by setting up each axle in turn between centres on the lathe, using a dial gauge to just kiss the crank pin as it goes past. Write a number on each wheel for reference. You can take the axle out without disturbing the clock, and try the other end. Repeat for all the wheels, noting the figures as you go.
If you do this sort of thing for all of the dimensions, you ought to be able to build a picture of what you've got. It's not quick, but it will probably save a lot of heartache.
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smallbrother
Elder Statesman
Errors aplenty, progress slow, but progress nonetheless!
Posts: 2,269
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Juliet
Apr 25, 2020 12:10:56 GMT
Post by smallbrother on Apr 25, 2020 12:10:56 GMT
Hi Pete, I think the way forward is to measure exactly what you've got to the best of your ability so you know what changes need to be made. When my chassis had a tight spot, it took a whole day's worth of measuring and checking before I could see for sure where the biggest error was. That turned out to be the radius of one of the crank pins was different to the rest of them. If you don't know where the errors are, you'll just keep adding clearance unnecessarily rather than tackling where the problem really lies. So I'd suggest you start by measuring the crank pin throws. You can do that by setting up each axle in turn between centres on the lathe, using a dial gauge to just kiss the crank pin as it goes past. Write a number on each wheel for reference. You can take the axle out without disturbing the clock, and try the other end. Repeat for all the wheels, noting the figures as you go. If you do this sort of thing for all of the dimensions, you ought to be able to build a picture of what you've got. It's not quick, but it will probably save a lot of heartache. Thanks Roger. I have been checking axle spacings and inserted some shims to adjust the axle-boxes. Was a bit stuck as to what to do next. Will try your procedure next. Pete.
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Juliet
Apr 25, 2020 12:51:23 GMT
Post by Roger on Apr 25, 2020 12:51:23 GMT
Hi Pete, I wouldn't have thought there should be enough clearance to shim the axleboxes, they ought to be a pretty close fit really.
Another thing to do is to just fit the rod on one side only. It will only go smoothly over each centre is the crank radii are the same and the connecting rod centres are the same as the axle centres. If you've done the first test and you know the radii are the same, you can determine whether the centre distances are the same.
Another thing to note is that you have to check at both centres, not just one. If it feels different over each end, it's a sure sign that the crank radii are different. To see why this is so, draw out a perfect arrangement of two cranks complete with connecting rods. Then change the radius of one of the cranks by a large amount and see what happens at each centre.
Once you've figured out if there's an error on any of these things, you can fix them on each side before attempting to put both sides on at the same time. If they both go over centre nicely on each side, but you can't get the rod on both sides without it binding up, then it's probably going to be a problem with the quartering being different between the axles.
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smallbrother
Elder Statesman
Errors aplenty, progress slow, but progress nonetheless!
Posts: 2,269
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Post by smallbrother on Apr 30, 2020 20:18:39 GMT
Testing Pete
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smallbrother
Elder Statesman
Errors aplenty, progress slow, but progress nonetheless!
Posts: 2,269
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Post by smallbrother on Apr 30, 2020 21:54:22 GMT
Not a great photo but as you can see I have been playing about with dummy coupling rods.
I have taken measurements, tried a shim here and there, tried filing the holes, and finally I concluded the holes needed to be 10 thou closer together than on the drawing.
Worked a treat and it rolls freely now.
Pete.
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Juliet
May 1, 2020 0:11:15 GMT
Post by builder01 on May 1, 2020 0:11:15 GMT
Hey Pete, photo posted just fine! Thank you. Which holes need to be closer, the holes in the rod?
A method I used to set the distance, was to measure the distance between the axles. This should be the same distance between the holes on the rod. Does not matter what the drawing shows, the holes in rod must match the axle centers.
I measured over the axles with them pushed together and another measurement over the axles with them pushed apart. You may have to get someone to manipulate the axles while you manipulate your caliper. The average of these two measurements is the center distance between the axles. (minus the diameter of one axle!) This is also the number for the distance between the holes in the rod. I assume you have a mill to accurately position the holes. Drill and ream one hole, turn the hand wheel the distance you have for the axle centers and drill and ream the other hole.
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smallbrother
Elder Statesman
Errors aplenty, progress slow, but progress nonetheless!
Posts: 2,269
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Post by smallbrother on May 1, 2020 7:38:09 GMT
Hey Pete, photo posted just fine! Thank you. Which holes need to be closer, the holes in the rod? A method I used to set the distance, was to measure the distance between the axles. This should be the same distance between the holes on the rod. Does not matter what the drawing shows, the holes in rod must match the axle centers. I measured over the axles with them pushed together and another measurement over the axles with them pushed apart. You may have to get someone to manipulate the axles while you manipulate your caliper. The average of these two measurements is the center distance between the axles. (minus the diameter of one axle!) This is also the number for the distance between the holes in the rod. I assume you have a mill to accurately position the holes. Drill and ream one hole, turn the hand wheel the distance you have for the axle centers and drill and ream the other hole. Yes that is pretty much what I did. The axle-boxes were my first experience of using the milling machine so accuracy was not fantastic. I think the laser cut frames have probably saved my bacon. Things are not going to be anywhere near the standards of other people's builds but if it works, it works. I am quite pleased. Pete.
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uuu
Elder Statesman
your message here...
Posts: 2,812
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Post by uuu on May 1, 2020 7:57:53 GMT
Having seen many locos coming to the Pumphouse for attention, if the wheels go round smoothly you're ahead of the field.
Wilf
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Juliet
May 1, 2020 8:24:34 GMT
Post by Roger on May 1, 2020 8:24:34 GMT
Hey Pete, photo posted just fine! Thank you. Which holes need to be closer, the holes in the rod? A method I used to set the distance, was to measure the distance between the axles. This should be the same distance between the holes on the rod. Does not matter what the drawing shows, the holes in rod must match the axle centers. I measured over the axles with them pushed together and another measurement over the axles with them pushed apart. You may have to get someone to manipulate the axles while you manipulate your caliper. The average of these two measurements is the center distance between the axles. (minus the diameter of one axle!) This is also the number for the distance between the holes in the rod. I assume you have a mill to accurately position the holes. Drill and ream one hole, turn the hand wheel the distance you have for the axle centers and drill and ream the other hole. No, you were right about the average... I use this method for finding the centres of any feature. It works even if the hole or axle sizes are different.
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Juliet
May 1, 2020 10:19:13 GMT
Post by ettingtonliam on May 1, 2020 10:19:13 GMT
Don't forget that before the introduction of alloy steel for the rods in full size, and more accurate manufacturing methods, the rods were adjusted to suit by taking them to the forge and having the smith stretch them or shorten them by 'bumping'.
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