Since mid-June 2000, Dingham has had electromagnets available at £5.00 each, including UK post and packing. The magnets are produced by fitting an extended pole piece to industrial-quality solenoids. See electromagnet product page for further details.
Yes. Mr Jim Mitchell, a user of 7mm Dingham Autocouplers has designed a DIY Electromagnet. Jim very kindly sent me one of his magnets all the way from Australia for testing. Instructions for making the magnets and more information can be found elsewhere on the site. Just follow the hyperlink above.
Only in certain circumstances, because all vehicles which are propelled over a permanent magnet will be uncoupled and will stay uncoupled.
However, if there is a location on the layout where you always want to uncouple (e.g. a loco on a passenger train arriving in a terminal station), then it may be possible to use a permanent magnet. So long as the coupler is under tension as the train comes to a halt over the magnet, it will remain coupled. The loco should then be reversed about 3mm, when uncoupling will occur. This movement is quite prototypical because the loco would be reversed to compress the buffers so as to assist slackening and uncoupling of the screw-link coupler.
There's another way in which you might use permanent magnets. You could install a mechanism to raise and lower the magnet. This will need some experimentation to find the lowered position where the magnetic field is not strong enough to attract the dropper and actuate the couplings. The raised position should be as near the top surface of the sleepers as possible.
When using permanent magnets, be sure to mount them so that a magnetic pole points upwards. Some bar magnets have the poles at the ends and some on the flat sides. Just feel around with a piece of iron or steel to find where the magnetic field is strongest.
I want to fit my Dingham Autocouplers using springs and split pins. Where can I get suitable springs?
This method of attaching the couplers is not recommended because it gives a less positive location than gluing or soldering. However, if you really do want to use springs and split pins, I can supply suitable springs for fitting the 7mm couplers at £2.00 for 12, including UK P&P. Note that the pack includes springs only - not the split pins. This is because 1/32in split pins are easily available from outlets such as good hardware shops, whereas suitable springs are difficult to find. A piece of wire about 0.8mm diameter and 15mm long, bent to a shallow V can be used instead of a split pin.
At present, I am not proposing to supply springs suitable for the 4mm couplers because this method of fitting seems less popular in the 4mm scales. I may change my mind if customers tell me I should but I'll need some persuading because I don't enjoy counting springs into dozens.
If you use the spring and split pin method, it is highly recommended that you also use the etched drawgear endplates (coupler pockets) supplied on the Dingham fret. The couplers are a good fit in the etched slots, whereas they are likely to be a sloppy fit in the slots in plastic, white metal or etched kit buffer beams. Before fitting the etched coupler pockets, carefully remove any existing moulded pockets, otherwise the hooks may protrude too far from the headstock.
I use Carrs Metal Black for Nickel Silver, and I normally blacken the coupler components after soldering and folding-up but before assembling the components. Carrs Metal Black for Nickel Silver is available from many model shops and mail order outlets or indeed, directly from its manufacturer C+L Products, who advertise regularly in the model railway press.
Remove any excess solder from the components with files and a glass fibre pencil, then shake the components in washing-up liquid in hot water for a few minutes to degrease. Then, immerse the components a few at a time in the blackening solution. Agitate or brush the components so that bubbles do not cling to either the upper or lower surfaces of the components. If you do not remove the bubbles, you will have unblackened spots on your couplers. Remove the components from the blackening solution when they are dark-brown to black and drop them in clean water to remove excess blackening solution and stop the chemical reaction.
If blackening occurs more quickly than 10 - 20 seconds, the coating will be brittle and will flake off easily. If this happens, dilute the blackening solution, until blackening takes place more slowly and the blackened coating is thinner and stronger.
Other methods of blackening are described on the feedback page.
Unfortunately, no. Dingham is a one-man operation. The bureaucracy and costs involved in setting up and operating a Credit Card facility would overstrain limited resources. Payments from UK customers are acceptable by cheque, drawn in favour of T Shaw, or by postal order. Overseas customers should enquire about prices and payment method.
However, I can now accept payments via PayPal from both UK and overseas customers. This allows customers to transfer funds by credit or debit card to PayPal and I can then collect from PayPal.
A 4mm version of the coupler has been available since July 2002. I would like to thank the many people who have asked this question for their patience during the months it took me to develop a reliable 4mm version. It involved a complete re-design and it was far from easy.
A method of making couplers with both a loop and a latch is given in the 7mm instructions. Theoretically, fitting such double-ended couplings at both ends of locos which are turned should solve the problem, but it has to be said that the couplers do not work very well if this method is employed. There's simply too much friction between the two loops to allow reliable uncoupling. (It must also be said that this applies to all couplers based on the loop and latch principle).
There are other possible ways around the problem in certain circumstances. For example, there are many end-to-end layouts with a shed and a turntable on which only certain tender passenger engines on certain trains are turned. Passenger tank engines and goods locos are not turned. In such a case, the locos which are turned can be fitted with a hook-with-latch at both ends and the rakes of coaches they work can have hooks with loops at each end. Further development of this idea will allow tail loads to be added to passenger trains, etc.
No. The Dingham Autocouplers rely on the buffers on vehicles for buffing, just as 3-link and screw couplings do. This means that restrictions on propelling and pulling trains through trackwork are the same as for 3-link/screw couplings. The only ways buffer locking can be prevented by an automatic coupler is to build a centre buffer into the design of the coupler or to have an arrangement where a wire is soldered between the buffer heads. I didn't want to take either of these routes when designing the Dingham couplers because, in my view, they are visually obtrusive.
You can fit them to the hook with type 1 latch by drilling a hole through the hook in the right place. I didn't etch a hole because I reasoned it would be redundant as far as most users are concerned and also might weaken the hook. You cannot fit dummy 3-links to either the hook with loop or hook with type 2 latch because it would prevent the coupler working.
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