A picture in my album of assembly used. I think it balances about 15kg on a Sieg SX2P quite nicely, just very slight lift.

When i installed my wm18 mill i removed the gas strut and couldn’t begin to compress it

seems to work ok on the mill

sorry not much help as to what rating you need

That SGS link is useful, it is going into my favourites in the browser. The knee of the Tom Senior could do with a bit of assistance, especially when heavy kit is on the bed. I will be checking the dimensions and will have a look to see if they have a suitable strut.

The SGS site rates struts in Newtons, not newton metres.

Edited By old mart on 20/05/2020 18:19:28

The strut assembly fits to the top of the column with the struts down inside. A cable fitted to the head at one end goes round the pulleys and fitted to the underside of the plate. So the travel was halved meaning twice the load. This arrangement was because the column height didn’t allow enough length for the strut stroke and also gives a straight load on the strut. In all it has worked well.

Brian, the head of my drill weighed about 40kg, I first tried a 400n strut, but it was too strong, I then tried 350n strut, it was about right, but maybe still a little too strong, it's difficult too calculate exactly, if I was doing it again, I'd buy an adjustable gas strut, if my memory serves me right, they were 20 something quid, that way you can fine tune it.

The benefits of hindsight.

But like I say, don't worry too much about the initial compression, even really low weight rating struts can be difficult to compress without leverage.

Yes, sometimes! The figure is torque on the assumption the strut is for use in a known hinged arrangement like a car hatchback. I guess it's convenient buying spares for particular vehicles or something. But really they should be in Newtons. From this website:

Maths make my head hurt, but you're good at this stuff Duncan. Assuming the strut is vertical, and the head is 'x' kilograms, what formula would give the strut in Newtons?  (I think it's the above with d = 0)

Buying a strut for a mill, I would always go for one calibrated in Newtons rather than Nm, mainly because I don't have a feel for the difference! Working in kg for struts calibrated in N is inside my comfort zone and 1kg being close enough on earth o 10N for most practical purposes keeps the arithmetic simple. (And I need all the help I can get.)

Dave

Edited By SillyOldDuffer on 22/05/2020 10:36:19

I don't know where the 1.06 factor comes from, but otherwise the sum is correct. The cosine of the angle twixt strut and vertical (call it alpha) is (c/d)

the vertical force required is F*(L/d), and the vertical component of the cylinder force is F1*COS(alpha), so for equilibrium

F1*c/d = F*L/d.

multiply both sides by d/c gives F1 = F*L/c. Perhaps the 1.06 is to make it stay up, not be just in balance. If the strut is vertical, c = d.

Still doesn't involve Nm, which may well have been an imsprint