RMweb Gold The Stationmaster Posted July 2, 2022 RMweb Gold Share Posted July 2, 2022 2 hours ago, FarrMan said: I would suggest a bit of drafting tape (or masking tape) either side would reduce unwanted breakout and give a better grip to the point of the bit. Too fast a drill speed and you will melt the perspex, so a slower speed would be preferable. If it is a large hole that you need, start with a small bit and gradually work up to final size. Hope it works OK for you. Lloyd I'd definitely go for taping as acrylic does have an inclination to split/shatter when being drilled (although that might be doen to either cheap Hobbycraft acryliceor my hamfisted drilling or even a combination of the two). I've wondered about using a glass/tile drill bit instead of a twist drill but have never tried so I don't know if it's a sensible aternative 1 2 Link to post Share on other sites More sharing options...
RMweb Premium St Enodoc Posted July 2, 2022 Author RMweb Premium Share Posted July 2, 2022 7 minutes ago, The Stationmaster said: I'd definitely go for taping as acrylic does have an inclination to split/shatter when being drilled (although that might be doen to either cheap Hobbycraft acryliceor my hamfisted drilling or even a combination of the two). I've wondered about using a glass/tile drill bit instead of a twist drill but have never tried so I don't know if it's a sensible aternative I don't mind if it cracks but if a corner splits off or the sheet shatters I'll go to Plan B, which is 4mm MDF... 2 3 Link to post Share on other sites More sharing options...
Mulgabill Posted July 2, 2022 Share Posted July 2, 2022 16 minutes ago, St Enodoc said: I don't mind if it cracks but if a corner splits off or the sheet shatters I'll go to Plan B, which is 4mm MDF... Hi John - for once something I have a (very) little experience with. I did spend nearly a year in a plastic fabrication co, and might just remember a little of the techniques. 1) Acrylic sheet does not like heat, so keep your drill bit cooled, by dipping in water, frequently. 2) Drilling is also inclined to chatter, which in turn causes stress fractures. These in turn can lead fractures later. Where I worked new drill bits were treated with a file, to rempve the sharp edge on the tip. Slow drill speed, with an "old" bit, should achieve similar results. (and don't push too hard). All the best TONY 3 1 1 6 Link to post Share on other sites More sharing options...
FarrMan Posted July 2, 2022 Share Posted July 2, 2022 3 hours ago, FarrMan said: I would suggest a bit of drafting tape (or masking tape) either side would reduce unwanted breakout and give a better grip to the point of the bit. Too fast a drill speed and you will melt the perspex, so a slower speed would be preferable. If it is a large hole that you need, start with a small bit and gradually work up to final size. Hope it works OK for you. Lloyd Not sure about acrylic, but perspex is best done with a sharp knife along the line of cut and then bend it over a rigid edge. It just snaps off along the line. Use knife firmly, as you want to do a bit more than just score the surface. If you have a wee bit spare, you could try it and see. If you need to use a saw, then I would think as fine a tooth saw as you can get. Again to avoid getting it too hot, do it in short stages, or cool the blade frequently. Talking of avoiding undue heat reminds me of a story I heard about a contractor cutting up an old underground petrol tank (i.e. BIG). He should have been using a hand saw, but chose to use a power saw instead. The Petroleum Officer was just around the corner when he heard the explosion. The contractor went up to an altitude of 15 feet - he went up white and came down black! His first words to the Petroleum Officer were 'Does this mean that I am taken off the list of approved contractors?' Lloyd 4 1 4 1 Link to post Share on other sites More sharing options...
FarrMan Posted July 2, 2022 Share Posted July 2, 2022 56 minutes ago, St Enodoc said: I don't mind if it cracks but if a corner splits off or the sheet shatters I'll go to Plan B, which is 4mm MDF... When using MDF, remember that the saw dust can be carcinogenic. Best done outside if possible, with suitable respiratory protection. Lloyd 4 1 Link to post Share on other sites More sharing options...
RMweb Premium Tim Dubya Posted July 2, 2022 RMweb Premium Share Posted July 2, 2022 (edited) 16 minutes ago, FarrMan said: When using MDF, remember that the saw dust can be carcinogenic. Best done outside if possible, with suitable respiratory protection. Lloyd Absolutely, I use one of these when I'm cutting anything, also sanding etc. Edited July 2, 2022 by Tim Dubya Photo, + they do a smaller size for little heads. 4 1 2 Link to post Share on other sites More sharing options...
RMweb Gold 5BarVT Posted July 2, 2022 RMweb Gold Share Posted July 2, 2022 11 hours ago, ianathompson said: I would sooner settle for sloppiness than the need to call every train past a signal at danger! I’m sure you would, and I’m equally sure S&T wouldn’t because sloppiness becomes failed locking much sooner. :-) Speed of getting it working to your satisfaction is what matters. Interesting that it took a couple of shifts before it seized up. Paul. 2 1 Link to post Share on other sites More sharing options...
RMweb Premium ianathompson Posted July 2, 2022 RMweb Premium Share Posted July 2, 2022 2 hours ago, 5BarVT said: Interesting that it took a couple of shifts before it seized up. Quite agree with this comment. As a relief I was not working the box in question when the work was done. It was, I was assured, properly tested and signed off as 'in order'. Presumably the temperature changed significantly during the interim. Ian T 2 3 Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted July 2, 2022 RMweb Gold Share Posted July 2, 2022 2 hours ago, 5BarVT said: I’m sure you would, and I’m equally sure S&T wouldn’t because sloppiness becomes failed locking much sooner. :-) Speed of getting it working to your satisfaction is what matters. Interesting that it took a couple of shifts before it seized up. Paul. When the Nantgarw bran ch from Taffs Well was singled back in the 1970s we had a lot of problems with the FPLs on the new facing crossover at Taffs Well because of the S&Ts difficulty in getting them adjusted. It took a couple of weeks, with some occasional strong words on my part to get it to the Signalmen's (and my) liking because it inevitably became a very hard pull to get the FPL bolts to engage. The reality is that sometimes these things can happen and it can take time for new work to bed-in and get the adjustment right and while it might mean hard pulling that's a lot better than dealing with sloppiness somewhere in the mechanism (i've encountered some of that too and I know which I prefer). 5 5 1 Link to post Share on other sites More sharing options...
aardvark Posted July 3, 2022 Share Posted July 3, 2022 Hope you're keeping your head above water down there. 1 1 Link to post Share on other sites More sharing options...
RMweb Premium St Enodoc Posted July 3, 2022 Author RMweb Premium Share Posted July 3, 2022 (edited) 56 minutes ago, aardvark said: Hope you're keeping your head above water down there. Yes, 200m above sea level so if we flood others have far bigger problems... Fires are a greater risk for us. A couple of years ago, if the Gospers Mountain fire had jumped the Hawkesbury River we might have been in trouble. Edited July 3, 2022 by St Enodoc 2 2 2 Link to post Share on other sites More sharing options...
aardvark Posted July 3, 2022 Share Posted July 3, 2022 2 hours ago, St Enodoc said: Yes, 200m above sea level so if we flood others have far bigger problems... I did think, after posting, that as a grand sweeping generalisation, we model railway tragics are probably not of a socio-economic demographic that would make us likely to be victims of flooding, i.e. we live in better houses that aren't on flood plains. Having written that, I remind myself that nothing is normal any more. Also, I hear that there's a bit of rain about, and roofs sometimes leak, even new ones. 4 1 Link to post Share on other sites More sharing options...
RMweb Premium Popular Post St Enodoc Posted July 3, 2022 Author RMweb Premium Popular Post Share Posted July 3, 2022 No problems with cutting and drilling the acrylic sheet. I used a hacksaw with an 18tpi blade and drilled the holes using a hand brace, going nice and slowly in each case. I didn't bother taking the protective paper off afterwards, as the locking will all be hidden once the frame is installed I then filed the locking pins to length and reassembled the frame, with a bit more fettling as I went along. Finally, I fitted the lock cover, the locking bar springs and their retainers. You might wonder why there are two vacant holes at the bottom of the lock cover. There are two reasons. First, I marked the hole in the wrong place so had to drill another. Secondly, and this was a surprise, there were only five M3 20mm CSK screws, instead of six, and a spare M3 16mm CSK one, which of course is too short. I'll try to find a suitable replacement in my nuts, screws, washers and bolts box. I'd like to have been able to say that the mechanical work is now complete and before I fitted the locking bar springs I thought it was. However, once the springs were fitted two levers refused to move. I'll have to take the springs off and work out why. Assuming I'm successful, I'll then dismantle the locking for the final time, apply a dry PTFE lubricant to all the moving and sliding parts, then reassemble it. The frame won't be commissioned before our next running session in two week's time but I'll probably mount it in place on the layout anyway, so that folk can have a play. 22 2 1 Link to post Share on other sites More sharing options...
RMweb Premium St Enodoc Posted July 5, 2022 Author RMweb Premium Share Posted July 5, 2022 On 03/07/2022 at 17:35, St Enodoc said: I'd like to have been able to say that the mechanical work is now complete and before I fitted the locking bar springs I thought it was. However, once the springs were fitted two levers refused to move. I'll have to take the springs off and work out why. I've had a quick look and I think that I can do two things. The first is to increase the gap between the spring retainer plates and the frame, which will give the conditional locking bars more room to move, as the springs are almost fully compressed in both positions at the moment. The other is to ease the square notches on tappets 4 and 27 where they engage with locking bar D, by filing a slight bevel on their edges. 1 1 6 Link to post Share on other sites More sharing options...
RMweb Gold Regularity Posted July 5, 2022 RMweb Gold Share Posted July 5, 2022 1 hour ago, St Enodoc said: I think that I can do two things. Oh, I am sure you can do more than two things. The question is, can you do two (or more) things at the same time? 8 2 Link to post Share on other sites More sharing options...
RMweb Premium St Enodoc Posted July 5, 2022 Author RMweb Premium Share Posted July 5, 2022 3 hours ago, Regularity said: Oh, I am sure you can do more than two things. The question is, can you do two (or more) things at the same time? You'd be surprised. 1 3 6 Link to post Share on other sites More sharing options...
RMweb Gold Regularity Posted July 5, 2022 RMweb Gold Share Posted July 5, 2022 6 hours ago, St Enodoc said: You'd be surprised. I certainly would be, given our relative geographic locations! 2 1 Link to post Share on other sites More sharing options...
RMweb Premium St Enodoc Posted July 8, 2022 Author RMweb Premium Share Posted July 8, 2022 (edited) Only a short session today after fitting a new seal to the bottom of the workshop door, where some water had seeped in during the wild wind and very heavy rain we had last week. I did have time to open up the interlocking and ease all the square notches by filing a slight bevel on each corner. All the levers now work when they should, although some are a little, erm, "notchy". More importantly, nearly all the levers don't work when they're not supposed to (the true meaning of verification). One is free when it should be locked but I don't think it will affect operation, so other than going through the charts and tables to see if there's an obvious reason I'm going to leave it all alone. No photos today but I might take a couple tomorrow, before and after I've lubricated the interlocking, which will indeed mark the end of the mechanical work. Edited July 8, 2022 by St Enodoc minor clarification 14 3 Link to post Share on other sites More sharing options...
RMweb Gold 5BarVT Posted July 8, 2022 RMweb Gold Share Posted July 8, 2022 2 hours ago, St Enodoc said: One is free when it should be locked Details, details!!! Unless its in the conditional locking the converse should also be free when it should be locked. I thought about asking what the travel on the tappets is when you mentioned your filing error on 17 (modratec) to see if that would free up something irregularly but having looked at the locks spreadsheet for the both ways locks it looks like the travel is two locking bars. If I’m right, that means your false notch on IJ moves to JK which doesn’t exist so won’t release anything irregularly. I was puzzled by what looked like a pin on IJ at the notch in 17 but further inspection indicates it’s the ‘down’ pin for the lock on 18. Thank you for the fun mental exercise provided! Paul. 5 1 Link to post Share on other sites More sharing options...
RMweb Premium St Enodoc Posted July 8, 2022 Author RMweb Premium Share Posted July 8, 2022 (edited) 2 hours ago, 5BarVT said: Details, details!!! Unless its in the conditional locking the converse should also be free when it should be locked. I thought about asking what the travel on the tappets is when you mentioned your filing error on 17 (modratec) to see if that would free up something irregularly but having looked at the locks spreadsheet for the both ways locks it looks like the travel is two locking bars. If I’m right, that means your false notch on IJ moves to JK which doesn’t exist so won’t release anything irregularly. I was puzzled by what looked like a pin on IJ at the notch in 17 but further inspection indicates it’s the ‘down’ pin for the lock on 18. Thank you for the fun mental exercise provided! Paul. Thanks Paul. That's correct regarding the travel. Each locking bar is approx 4.5mm wide and the lever throw is approx 9mm. I can't remember which lever seems to be wrong - its twenty-something - but everything's out in the workshop at the moment. When I've had a closer look and a think I'll follow up with you separately. Edited July 8, 2022 by St Enodoc speling 1 3 Link to post Share on other sites More sharing options...
Martin S-C Posted July 8, 2022 Share Posted July 8, 2022 On 29/06/2022 at 12:31, St Enodoc said: I've now restored all my images on this topic back to the start of June 2021. Once I'd got into the routine, it was quite therapeutic. In fact, in a way, I'm sorry it's finished (no I'm not, don't be ridiculous). I was hoping some server fixer-upper wizardry would do that. Are you *quite* sure we need to do it ourselves? *Shudders at the thought of going back to Feb 2018 on my thread* 2 2 Link to post Share on other sites More sharing options...
RMweb Premium St Enodoc Posted July 9, 2022 Author RMweb Premium Share Posted July 9, 2022 13 hours ago, Martin S-C said: I was hoping some server fixer-upper wizardry would do that. Are you *quite* sure we need to do it ourselves? *Shudders at the thought of going back to Feb 2018 on my thread* Unfortunately, I think I'm right. As I understand it, all images posted between June 2021 and March 2022 inclusive are gone and will need to be restored by the posters concerned. Images from May 2021 and earlier will be restored automatically, although that process seems to be extremely slow at the moment. 5 2 3 Link to post Share on other sites More sharing options...
aardvark Posted July 9, 2022 Share Posted July 9, 2022 1 hour ago, St Enodoc said: although that process seems to be extremely slow at the moment. I think "extremely" is an understatement. 4 Link to post Share on other sites More sharing options...
RMweb Premium Popular Post St Enodoc Posted July 9, 2022 Author RMweb Premium Popular Post Share Posted July 9, 2022 After a brief interlude when one of the operating team was so keen to join in the running session that he turned up a week early, I finished the mechanical work on the lever frame today. This involved removing all the interlocking, wiping off any residual dust/filings and giving each part, as I reassembled it, a light spray of dry PTFE lubricant. You can see that I did, after all, remove the paper from the acrylic sheet, because I wasn't sure how it would behave if the lubricant got to it. Having removed the lower sheet there didn't seem to be any point keeping the upper one, so here's the complete frame, complete mechanically, in Modratec orientation as built... ...while flipping it through 180 degrees lets us see it in layout orientation. Next, I took the frame over to the layout and tried it in position. This is the final position laterally but I won't fix the final fore-and-aft position until I've fitted the electrics, specifically the two Eemecks that sit at the rear of the frame as we see it here. I'll then push the frame back as far as I can without them fouling the L-girders. This is the signalman's-eye view. The frame will sit slightly lower than that at Porthmellyn Road but there will still be plenty of room for the signalman's knees. Now, yesterday I said that I'd continue the discussion with Paul @5BarVT about the locking errors off line but, as I know that others here are interested in this sort of thing, I changed my mind. The errant lever appears to be 24 (Modratec numbering). Levers 7 and 24 should lock each other but don't - 7 can be reversed when 24 is normal, which is wrong. Likewise, levers 19 and 24 don't lock each other either - 19 can be reversed when 24 and 21 are both reversed. Additionally, when 25 is reversed it doesn't lock 22 normal when 24 is reversed and 21 normal. It's all too hard for me to work out, I'm afraid, and anyway it's too late to change anything, so I'll live with it. Once I've done the pulling lists nobody should need to worry about it in any case. Tomorrow I might start the electrics - making up the switch units that are activated by the bottom ends of the levers - or I might just tidy up the railway room ready for next week and play trains for a while. 16 6 Link to post Share on other sites More sharing options...
RMweb Premium Barry O Posted July 9, 2022 RMweb Premium Share Posted July 9, 2022 I vote for playing trains!! Baz 4 10 Link to post Share on other sites More sharing options...
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