Right off of a low end panel saw, sweet & simple!

http://industrialbalancer.com/ - that looks about right!

That looks like it contains a "constant force spring" that I referenced in an earlier post. I think this is an excellent solution, but my concern was that the springs I found were only good for 25,000 or 50,000 cycles. That doesn't sound like a lot of cycles if you're doing a lot of 3D work (complex contour). For stepping to various depths and holding there, it's probably more than enough duty cycles.

Kevin,
The balancer I purchased doesn't dictate the cycle use...But, they are cheap enough. Around 50 dollars direct from the manufacturer. The McMaster Carr version is about 85-100 dollars.

And yes, I confirmed the idea when Leko and I were walking past the Panel Saw in our shop last week.

another idea.
 

The Pullman Industrial Balancer is a very interesting thing indeed! It's compact. If it can withstand lots of cycles it might be a great solution.

Here is another idea for a counter balancing method... might be fiddly but just an idea...

Have you guys seen the typical "roller garage door" mechanism?

As the Garage door rolls up and becomes a big wide coil, to help this event, there is a counter-balancing spring that sits on a shaft with 2 pulleys in each end with steel cables attached to them and to the bottom ends of the Roller Door.

As the roller Door goes towards the floor (to close) the spring gets tighten and counter balances the weight of the Door.

I don't know what the name of that type of spring is... it's physical shape is helical and the action done to it is a rotational movement. The spring is vested in the shaft, 1 end is fixed stationary and the other end is fixed to the rotational shaft.

THE END.
-------------

There is always room for confusion in explaining a mechanism with words... But I think most guys have seen a Roller Door.

Francis

Francis, see the last sentence & link in post #28 above - that's where I tried to mention the garage door type spring/cable/pulley system.

Quick update.
That spring balancer is doing just fine. 60 days of work, and not a hiccup.
...though, I think it could use a squirt of oil!

Sean,
Maybe you could post some pics of the new balancer on your build thread to update it? :)

Ask and you shall see.
Here ya go.
Sean
Attachment 4795

Attachment 4796

Thanks Sean,
That balancer looks very interesting. Keep us updated as your usage of it increases, and if you have any problems. :)
I was just wondering on your opinion of how this was working for you compared to the gas spring solution.
If you could use the balancer or a gas spring for a particular application, which one would you choose now that you have used both?

Just depends.
The Spring balancer works very well and you can really tune the coil spring to match your load. Down side is it takes up a good deal of room and kills the area in the car for the dust collection. But you can make it work for dustcollection by putting in some elbows or flexpipe to go around the balancer.

Gas strut is just simple - really cheap and elegant.

Gas strut is the way to go unless you need some really long extension stroke.

Gas strut - 20 dollars
spring balancer - 80 dollars.

gass spring??
 

Don't these things tend to push or to push down the spindle, not a lifting motion???
MAC

The gas spring naturally wants to extend/lengthen itself. The top of the spring is connected to the z-axis/spindle. The bottom of the spring is anchored/static.

gass spring??
 

YES YES I was looking right it and it didn't sink in the brain fast enough!!

thank you

Mac

Would this not work??

http://www.mcmaster.com/#9432k64/=5sbzb1

That is far too short for the z-axis.

Hi Guys,

I have weighed my Spindle and ally spindle mount which weighed in at
4.737Kg's. I then weighed the machined tool steel spider slide plate with 50x25x3 RHS, rack & Gas strut bracket as well as 4 x bolts, 2 being for the Z stops and 2 for the bracket, weighing 4.668Kg's giving a total of 9.405Kg's.

What I could not weigh was the quick release Steel mounting plate if we use it, as I do not have it yet.
We will also be adding a little more weight with regards to the spindle wiring + spindle cooling + Z axis E-Chain and dust collection, I'm wondering if I should round it up too say 12 Kg's and would this be enough or too much? Would it be too much to also allow for upgrade further down the track for a larger spindle ? or would that exert to much force back onto the motor ? I'm also trying to get my head around what length the gas strut needs to be, to provide maximum travel up and down to suit the 250mm Z axis or is it just a case of measuring the the max and min travel between the tabs?

Any help appreciated!!
Cheers
Tony.

Struts
 

I will be designing for a 250mm Z-Axis and therefore will be requesting a 250mm Stroke gas strut rated at 15kgs to be on the safe side as per the MM plans. The gassing of these struts to my knowledge is not an exact science so anything in and around 15kgs of force will do.

The issue i am finding is good old Australia is not making these things cheap and it seems that it will cost me around $ 40.00 for one unless someone can give me a heads up on a cheaper alternative.

no gas-spring needed with something like this:D

:eek:

Could be used to soften a piece of tough steak :D

How much more expensive is that???????:rolleyes::eek:

poor roller bearings :)

CNC Oil Rig!

Hi All,

Just for the record, very little MM use over the last 5-6 years but my gas strut failed just the other day by leaking some oil out onto the job I was cutting. Once the file had run and I parked the machine and turned off the power the spindle slowly dropped to the table.
Not a bad lifespan me thinks :-) off to get a new one in the morning.

Cheers
Tony