BKB Startomatic spins the wrong way. Can it be reversed?

[Ianhw77k]

Hello, my name is Ian. When it comes to the technical side of generators I have to admit, I'm a bit of a layman so please excuse my non technical terms.

I am currently restoring a Coventry Victor WD1 single cylinder diesel engine in the hope of using it for back-up power in case of a lights out situation. Mainly for the freezers as they are full of next year's sausage supply.
I recently spotted a BKB Startomatic generator on ebay and paid what I thought was a fair price, it needs some attention but that is not outside the capabilities of me or my brother. The main problem I have is that when I got it home, I realised that it spins the wrong way for the engine

I could try to direct couple it but that is rather a lot of engineering work and I have been warned that the pulses created by the single cylinder thumper could cause problems. I could also incorporate a layshaft into the design so I can mount the generator pulley on the other side and get the correct rotation but I would also like to show this unit at vintage engine rallies and this could look a bit cumbersome.

My question to you people in the know is; can I easily reverse the rotation of this generator so I don't have to follow either of the courses of action above?
I assume the 230V alternator wouldn't be a problem but it is the starter and dynamo I am more worried about. I also don't know if it is a 12V or 24V starter, it spins with 12V put into it but that doesn't really prove anything. That's another question for another time though.

Thanks in advance for any advice

[hiker]

would this work ?

[dnix71]

The Startomatic I saw in a closed eBay UK listing had a pulley already. The engine pulley will either be behind the genset or to the side and behind depending on the needed rotation. Behind is a squarer arrangement.

[Mary B]

couple pulleys would not look that cumbersome, if you want it to look vintage use something from that era.

[Ianhw77k]

OK, so no easy option for getting this thing to spin the other way?

Also, you managed to find the picture of the exact one I bought lol. I guess I'm back to the layshaft idea. Thanks for the responses.

[dnix71]

You are British. Unfortunately, we in America speak American instead of English. A 'layshaft' here is an intermediate shaft in a gearbox. You only need a pulley on your generator sized to match rpms. The engine pulley will either be on the right or left depending on the way the Startomatic needs to rotate.

The Coventry Victor WD1 single cylinder diesel engine looks like a Lister. I couldn't tell for sure where the power take off on the Coventry is. There is a lever on one side that looks like it puts it in and out of gear. There is a flange next to that. Mount a pulley there.

[joestue]

Flux could probably tell you better but it should be as simple as reversing the brushes.. also note that sometimes the brush holders aren't designed to hold the brush properly for reverse rotation, so if the brushes make noise when spinning backwards they may wear very quickly.

reversing the brushes should preserve the residual field, and depending on how they compound wind the machine you may need to reverse the polarity of the compound winding.. you'll need a variable load for both the dc output and the ac output to verify this.

I had an old generator from a '76 motor home and the ac was picked off the rotor through slip rings, the dc field supply and 14v battery charging output was picked off the rotor via a dc commutator. --they did not share the same winding. the dc field was sent through the dc field coils for a shunt winding.. the ac output was compounded by sending the ac output current through a separate coil wound around the outside of the field coils--it is this coil that may need to be reversed as well to preserve output regulation.

alternatively you can reverse just the polarity of the dc field coils. --this will reset the residual magnetic field to the opposite polarity.

[Ianhw77k]

dnix71, sorry about the language barrier we also refer to the gearbox part as a layshaft over here. What I'm talking about is a sort of idler shaft, between the engine and the generator, supported by a couple of bearings with a pulley on each end. The engine belted to one end and the other end driving the generator. Anyway, it seems you know what I mean. As for the Coventry Victor, there is only one place to take the power from and that is the flywheel, it only has one flywheel, unlike the old Lister CS which has one on both sides.
I'm all for keeping things simple so having an idler shaft between the engine, to me, just seems like more moving parts and more bearings to go wrong, that is why I want to know if I can change the direction of this generator/starter/dynamo.

joestue, that sounds promising, the only worrying thing is that when turned in the wrong direction, the brushes do make a chattering noise. It looks like I will have to do some more investigation and have a closer look at the brushes and holders. The rest of your reply does skim over the top of my head somewhat but I am getting better at this. I will discuss your comment with my brother (the brains behind the outfit ) and see what he thinks. It just so happens that he is picking up a very similar generator this weekend which I think rotates in the other direction, so maybe we can get a few ideas from that.

Thanks again for all the replies

[Flux]

Yes you can reverse it, but it is not going to be easy. As you say the alternator part doesn't mind. The dc end is a different matter.

Without all the details of the machine I assume it is a cross field regulated device.  You can reverse a plain shunt dynamo by swapping the field leads, but this is not a simple shunt machine. If you check I expect you will find 4 big brushes and 4 small ones at 45 degrees if it is a 4 pole (1500 rpm machine).  This brush position is critical and you need to mirror image it to reverse it. I think this is a big undertaking and I suggest you stick to a mechanical method of driving it in its design direction.

If this has been messed with you will have enough problems to contend with without attempting to reverse its direction. Unless main axis brushes and cross field axis brushes can be moved independently you will not get the required brush positions anyway

Flux.

[Ianhw77k]

Yes, it is a 1500rpm machine. Sounds like far more trouble than it is worth so I'll stick to a mechanical solution if that is the case. Many thanks Flux.

Ian

[dnix71]

There is a very nice set of color pictures of a WD1.

http://www.stationaryengineforum.net/t6516-coventry-victor-diesel



If there are holes in the flywheel for pulling it, then it should be possible to mount a plate using those holes and then mount a pulley on the plate. No new holes need to be drilled.

[Ianhw77k]

Again, you found pictures of my machine . She's in a bit of a more disassembled state right now, the injector pump needs re-calibrating, possibly a new injector and a new set of piston rings (the compression seems a bit low). As you say, there are holes for some sort of pulley mounting but I'll have to get some help from a local engineer to make me something, I don't have a lathe or milling machine. I plan to mount it all on a metal bed made up from heavy duty angle iron with some cast iron wheels. The generator probably weighs over twice what the engine does so this is going to be quite a heavy lump. I think I'll keep the starting batteries separate. Also, I plan to use radiator cooling on the engine so I will have to factor in a pulley for the fan as well.

If plan A fails, I do have a couple more, lighter generators to try but I like the idea of the Startomatic taking the strain of the starting for me. These engines can require quite a lot of cranking on a cold day, from what I've heard.

[dnix71]

I saw the comments and pictures about the valve seats. The proper fix is machined inserts. The valve stems and inserts should be of a material that is compatable. You can get a bunch of inserts made and when it's time for a valve job, just swap seats.

Some older plumbing in the US is made that way. Back in the day things were not disposable, they were made to be repaired.

The plumbing seat had a hex wrench socket broached below the seat and the seat and head were threaded to match. Stick an "Allen wrench" in the seat and unscrew it, screw in a another.

If the engines are difficult to start then the compression is too low. A good machinist can advise of the safest way to raise the compression some. Or tap and thread and install a diesel glow plug in the head.

My parents lived on a converted Japanese trawler for many years. The generator was powered by a Lehman diesel that would cold start without glow plugs because the compression was high enough.

[equiluxe]

You could reverse the diesel engine. Fairly easy on Listers and Petters I am not familiar the Coventry Victor WD1 although I did have a flat twin by Coventry victor which came unused from a MOD auction I used that on a generator set but with a Markon brushless unit, otherwise you could mount the two units in line with a flexible coupling or one unit higher than the other. I have done that in the past using a cogged or toothed belt as the distance was so small, worked very well, I have a photo somewhere which I will dig out and scan. If that is the alternator in the photo you have that can be reversed as the brushes are fully adjustable for both rake and position.Some where I also have a manual for that unit.