Gas Spring Specs

[Chrisjh]

Hi All,

Does anyone know the thrust of the gas spring fitted to the factory converted Syil X3 Mills?

I am going to replace mine with a gas spring with 300mm stroke (current one has 200mm stroke which limits the upper movement of the head). I need more Z headroom as I use a 5" milling vice fitted more or less permanently to the table. The vice robs me of a considerable amount of Z headroom.

I guess what I need to know is the weight of the head assembly so that I can select a new gas spring with the correct thrust. I have checked the existing gas spring identifier but it is written in Chinese. Unfortunately I can't read Chinese unlike our new Prime Minister.

Regards

Chrisjh

[rad45]

Hi Chris,
I did the same thing a few months ago. But what I did was to put two gas struts on the machine. One on each side to balance the load. I worked on the basis that the head assembly wieghs in at about 25 kg which means that there will still be a little load taken by your Z ballscrew. I don't think you want the head to be floating on the struts, but rather the struts take most of the load but the load on the ballscrew is still always positive.
Regards,
Russell in Perth, Western Australia

[LeeWay]

I used a 30 pound model on my mill. I think my head may weigh around 70 to 75 or so max. My thought is if you equal the exact weight of the head, then you are having to push the Z too hard on the down stroke. The purpose of the gas spring is to keep the head from spinning down when power is cut and to releive some of the pressure off raising the Z. I think there is probably a pretty wide range of acceptable strengths. Probably anywhere within 30% of the head weight to maybe 65 or 70 %.
I'm not an engineer and have no stats or formulas, so take this advice at face value.

[neilw20]

I just had a new strut for au$30 off the shelf.
816mm long, which is heaps longer than the original, of 588mm.
Struts Australia model K816-22-365
I am putting a long spacer to extend the upper attach point way up, and still close to the head in the same place as before.
Someone else has posted a weight of 45KG on the Super X3.
I believe this, as I had the original strut tested today and found it was 60KG.
When I put it back on rapiding down I could get it skip steps. Going up was OK.
I have gained 134mm travel. 83mm at the top, and 51 at the bottom. I have added an extra interrupter strip 83mm further up and left the orginal home one in place.
Now when I reference, I don't have to us the new upper limit unless I need more headroom, so referencing time is still the same.
When I need more headroom I turn off softlimits temporarily, move up 5mm and reference Z again to use to top stop. How do I turn on soft reference using VB in the reference cycle?
Rotated head should be more useful near the table now.
I had the new strut charged to 45KG and I think this is a good compromise.
That should be about 55KG fully compressed.
Hard to get the gas out, but easy to put more in.
Now mounted the correct way with the skinny part DOWN, so it shouldn't leak away slowly because the seal is now covered with oil.
What am I going to do with the old 60KG strut with a 231mm travel and Chinese balls?

[jjvogre@aol.com]

hey,

if you need a spring lmk. thats what I do, do you know what size wire it is (.187", etc.)?

I also have spring testers to see the load @ a certain height.

.02,
jdog