Funicular railway - further help needed

[oliverhanmer]

Hi All. So you may remember the long story of getting my funicular railway fixed. Here's the link to the original thread if anyone is interested. http://www.pistonheads.com/gassing/topic.asp?h=14&...

It was a resounding success at the time and we've had a few months of it working. We now have a problem with the funicular and I'm returning therefore to piston heads for advice. The two original PHers who helped so much with it are swamped with work so I'm after a bit more guidance. I posted the text below in the original thread but conscious it's a bit old I thought I'd start a new one.

The motor is the problem. It's a single phase brake motor which has a gearbox attached to drive the cogs that move the chain and therefore the carriage up and down the track. The motor has two capacitors both of which have blown. They were run capacitors with 16uf and 40uf ratings. I've replaced them and it worked for a bit - although it needed a push to get it going if it had any weight in it- but it's now stopped working altogether. The motor hums but just won't start. I've wondered whether I need a start capacitor and a run capacitor rathern than two runs but I'm not sure if that would help or what rating I should get.

I'm increasingly coming to the view that a new motor and gearbox is the best option. It would require a bit of engineering to get the shaft holding the chain cogs attached to the gearbox but I've assumed that's not too tricky - correct me if I'm wrong.... The motor just seems a bit unreliable - you might remember it was the original one that I had rewound - and given that it's what does the leg work I need something I can rely upon. I'm not sure if I need another brake motor - I'm told they are rare in single phase and expensive, or whether I can get away with a standard one and rely on the tension in the chain to hold the carriage in place. It sits quite happily in the middle of the slope without the motor working. I think I would need a motor and gearbox as the current system has a bespoke fitting on the shaft connecting the motor to the inner workings of the gearbox.

A motor seller I spoke to said something about checking the power supply to the motor because if that's dropping when the motor starts it often can cause the humming but not starting symptoms I've mentioned. I've not done that - not sure I know how - but does that sound like that could be the cause of the problem?

A response on the original thread, for which thanks, suggested the starting switch might have gone. Is that an easy fix?

I'd be grateful for any advice/thoughts. Having had it working we (and tescos delivery men) really miss it!

Let me know if you need any more info/pictures etc.

[oliverhanmer]

Thanks for the responses. My sense is that the first thing to do is to establish how 'banjoed' the motor is by getting a company like the one suggested to have a look and to advise on cost. I'd prefer to keep it simple and a converter and new three phase motor, whilst attractive, seems more complicated given that I'm not hugely skilled in this kind of thing.

I can ask the motor company to repair it and add a fan, deal with the capacitor issue etc if it is economical to do so rather than start from scratch with a new motor.

Does that sound a sensible way forward?

Thanks again for all the advice.

[oliverhanmer]

This is hugely helpful. Thanks everyone. My inclination always is for DIY because I enjoy the challenge but I'm nervous of electrical stuff so I think I'll need expert input.

How do I know what horse power I need for the motor? We made a frame and box and it's fairly heavy. It's hard to know what was there before because it was completely derelict when we moved in. I think though it was much smaller and therefore lighter than what's there now.

If I accept that the current motor is not worth repairing, I'm persuaded by the three phase idea with a converter. I'd definitely need an electrician to sort that out - what kind of electrician do I need? Does anyone know someone near Caterham in Surrey?

I'm not sure whether I buy a new one that is then engineered to fit my gearbox or whether I buy a motor and gearbox. I think the former seems better - the gearbox is in good order. The one linked to on eBay seemed to look right but I'd need to check measurements of connections to the gearbox etc. What else would I need to worry about?

As ever I'd be lost with piston heads so thanks again everyone for all the advice.

[oliverhanmer]

Thanks for the advice. The plate on the motor has the following information:

50hz
240V
5.1 AMPS
0.75KW
38.12/1 RATIO
IP 54
FIN 37 (then there is an RPM but no number)
BRAKE 240/1/50

In terms of frame size I assume you mean the standard dimensions of the motor so length of the motor, diameter of the flange, diameter of the pinion etc....

they are -

from one end of the shaft to the other - 36cm
motor length - 26cm
flange diameter - 12cm
shaft length from end of motor to end of gearbox pinion - 3cm
diameter of gearbox pinion - 3.5cm

is this what is needed? Let me know if you need anything else

the motor attaches with four bolts and metal rods directly to the gearbox, it is not mounted in any other way

I can send photos if that helps, the link to the other thread in my first message has a photo of the motor and the motor plate.

thanks again.

[oliverhanmer]

You've got to love a good flange. So what does all that mean for me? (Not the flange loving but the last post about motor size etc)

[oliverhanmer]

Ok further measurements.

6mm flange hole diameter
Holes 100mm apart on the diagonal and 70mm horizontal
100mm from centre of gearbox to frame for gearbox (which extends out to under the motor when connected)
Shaft diameter 13mm
Maximum motor size once connected 320mm (which is the maximum space with s bit of wriggle room between the motor and one of the chain cog axles)
Current shaft length from pinion to where the cooling fan was 360mm

I've given a few other measurements in an earlier post if anything is missing. If there is still stuff missing please let me know

Thanks for the advice it's much appreciated. I'll wait to hear views on what motor and inverter I need.

[oliverhanmer]

Thanks for the suggestions. The frame size is 80mm.

Current motor is 0.75kw. Would a 0.55kw have sufficient power to get a loaded cart up the slope? If there is a chance it won't then I need to get a more powerful motor.

What flange type am I looking for and what inverter would be suitable?

If you can help with these questions that would be great and I'll start looking in to possible motors etc

Thanks again.

[oliverhanmer]

Thanks. I've made some enquiries about the SEW motor and will see what they say. The inverter linked to seems expensive. Is that the price I'd need to pay I thought they were around £100-£150......