First failure

[kevsRV1S]

Hi guys. We have had our RV1s for years with no problem until now. The vacuum pump cuts out every now and again. Any ideas what to check and where to look for the problem?

Thanks

Kev

[Gopher]

I'd take a look at the pump itself. Remove it from the arm, test it on the bench, perhaps take apart the assembly on the end and clean it - it could be full of years of crap. Check bushes/contacts if you are feeling sufficiently adventurous to strip the whole thing. Of course the pump gets a lot of work so it could be on its way out. The exact model replacement can be quite expensive, I had a pm recentlyish from "fredob" asking what we paid for ours back in 2011. It could be worthwhile asking him if he went on to purchase a new one and what it came to this time. (I'd guess somewhere in the £200-£350 range)
IIRC the pump is switched by the relay on the arm board - but I could be mistaken. Phonoplug makes replacement arm boards so would know exactly where the loom goes if you wanted to buzz out the loom.

[kevsRV1S]

Hi Gopher. I have checked the pump on the bench with a power supply and it seems to be ok. I have also checked the wiring . I guess I will need a comms  board.

[Mike]

ISTR the pump is switched by a relay on the arm board - could be failing contacts on that.
Sparkfun sell a small vacuum pump - not sure if it would fit in the arm, but you could mount remotely.

[kevsRV1S]

That reminds me, I have changed the relays on the arm board but am still getting a failure of the vacuum.

Thanks

kev

[kevsRV1S]

Are there any sellers of parts for  the Rv? I appreciate that it is an old machine but am hopeful that there are parts out there in somebody's garage/shed

Thanks

kev

[spiyda]

I'd make doubly sure its not the motor by adding say a 12V piezo buzzer in parallel with the motor
then you will hear the buzzer cut out if it is a supply problem.
It sounds a bit primitive, but it is actually not a half bad way to fault find, your ears will hear a change in tone better than see an LED or meter.
(I have an FET driving a battery powered buzzer for lower power circuits, but a plain old buzzer will be fine in this case as there is plenty of current floating about, you can put some series resistance and it will still work if you want to limit the current)
you should be able to do the same in parallel with the relay coil..  they don't draw much power.

I looked at this as a possible replacement, but I haven't actually tried it..
http://www.ebay.co.uk/itm/161081748554?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

It might be worth one of us getting one to see if it will do the job for future reference

[Jason]

One of the main parameters will be the ability to work at a high duty cycle
with "stalled air". Many pumps use the airflow to cool themselves and if
they aren't passing air then they will overheat.
I don't have a suggestion for a suitable pump tho, sorry.

[SkyWalker]

The original pump is still available from these guys:

Gardner Denver Thomas GmbH

Part No: 50200   G 12/045

I purchased one just this last month, cost £150.  Expensive for what it is but worth the money if you want to keep to the original parts. Arrived within a few days, fitted and now working a treat!

If you Google Gardner Thomas they are on the web.

[Mike]

As & when the pump on mine dies I'll probably replace it with something mounted off the arm, in a soundproof box, as the pump noise is quite annoying.   

[kevsRV1S]

Thanks for all the help so far guys, much appreciated.

[Mike]

I looked at this as a possible replacement, but I haven't actually tried it..
http://www.ebay.co.uk/itm/161081748554?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

It might be worth one of us getting one to see if it will do the job for future reference

I just ordered one to have a look at

Many pumps use the airflow to cool themselves and if they aren't passing air then they will overheat.

This won't be an issue with diaphragm pumps, though mechanical ruggedness and motor design duty cycle could still be an issue.

[Jason]

For reference the GD-T URL to the part is:
http://www.gd-thomas.com/templates/pages/product.aspx?id=2464