Boys toys

[joe90]

I don’t remember who was responsible but a car lift for the garage was mentioned on a thread and I can’t stop thinking of increasing my tool count, question for the boffins, how difficult/expensive is it to convert from three phase to single phase?.  There are several second hand two post lifts on 

Ebay fir a third of the price of a new one but they are all three phase.

[Tennentslager]

1 minute ago, joe90 said:

I can’t stop thinking of increasing my tool count

Steady now Joe

[joe90]

Just now, Tennentslager said:

Steady now Joe

 

I have a new large workshop with my new build, a classic kit car, a classic tractor (to cut the meadow, honest). And the wife’s ageing mx5. I really really fancy a two post lift as I am getting too old to lie on my back under a car on axle stands. If I tell SWMBO that i can service her car if I get one I won’t get grief “buying more tools”. Up till now I “need” these tools to build our new house!.i have found a new one for £1200 delivered and second hand 3 phase £380 plus delivery. 

[Onoff]

The BiL as I said before converted his three phase, 2 post Bradbury to single phase and it works a treat just by changing the motor. 

 

I think the original motor was 3HP. He faffed for several years with it on a 3 phase converter and geared it down via changing the pulley at the top. It'd put a Robin Reliant through the garage roof but stick a Granada Scorpio on it and it'd run out of steam about 4' off the deck.

 

I think the new single phase motor is 2HP.  All I did was make a dog rough up/down control box with a couple of buttons and contactors. 

 

I'll pop round one evening and see what's what in terms of original motor vs new motor and the top pulley ratios.

[PeterW]

You can get a 3 phase rotary converters but they aren’t cheap and they have their limits. As @Onoff says, swapping the motors is quicker and cheaper as you can pick up second hand 2 & 3hp single phase motors on eBay for not a lot. 

[Onoff]

I THINK it was a TEC motor but will confirm tomorrow. They really are pretty cheap.

 

https://www.ebay.co.uk/itm/TEC-Single-Phase-Electric-Motor-230V-50HZ-Foot-Flange-Face-CapCap-0-25-to-3-7KW/122080278808?

 

One thing is the motor output shaft diameter may be different to what's there at the moment. I honestly can't remember what he/we did but I did give him any random motor pullies I had to play with and he might have had to drill out and re-keyway one.

 

Single phase motors are naturally bigger than 3 phase ones for a given power but in this instance not really an issue. Loads of space atop the post. Might too have to make an adaptor plate - simples! Single phase motors are also more complicated in that amongst other things they'll have a couple of large capacitors that can die but are easily replaceable. Also a centrifugal switch possibly.

Edited December 11, 2018 by Onoff

[joe90]

Thanks guys for a prompt reply, (it’s a bit like Christmas ?)

[dpmiller]

One caveat on the single-phase motor- starting current is high and too much voltage drop can fry the motor so the rest of the garage wiring needs to be to-spec. A 3Hp motor will take between 10 and 13A full load but it's starting current could be double or even treble that.

[Onoff]

18 minutes ago, dpmiller said:

One caveat on the single-phase motor- starting current is high and too much voltage drop can fry the motor so the rest of the garage wiring needs to be to-spec. A 3Hp motor will take between 10 and 13A full load but it's starting current could be double or even treble that.

 

Yep, this runs off a plug top and the lights dim! I'll stick a clamp meter on it some time. 2.2kW motor rings a bell.

 

When it was on the 3P converter it was wired with 3-core & earth 6243Y