RMweb Gold Stubby47 Posted January 18, 2018 RMweb Gold Share Posted January 18, 2018 As part of my Cameo entry DM Four Mill Something, I need to make some working blast doors. These will be servo controlled, so I've joined MERG and bought a few of the PMP (Pocket Money Project) kits to experiment with. As I need to make a prototype working door, it seems to make sense to make it into a Cake Box Challenge entry as well. So, this entry will consist of a short piece of inlaid track (possibly dual gauge) which enters an underground storage area, which is protected by a blast door. The door will slide open sideways, powered by a cam & wire from the servo, and possibly with a working warning light as well. It will be powered from a simple 9v dc battery, hidden somewhere in the storage area. I've made a test start on the door hanging mechanism, using U and Z plasticard struts, but need to size the opening and door correctly, plus work out how much extra room I need to accommodate the open door, and how best to hide the operating gubbins. 1 Link to post Share on other sites More sharing options...
KNP Posted January 18, 2018 Share Posted January 18, 2018 Sounds interesting......keep us posted as work progresses I assume if it doesn't work as envisaged will it be renamed 'blasted door' .............? After our earlier chat how are the other 5 CBC's and 4 cameo layouts proceeding? Link to post Share on other sites More sharing options...
RMweb Gold Stubby47 Posted January 18, 2018 Author RMweb Gold Share Posted January 18, 2018 It will work, it will, it will.... I need to get back into the mindset of modelling, so the start of DM 4mm is helping. As this is also progressing that project, I'm feeling more enthused. Despite creating a suitable work space in the garage, it's been too cold to do much in there. Hopefully I can sort out some mini tasks which means I can work indoors. Progress will be posted. Link to post Share on other sites More sharing options...
KNP Posted January 18, 2018 Share Posted January 18, 2018 It will work, it will, it will.... I need to get back into the mindset of modelling, so the start of DM 4mm is helping. As this is also progressing that project, I'm feeling more enthused. Despite creating a suitable work space in the garage, it's been too cold to do much in there. Hopefully I can sort out some mini tasks which means I can work indoors. Progress will be posted. Of course it will... My advantage is I have the layout and work area in the 4th bedroom so, without rubbing it in, it's lovely and warm in there. 2 Link to post Share on other sites More sharing options...
RMweb Premium St Enodoc Posted January 18, 2018 RMweb Premium Share Posted January 18, 2018 Sounds interesting......keep us posted as work progresses I assume if it doesn't work as envisaged will it be renamed 'blasted door' .............? After our earlier chat how are the other 5 CBC's and 4 cameo layouts proceeding? Speaking of which, where are the other 5 CBCs? Link to post Share on other sites More sharing options...
RMweb Gold Stubby47 Posted January 18, 2018 Author RMweb Gold Share Posted January 18, 2018 Speaking of which, where are the other 5 CBCs? Er, in various stages of progress (some physically, some mentally). They'll all get done in time... Link to post Share on other sites More sharing options...
RMweb Premium St Enodoc Posted January 18, 2018 RMweb Premium Share Posted January 18, 2018 Er, in various stages of progress (some physically, some mentally). They'll all get done in time... Any links? Link to post Share on other sites More sharing options...
RMweb Gold Stubby47 Posted January 19, 2018 Author RMweb Gold Share Posted January 19, 2018 CBC1 - Victoria Wharf CBC2 - From a carriage window CBC3 - The caravan park CBC4 - The Engine Shed CBC5 - Bullhead Link to post Share on other sites More sharing options...
RMweb Premium St Enodoc Posted January 19, 2018 RMweb Premium Share Posted January 19, 2018 CBC1 - Victoria Wharf CBC2 - From a carriage window CBC3 - The caravan park CBC4 - The Engine Shed CBC5 - Bullhead Thanks Stu. I was following 2 and 5, now following 1, 3 and 4 as well. Link to post Share on other sites More sharing options...
RMweb Gold Stubby47 Posted January 19, 2018 Author RMweb Gold Share Posted January 19, 2018 The prototype door and wall was made from off cuts of 40thou plasticard. I salvaged the door and trimmed it down to a size which leaves enough space at the base to let the inlaid rails underneath. This model's walls are made from Slater's block sheet. The layout walls may well be Scalescenes or my own design of printed paper. This is the progress so far: 15 Link to post Share on other sites More sharing options...
RMweb Gold Stubby47 Posted January 20, 2018 Author RMweb Gold Share Posted January 20, 2018 Next steps include priming the walls and door, and then installing the unit in a baseboard. This will allow me to lay the track, add the platform, add the surrounding walls and then consider how and where to mount the servo. Link to post Share on other sites More sharing options...
Guest ShildonShunter Posted January 21, 2018 Share Posted January 21, 2018 Hi Stu looking good mate and I have just been looking at the links to your other cake box challenges and your modelling and attention to detail is brilliant. Link to post Share on other sites More sharing options...
KNP Posted January 21, 2018 Share Posted January 21, 2018 Like the look of this concept, very promising. Will there be sound effects of a heavy door sliding? Link to post Share on other sites More sharing options...
RMweb Gold Stubby47 Posted January 21, 2018 Author RMweb Gold Share Posted January 21, 2018 I have thought about sound effects: a siren as the door starts to move, a hiss of air as the seal is broken and the rumble of the door being opened. Whether I add these here, or to the layout, I'm not sure yet. 2 Link to post Share on other sites More sharing options...
Gypsy Posted January 21, 2018 Share Posted January 21, 2018 Looks interesting - I've had a similar idea for a shunting puzzle I'm planning. I apologise in advance for any plagiarism! Link to post Share on other sites More sharing options...
Arthur Posted January 21, 2018 Share Posted January 21, 2018 Have you seen this book Stu? It’s not cheap but is packed with photos and info. There’s a second one on Cold War bunkers. Nick Catford has spent years, collecting info., exploring and photographing them. https://www.amazon.co.uk/Second-World-War-Secret-Bunkers/dp/099285542X/ref=pd_lpo_sbs_14_img_2?_encoding=UTF8&psc=1&refRID=VM3YERW7GHKDJ5S9XZ14 . Link to post Share on other sites More sharing options...
RMweb Gold Stubby47 Posted January 21, 2018 Author RMweb Gold Share Posted January 21, 2018 No, not seen that book, many thanks. Most of my research has been based on Dean Hill http://www.subbrit.org.uk/sb-sites/sites/d/dean_hill_rnad/index.shtml and the store at Ernesettle, Plymouth. The rest is my usual make-it-up-as-I-go-along research. Link to post Share on other sites More sharing options...
RMweb Gold Stubby47 Posted January 21, 2018 Author RMweb Gold Share Posted January 21, 2018 Meanwhile, the MERG servo test board has been complete and is working. This board will allow me to test the cam operation in a slow, controlled manner, prior to installing the proper control board. Link to post Share on other sites More sharing options...
RMweb Gold Stubby47 Posted January 23, 2018 Author RMweb Gold Share Posted January 23, 2018 The second MERG kit was completed and tested yesterday. This will be installed with the servo as the finished controller. The first module will let me operate the servo at slow speed and will let me stop the servo/door at any point to assess operation. Then once I'm happy with the mechanics, the 2nd module will be used just to open/close the door. 2 Link to post Share on other sites More sharing options...
Bergmann Posted January 23, 2018 Share Posted January 23, 2018 I like what you're doing, in my convent model I also have lots of animations. I always test something like this with a very simple Servotester with a middle position I can adjust the mechanics best. So I then have enough servo-way on both sides. Then the connection is made to the servo I use a OC32 from Dinamo a I can combine other things at 32 I/O. Soon hopefully more, in my cakebox post. 1 Link to post Share on other sites More sharing options...
RMweb Gold Stubby47 Posted January 24, 2018 Author RMweb Gold Share Posted January 24, 2018 Here is a quick, unedited, video of the door sort of working: https://youtu.be/IvyOhy0Vhus 3 Link to post Share on other sites More sharing options...
Bergmann Posted January 24, 2018 Share Posted January 24, 2018 Have you ever thought of using a cable or a steering wheel. Such a drive shown by you will not result from my experience. Look at my garage door there is even the handle to open. https://youtu.be/aKRTBzxXGRg The gate is opened via a drive disc on the servo and a push rod. 2 Link to post Share on other sites More sharing options...
RMweb Gold Stubby47 Posted January 24, 2018 Author RMweb Gold Share Posted January 24, 2018 Thanks for the video - very clever. I think the method I'm trying will work, the wire needs to be stiffer and at the moment the motion of the door is not in line with the arc of the servo horn. Further experimentation will improve things. Link to post Share on other sites More sharing options...
RMweb Gold Stubby47 Posted January 26, 2018 Author RMweb Gold Share Posted January 26, 2018 Reflecting on what's been done so far, I think the overall concept will work. What needs to be improved is the slide mechanism - it needs support either side of the servo arm connection, which itself needs a stiffer rod. The next version will be better. I'm still musing on how to improve the blast door around the track work, what I really want is a second moving part which raises a narrow strip of track once the door has fully opened, but that would either be complicated mechanically or mean doubling the servos. Link to post Share on other sites More sharing options...
riscosuser Posted January 26, 2018 Share Posted January 26, 2018 Reflecting on what's been done so far, I think the overall concept will work. What needs to be improved is the slide mechanism - it needs support either side of the servo arm connection, which itself needs a stiffer rod. The next version will be better. I'm still musing on how to improve the blast door around the track work, what I really want is a second moving part which raises a narrow strip of track once the door has fully opened, but that would either be complicated mechanically or mean doubling the servos. I looked at this the other day thinking a rack & pinion arrangement would be much smoother. Worth considering using mechanism out of an old PC CD/DVD drive. Built-in motor, rack & lifting device! The disadvantage being you would need approx 1.5 inches under the base. Use the eject button as an open/close button. Link to post Share on other sites More sharing options...
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