I have a two-into-one issue with a couple of tachometer gearboxes, both of which are faulty in different ways but with which I hope to perform the two-into-one trick in order to obtain a functioning item. As the attached photo shows, one unit is missing an end cap and one of its pinions, whilst the other one is complete but the thread for the drive cable spigot has been stripped, so I would like to swap over the two cases. The job should be easy apart from the task of popping out the boxes' circular end-caps, which are an interference fit in their casings and which are cast from Mazak or a similar alloy with a high zinc content.
I would welcome any tips from anyone who has already tackled this sort of chore successfully.
Ian.
(North-East Yorkshire)
P.S: Thanks to John Holmes who quickly advised me that I'd set up this topic in an inappropriate forum!
Ian - Keep the pair of gears…
- Log in to post comments
Ian - Keep the pair of gears that are still a pair together and also keep any shims in their respective positions. When you then swap the pair into the replacement case you may need to juggle the shims as appropriate. You may need to centre pop the case and use a good suitable adhesive to refit the retaining end-caps. These are usually thin steel not 'monkey metal'. A good place to look for a replacement if all else fails is Speedograph Richfield - they are on t'interweb. Your gear pair should match your instrument. eg a 4:1 ratio clockwise instrument should have a 2:1 reversing gearbox. A tiny chisel and light hammer will help remove the end-caps Good luck, Howard