What core cable.

Me again with another beginners question :- I have just got myself a Gryphon 0.25 hp motor. I want to keep it as a spare for my ML7 lathe.

it has come after having had new bearings fitted and runs very quiet and smooth.

it also came with a 3 core cable and plug and runs in one direction only.

I would like to rewire it so I can select Fwd/Rev using a drum switch.

I have a drum switch with 2 rows of 4 contacts.

the motor has 4 terminals. Z1. Z2. A1. A2

A1 seems to be connected to Z1 via a copper link

A2 seems to be connected to Z2 via a copper link

how ‘very simply please’ do I connect the Mains, Drum switch and motor together to achieve what I want and how many cores does the cable need from motor to switch, and if possible how thick do the cores need to be ? I.e. .75mm,1mm, 1.5mm

long question but I am learning and you have sorted my previous 2 ??s very quickly

thanks

That's possibly a bit small for a ML7, however...

Does it have an obvious capacitor? If it does then it should be reversible in the way you want.

As for using it as a spare, induction motors almost never give up unless either the bearings wear out or the start/run capacitor(s) give up, usually the latter. So your main motor is very likely to be easily repairable if it does go.

Thanks,

yes it does have a capacitor…. The motor is I understand original to a ML7. The motor on my lathe was new a month ago and gave up….it would only go in reverse…..see my previous topic…the manufacturer is replacing it for me.

Well without knowing exactly how the cap is connected I'm not sure how you reverse it, but I would guess that one winding must be Z1-Z2 and the other A1-A2, and one of these has the cap in series. At the moment it's connected Z1-A1 and Z2-A2, I would guess that if you connect Z1-A2 and Z2-A1 it would run in reverse as you have reversed one winding's sense relative to the other. As for the number of cores, there are only 4 terminals (plus earth presumably) so it can't be more than 4! As for size the same size as on your main motor. Wiring these funny switches I have no knowledge of I'm afraid.

Here you go, not only will this site show you how to refurbish a Dewhurst switch, it will also show how to wire one.
https://misterlinnsworkshop.wordpress.com/2014/03/08/dewhursts-big-switch/

Re. the number of cores in the cable, I'd go for 5 core, as you need 4 plus an earth.
You could use 4 core and earth separately, but if you need to buy some cable anyway..................

Bill

Edited By peak4 on 02/09/2022 16:14:10

The capacitor is connected to Z1 & Z2. Red wires

the windings to A1 & A2 Black wires

Peak4….great, thanks…..

Edited By Haydn Callow on 02/09/2022 16:22:10

A .25Hp motor will only do small work on an ML7 ! Should be 0.5Hp Start windings should be blue and Yellow, run windings should be red and black. It sounds like a dewhurst drum switch. A1 and A2 run and Z1 and Z2 start ' 1,2,3,4, on left 5.6.7.8. on right of switch.. Live to No1 Neutral to No3 earth to the earth stud or bear metal point VITAL ! A1 to No5, A2 to No 7, Z1 to No6 and Z2 to No2. IF the direction is wrong on the switch swap No6 and No2.. ONLY use this switch to change direction of rotation, stop and start with a seperate switch. NEVER change direction whils the motor is still turning ! . Good luck Noel.

Edited By noel shelley on 02/09/2022 17:33:23

Thanks for that….it’s not a Dewhurst but very similar…..made in China , green oblong….plenty to see on eBay….dammed if I can work out how to post a picture on here. I’m on a iPad

To answer your question 5 core 1.5 mmsq Noel..

I would think 1mm ^2 or even less,is likely sufficient. It’s not much bigger than a good sized soldering iron!🙂

I'd think twice before fitting a motor that small - it will limit how fast you can work, and the motor will often be pushed to the max. Half to one horse-power is more usual, and a boy racer might go bigger still...

All good and working well, thanks everyone

Hope you are not using the drum switch as the main on/off. That will burn the contacts - you need to get a 'no volt release' unit. Probably got that in the Myford wiring but in case you decided to use this motor on some other little project.