MechMate CNC Router Forum

Go Back   MechMate CNC Router Forum > Structure & Mechanics > 50. Toolheads
Register Options Profile Last 1 | 3 | 7 Days Search Today's Posts Mark Forums Read

Reply
 
Thread Tools
  #31  
Old Wed 06 August 2008, 07:56
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
How can you say they will heat up if you don't know what speeds are being used? At what speed will a 6002 2RS C3 "heat up"?
Reply With Quote
  #32  
Old Wed 06 August 2008, 08:49
Port
Just call me: Port
 
Harare
Zimbabwe
the rubber seal is in contact and so friction results in heat. That is whyall spindles have some sort of Labyrinth seal setup
Reply With Quote
  #33  
Old Wed 06 August 2008, 09:42
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Then why do HSD use a sealed bearing at the top, and why do I have a sawdust problem with the Fimec spindle that has an extensive labyrinth seal setup and no seals? Please believe me that 6002 2RS C3 would be the most sensible choice in our case.
Reply With Quote
  #34  
Old Thu 07 August 2008, 04:24
Port
Just call me: Port
 
Harare
Zimbabwe
I am just giving you the theory behind the reasoning for the selection of bearings used in different applications. a 2RS will heat up more than a ZZ but the 2RS does give a better seal. That is why most high speed applications have bearings with out covers.
I have found the best type of seal for enviornments which are very dusty is a thing called a FEY ring.
Reply With Quote
  #35  
Old Thu 07 August 2008, 06:59
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
The last photo above shows "FEY" rings
Reply With Quote
  #36  
Old Thu 07 August 2008, 08:00
turnerseng
Just call me: andy
 
PMB
South Africa
Gerald, Port is right rather use an open bearing or ZZ the 2rs is a much tighter seal and will heat up. Thats if you are going to try and use a cheepie. As I say to my customers you get what you pay for.
Reply With Quote
  #37  
Old Thu 07 August 2008, 09:42
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Andy and Port, if I follow your logic, there is no application where a 2RS bearing should ever be used, and that they should stop the production of it. You are also saying that HSD, who produce fine spindles, are making a mistake when they use a small diameter 2RS bearing at the back end of their spindles.

You seem to be missing the fact that we talking of a 15mm ID bearing, which can easily handle 15 000 rpm in 2RS format, and that we very rarely run our spindles over 11 000 rpm. After seeing sawdust get past the "FEY" labyrinth rings and damaging the Fimec's open bearing, as well as having seen sawdust get past the Z shields of our stepper motors, as well as knowing our HSD spindles are trouble-free with 2RS bearings, I think I am making a pretty informed decision to use 2RS bearings at the small back end.

The big front end is another matter entirely. That bearing is 35mm ID and a contacting seal (2RS) will be no good at 11 000rpm.

I think you guys are generalising too much, and not considering the diameters and speeds of rotation.
Reply With Quote
  #38  
Old Thu 07 August 2008, 11:17
turnerseng
Just call me: andy
 
PMB
South Africa
Point taken on the id but I always stick to the basics like you do when doing wiring. If you have poor extraction dust will get anywhere not evenn the man upstairs can stop that. The fact is that a 2rs will generate more heat than a zz, heat causes bearing failure so asto at what RPM this failure is going to take place who knows, but we do know that the spindle will get hotter with the 2rs, fact.
Maybe the manufacturer hald less comebacks with the better sealing of the 2rs than the zz.
Reply With Quote
  #39  
Old Thu 07 August 2008, 11:19
turnerseng
Just call me: andy
 
PMB
South Africa
Gerald I always put a little grease on the fey rings stops more dirt and runs better on start up.
Reply With Quote
  #40  
Old Mon 03 August 2009, 01:14
rhfurniture
Just call me: ralph
 
Cheltenham
United Kingdom
Gerald,
How much life did you get from the cheapo bearings?
Also, the top bearing, is it just a standard bearing? My supplier lists ceramic skf's at this size, or would replacing with a P4 bearing be a good idea?

Just curious,

R
Reply With Quote
  #41  
Old Mon 03 August 2009, 04:46
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
The repaired spindle with the cheapo bearings hasn't seen any service yet.

The top Fimec bearing appeared to be a standard 6002.C3 (open, extra clearance). HSD said they use 6002.2RSL.C3 which also is a common standard bearing. Realise that these are small diameter, low load bearings, and thus I don't feel the need to go for expensive bearings there. (They are also easy to replace).
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


All times are GMT -6. The time now is 01:30.


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