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View Full Version : Bottle jack with pressure guage port in the UK?



Inquisitor
27-11-2012, 11:21 AM
Does any one know where I could get a bottle jack with a pressure gauge port in the UK? I been searching for ages and can only find them available in the US, with a £70 delivery from one place!

4 ton would be ideal, 8 ton would do at a push.

martin54
27-11-2012, 12:05 PM
Depends what your intended use is so difficult to point you in one direction but you just need to alter your search a bit. I found a few under hydraulic ram but you could also try actuator.

kingcreaky
27-11-2012, 01:31 PM
Tangye Superline Bottle Jacks (http://www.tidyco.co.uk/store/tangye/jacks/tangye_superline_bottle_jacks_info.asp)

"Base fitted for optional gauge and accessories"

Still quite expensive!.

However; Ive got a normal bottle jack at home... it has a screw is 'release' valve... similar to a trolley jack... (you turn it when you want it to go down).

well; just an idea... could you not fit a guage to that port? perhaps even engineer a t-peace to maintain the release functionality at the same time?

Inquisitor
27-11-2012, 01:53 PM
Thanks Martin, I tried that and many other variations without luck. (I really want to avoid putting together a hydraulic system because it's too expensive and I don't know how ;-))

These are the sort of things I'm after:
http://www.jackxchange.com/images/pdf/345.pdf

I didn't really want to say what I want if for because it'll probably generate a lot of negativity but I'm trying to build a press on the cheap for laminating that I can monitor with an electronic sensor.

It's really frustrating to know that the ideal thing is available for under $50 but I can't hold of one for under £180!


Kingcreaky, thanks for the link :-) One extra option.

I have been wondering about the release port, but surely its an indirect link otherwise wouldn't it leak? My mechanical knowledge is not good :-)

kingcreaky
27-11-2012, 02:10 PM
if you unscrew this valve altogether it does leak!. im pretty sure it would work. il try in tonight i think ive got a valve

martin54
27-11-2012, 02:51 PM
a bottle jack is hydraulic so you are already playing about with hydraulics lol
Take it you don't need a lot of control over the pressure you require, be very difficult to get any sort of accuracy with something like that. Is it just a case of squeezing it together under pressure?

Inquisitor
27-11-2012, 03:24 PM
Kingcreaky, thanks for the help and the PM!

Martin, I know it's hydraulic but since it's all contained in one unit I don't have to work out what to get in the way of pumps, hoses etc :-) To be honest I don't know how much control is necessary to get perfect results but I'm sure that I can get useable results from quite a wide range, I've seen what I want to do done with a sublimation clamp even though the proper pressure is far higher. At any rate I'm generally pretty good at teasing out more performance from something than it's intended to give and if it doesn't work out then I end up with a very useful bit of kit anyway :-)

BTW, the problem may be solved! :-)

birchy
15-12-2012, 08:21 PM
You could probably use a load cell or strain gauge to measure to the pressure. Then you wouldn't need a special jack. Maybe you can utilise something like this: http://www.amazon.co.uk/Lincos-Hydraulic-hand-pump-10t/dp/B009M3SDN2

Inquisitor
15-12-2012, 10:43 PM
Hi Birchy,

Thanks, for the suggestion and the link. I'm coming around to the idea that I'll have to use a system such as you suggest. It's just that (can we swear on here?) it annoys me greatly that every time I look at a project such as this there's something in the USA that's ideal for the job at a fraction of the price of a less suitable alternative that's all we can get here, assuming there is even an alternative available here at all.

:dispirited:

Anyway, what I'm doing is hooking up a transducer (with a home brew USB interface) into a hydraulic line and using it with a ram and pump that I've borrowed for now so that I can concentrate on the rest of the system. There's plenty of other things to deal with :-)

For the record here's what I've considered so far:

Using a bottle jack and tapping it myself, cheap if I manage it but time consuming and prone to failure (will I get a jack that will dismantle, will I damage while taking it apart, will I introduce a weak spot that will fail...).

Using a bottle jack and using an existing hole, e.g. the release valve or safety valve! I've found a source of bottle jacks that come with an internal diagram now so I know how they operate and what's inside. The release valve would require a bit of precession engineering I think. The safety valve, apart from the obvious drawback of the potential for serious injury, would probably require the jack to be taken apart anyway to clean it out after I'd finished tinkering.

Using a bottle jack with a load cell, easy but the cost is in the region of getting the pump, ram and transducer etc. and then there's the extra mechanics to take care of too. I have considered using a system of lever and cheaper load cells but it's too much hassle.

Using an air cushion (air cushion jack, inner tubes or self built cushion), not outside the realms of possibility but the accuracy would be bad and the precision may be inadequate too.

Using a pneumatic ram, can't get one that will do the job directly for less than the cost the whole hydraulic system put together. I have considered using a smaller ram and a system of levers but there is too much to go wrong.

Using small load cells on my pressing plates, possibly a good solution but I'd need to experiment with a system that applies a known amount of force to get it calibrated which takes me back to step one :-)


If I get this thing working I intend to share the details so that others can benefit from it too, for that reason I want to keep the built as simple and cheap as possible (the bias being towards simple in the case of conflict).

m_c
15-12-2012, 10:57 PM
Figure out where the high pressure part of the jack is, and drill and tap for G1/8?

Inquisitor
15-12-2012, 11:22 PM
That's probably what I'll try ultimately :-) There are guides on how to do it online, I just would have preferred a commercially available solution for simplicity.

In any case I'm now in a position to experiment and test the viability of the project. If it turns out well then even the cost of a hydraulic pump and ram would be well worth it (8 uses would recoup the cost!).
If anyone is interested the diagram I found is here:
http://www.free-instruction-manuals.com/pdf/p47111365.pdf
That safety valve does look tempting :-)

D.C.
17-12-2012, 08:53 PM
Do you actually need to measure directly the pressure inside of the bottle jack or do you need to measure the pressure it is exerting on the work piece or the the gap between the head of the bottle jack and what you are forcing it against?
A pressure pad or similar on the external plate could measure that, or a linear encoder depending on what you really want to measure and bottle jacks van be gotten quite cheaply from xtools.co.uk

Inquisitor
31-12-2012, 06:50 PM
D.C., Thanks for the help and sorry for the delay in replying, I've been busy and ill :-)

I actually want to obtain the force, in PSI, applied to a board between two plates pressed together by the jack.

Normally the way this is done is by obtaining the pressure exerted on the ram and calculating the force on the board from the CSAs of the ram and board (and possibly return spring but I don't know if this will be significant until I experiment a bit).
There are several ways of doing it, but I was hoping to keep the ram/pressure sensor part under £70 because I know that this should be achievable (i.e. I can get a sensor for £25 and I know there are jacks with ports out there for around £30 quid I just can't get them to me for less than £70 :-) but there's always the DIY tap option so the < £70 is still viable).

BTW, I'm 90% sure that someone here has found me a hydraulic press with gauge tap for about the price I was hoping for :-)

Anyway, I hope everyone had a Merry Christmas and I wish you all Great New Year!