Tom Senior Motor

It sounds to me as though one of the winding in the motor i connected the wrong way round. The end of one winding must be connected to the start of the next and so on.

I think that I've got eveything wired up now. I used the cable from an old iron because the insulation is silicone and heat resistant, that's why the new end tails are red, blue and green/yellow. Soft soldered them on, wrapped in PTFE tape and covered with heatshrink. There is continuity between the start and end of each of the tails with equal resistances of 12 Ohm. I tried several different ways of tying the wires to the windings: got some fibreglass twine but this kept breaking; then linen twine but wasn't happy with that; in the end I used the PTFE tape which is actually very strong when twisted and seems fine.

Now for the bit I am unsure of. My understanding is that the end of one winding must be connected to the start of another, so:

Ends are Yellow Y1, Y2 and Y3

Starts are Red R1, R2 and R3

There is continuity between the Y1-R1, Y2-R2 and Y3-R3 pairs respectively.

On the teminal block they must be wired so that different starts and ends are wired together, so I have wired them Y1-R3, Y2-R1 and Y3-R2

Now to buy a 1hp inverter - a TECO from Drives Direct or a WEG from Inverter Drives Supermarket https://www.inverterdrive.com/group/AC-Inverter-Drives-230V/WEG-CFW10-0040-S-2024-EOFAZ-230V-750W/

Edited By Hywel Evans on 17/11/2015 22:12:18

Your termination wiring scheme sounds good to me......

My advice,when you get your inverter, wired to the motor, use a 3 amp fuse in the plug....on initial start up.....

Drives Direct gets my vote...

Edited By John Rudd on 17/11/2015 22:24:37

Yes, point taken - stand well back and wear thick rubber boots . . .

Hi Hywell, Good job. Recommend that the new leads from winding ends to junction box also be laced to the existing windings to avoid movement and fatigue. Then some varnish on all modified wires. Polyurethane would be better than nothing.

So, the motor is now connected and the wires tied to the windings - I used some polyimide tape as well as PTFE - and varnish applied. Now I'm waiting for the inverter to arrive from Drives Direct before testing.

I am getting on with the rest of the refurb and, as these things tend to, it is escalating past my initial intentions. Completed an initial degrease and powerwash of the base, chiptray and other disassembled parts today ready for stripping and sanding. I have a couple of questions which I would be grateful for some advice on:

1. How do I remove the vertical leadscrew from the bottom of the knee? It seems to be located in a bushing which is attached to the underside of the slide by three allen head bolts. These are not easily accessible so I am thinking that taking these out is not the correct approach - or is it?

2. The leadscrews and worm gears were all liberally covered in grease. My understanding is that grease should only be used for bearings, and oil used for exposed parts like leadscrews and gears because it doesn't collect swarf like grease. Any opinions as to what to lube with on re-build?

3. The inside of the base was quite rusty and the suds tank full of who knows what. I have cleaned this out and powerwashed it. I could get it sandblasted but this means I would have to take it there and the cost is not trivial. Given that the inside will be hidden away so a perfect finish is not important, I just want to protect the metal so plan to treat it with kuurst, or similar, prime with zinc phosphate and paint on top with Stationary Engine Parts enamel. Does this seem a sound plan or is there a disaster lurking in it somewhere?

4. The outside surfaces I plan to strip with a polystrip disc on an angle grinder before priming and painting. I haven't done something like this before so hoping that it is a sensible approach . . .

Thanks

Hywel

Hi Hywel

I stripped mine using Nitromors paint stripper. Given the age of the machine I was concerned that the paint contained lead an didn't want to cover all the workshop and my lungs with the dust. In actual fact the paint came off easily. I painted the inside of the suds tank with a gloss paint, given that it wasn't going to be seen I used a tin of yellow that I had on the shelf.

I undid the casting from the base to release the vertical screw rather than the allen keys.

The gears and leadscrew on mine were coated in grease, plan to use oil on re assembly.

Tony,

I took your approach and hit it with paint stripper. It has gone pretty well with one problem. The aluminium rear cover has a thick black layer of filler type material over it, presumably to give a smooth finish to the rough casting. The paint stripper would take ages so I am in two minds whether to leave it, sand and prime over or remove it with the grinder but then have to fill all the bumps and hollows again. I am also concerned if it will react with the etch primer I intend to use. did you encounter this problem?

Hywel

Edited By Hywel Evans on 25/11/2015 08:54:10

I encountered the black filler like material on the inner sides of the drip tray as well. I removed it from the tray by scraper and a bit of heat. The rear cover I just sanded smooth and repainted, I didn't bother stripping it.

The inverter arrived so I put the motor back together and wired it all up temporarily. . . . and it worked! Turned it on and the motor started, increased the speed and the motor went faster. So far so successful - I will have to wait and see how it performs when hooked up to the mill after I finish painting and reassemble. Thanks to everyone for the excellent motor advice.

Hywel