MechMate CNC Router Forum

Go Back   MechMate CNC Router Forum > Structure & Mechanics > 40. Z-Slide
Register Options Profile Last 1 | 3 | 7 Days Search Today's Posts Mark Forums Read

Reply
 
Thread Tools
  #1  
Old Mon 08 February 2010, 22:54
liaoh75
Just call me: David
 
Taibao
Taiwan
Gas Spring Failure - was upside down

Has anyone ever had a gas spring fail? I was cutting away yesterday just like any other day. At the end of the day, I turned off the power to the beast and the spindle dropped to the spoil board. Puzzled, I released the tensioning spring for the stepper motor and to my surprise, there was no pressure in my gas spring bought from McMaster two years ago. Do these things have a rated life span? I remember reading about this before somewhere in the forum and it was mentioned at the time that this has never happened to anyone. Well, now it has.

Thats not the main problem. The problem is, McMasters will not sell to me any more as I'm ordering from Taiwan. Can anyone help me source this thing?
Reply With Quote
  #2  
Old Mon 08 February 2010, 23:05
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Which way around was your spring installed? Thin rod to the top, or fat body to the top?

We replaced our first spring after about 3 years because it felt "soft" (fat body to top).
Reply With Quote
  #3  
Old Tue 09 February 2010, 00:15
KenC
Just call me: Ken
 
Klang
Malaysia
2 years sounds long enough
But feels great if we can change it after 3 year because it feels soft

I don't remember reading the type of the gas spring rod end. Should I look for straight threaded rod end or ball joint ends?
Reply With Quote
  #4  
Old Tue 09 February 2010, 00:44
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Only use the straight threads, and don't tighten the nuts . . . this can also cause seal wear if the mounting points are skew.

David, you are probably going to have to walk around motor car spares shops with a sample in your hand.

Is there anyone who can offer to ship a McMaster spring out to David? (David, what is your part number?)
Reply With Quote
  #5  
Old Tue 09 February 2010, 01:14
KenC
Just call me: Ken
 
Klang
Malaysia
David,
I yet to purchase my gas spring, have my eye on this They come in a pair, Since Taiwan isn't that far from Malaysia, do you wanna share the pair?
Reply With Quote
  #6  
Old Tue 09 February 2010, 01:23
liaoh75
Just call me: David
 
Taibao
Taiwan
I'll check that part number ASAP. I'm not at the shop now.

Is there any danger to running the beast without a working gas spring in the short term?
Reply With Quote
  #7  
Old Tue 09 February 2010, 02:15
sailfl
Just call me: Nils #12
 
Winter Park, FL
United States of America
David

Looks like you might be able to pick up a gas spring from the source that Ken has supplied. There must be other countries that sell gas springs. Last resort, I will help you.

I think that the 2 years seems like a short life span for some thing like a gas spring.
Reply With Quote
  #8  
Old Tue 09 February 2010, 02:30
KenC
Just call me: Ken
 
Klang
Malaysia
Some how gas spring are not common off the shelf but they are used everywhere in our life! lets start with car hood gas lift, then booth gas lift, auto doors, ... etc etc...

After some serious leg work, I found more then a few sources here but most don't have the complete specs & one custom gas spring shop. RS is the only one that provide adjustable gas spring & has the complete specs. AND its the most expensive, but RM50 difference a piece is bearable consider the adjustable feature a good addition.
Reply With Quote
  #9  
Old Tue 09 February 2010, 04:53
normand blais
Just call me: Normand
 
montreal
Canada
http://mechmate.com/forums/showthread.php?t=591 A different approch around post 21
Reply With Quote
  #10  
Old Wed 10 February 2010, 08:32
liaoh75
Just call me: David
 
Taibao
Taiwan
Ken, I don't think that spring will work with my 350mm extended Z-slide. Very interesting that that particular gas spring is adjustable. (only once though)

Nills, thank you for offering to help me. I may end up taking you up on that offer. I will be in the shop tomorrow to get that part number. My other business has me all tied up at the moment.

Normand, I like that approach, but I'm a little nervous about playing around with something under that much pressure.

Gerald, my gas spring is mounted fat side down. Is there a reason you ask? After you ask that question, that got me thinking about why my gas spring failed. I am assume the advantage to mounting fat side up would be that no dust gets into the seal? Also, I don't have any nuts on the thin side. (No pun intended)

Last edited by liaoh75; Wed 10 February 2010 at 08:35..
Reply With Quote
  #11  
Old Wed 10 February 2010, 08:52
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
David, quite a serious mistake to mount "fat side down", sorry that you did not see the discussion about this earlier;

A gas spring is destroyed by the gas leaking past the single seal in the whole system. That seal is at the neck, where the rod comes out of the body. (there is no seal on the "piston"). The body contains a little oil to keep the seal wet and lubricate the rod. If the fat side is down, the oil runs away from the seal and it dries out. Fat side up and the oil lies permanently against the seal. (Have a look at new hatchback cars, when the hatch is closed - when DIY guys replace the springs, they often go in the wrong way around)
Reply With Quote
  #12  
Old Wed 10 February 2010, 09:00
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
See discussion here (I thought this discussion was in a much more prominent place??)
Reply With Quote
  #13  
Old Wed 10 February 2010, 10:00
liaoh75
Just call me: David
 
Taibao
Taiwan
Ok Gerald, I got it now. Thanks for the info. As the gas spring itself isn't really an expensive part to replace, I'm ok with it, but I'm glad I didn't just replace it and move on. We live and we learn. I now remember reading about it before but, I guess it must have slipped my mind. You not only informed me about the mistake but took the time to explain why. Thank you
Reply With Quote
Reply

Register Options Profile Last 1 | 3 | 7 Days Search Today's Posts Mark Forums Read

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Gas Spring for 350mm YRD 40. Z-Slide 6 Thu 28 October 2010 04:49
Customized Gas Spring KenC 40. Z-Slide 7 Fri 07 August 2009 22:42
Modifying a gas spring to make it pump-able hans.arnell 40. Z-Slide 8 Sun 04 January 2009 07:51
Gas Spring : Compatible automotive gas spring Nikonauts 40. Z-Slide 0 Sat 03 January 2009 09:59
Mamba 6-Roller Z Slide with a gas spring not fully retracting...due to build mistakes dmoore Archives 8 Thu 05 June 2008 14:38


All times are GMT -6. The time now is 08:11.


Powered by vBulletin® Version 3.8.3
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.