Hi l am a part missing out of a Dewhurst reversing switch it is the silver looking part which is shaped like a letter C with the ends turned up that goes across the middle and contacts the rollers there are 4 in all l could do with 2 but one would get me up and running Ken
I don't see how there can ever be four, IMHO that would just result in a dead short and big phut as your fuse blew. Is this what happened to the old ones I wonder ?
The contact bars you refer to as rollers were solid copper in the earlier switches and the spring links you refer are after were solid copper wire drilled and soldered to the bars. So they couldn't rotate. As the design wasn't changed, I am not convinced that the later steel contact bars are designed to act as rollers. This means you can just drill your bars and solder/braze links just like the early ones.
However, provided you are happy that they are not rollers and that there will be a bang if you try and fit four of these clips then I have a couple I can send you. I put a web page up a year ago with some wiring diagrams if it helps..
You will see that contacts 2 and 6 are not bridged - for obvious reasons. Also contacts 4 and 8 are not used for a normal single phase motor, so you only need two links.
The key to making these switches last is to use a seperate on/off switch (should be NVR type) and only use the Dewhurst to select the direction when the supply switch is off. That way the contacts won't burn and they will last forever.
Hi Steve l did not say that l was going to connect the 4 and l know that the rollers l said are not rollers but l was just trying to get over the parts l was looking for l do use a stop start button on my Dewhurst, the parts are for one that was on a lathe stand l bought which had no stop start and he had used the Dewhust which was obvious when l looked inside Thak you for you help .Ken
Seeing as you know what you are up to, I can supply two of the links (have sent e-mail). I posted my reply to the group as this comes up from time to time - 15 new hits on the Dewhurst web-link shows you are not the only one interested. Also I noticed a NEW Dewhurst switch for sale on eBay, and its got a silver top - I don't remember seeing a new one before - or a silver top one.