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View Full Version : Your advice please on this Linear Rail system



Moondog
10-12-2004, 09:47 AM
Having ditched my IGUS rail system that I planned to use I am searching for a suitable linear system. THK rails are out of the question at around $8,000 for all 3 axis... ouch.... expensive over here...

There is a THK substitute that has all of the same specs etc as the THK from SBS Linear. the web page is

http://www.sbclinear.co.kr/english/product/product.htm

I have posted the page below as well.

Looks like an exact copy.. same load ratings and tolerances. price is about 60% of the THK or Star...

appreciate your advice on this....

Thanks in advance

cheers

svenakela
10-12-2004, 10:21 AM
Go for it! I have a similar source here in Sweden, they sell Korean produced guides, also about 40-50% compared to THK prices. They are awsome and take loads that we never will reach.

Cheers,
Sven

Chagrin
10-12-2004, 11:54 AM
Why did you ditch the IGUS products? Which IGUS product were you looking at, specifically?

Moondog
10-12-2004, 04:27 PM
Chargin...

i had planned to use and purchased the IGUS Linear T system. When I first enquired of the product they advised me (supplier) that I could use them in place of a THK style rail. I designed my machine (see project log) around this.

When I mounted the Y rails and attached the Z base plate there was too much friction. I ensured that everything was perfectly paralell etc. I phoned the technical people and they said that I needed to have my carriages (slides) much further apart.

My Z plate is 220mm wide which meant the bearings were 85mm apart which is fine for THK style of bearing. It would have meant that I needed to widen my Z plate which would have resulted in a reduced Y axis travel.

It appears that the IGUS system is fine if you strictly follow the design criteria.

If anyone is going to use the IGUS i recommend that they first get the technical people to do the calcs for you... they have very specific formulas for the distances and mounting options unlike the THK style.

Kookaburra
10-12-2004, 05:19 PM
Moondog,

Before you go too far you might want to check out the ISEL linear rail systems distributed in Australia by Applied Automation and Engineering in Notting Hill Melbourne. They are awesome quality and a great price as well. They have a huge range and some very nice low profile concepts and overall a great company to deal with. I don't think I can put their phone number up in this thread but if you PM me I will give it to you. If you look them up yourself and call them, ask for Kevin and tell him Dave from CNC Teknix sent you and he will look after you.

Moondog
10-12-2004, 06:16 PM
Thanks Dave.. I'll ring him today. In your opinion.. do you think the ISEL is better quality?...

I am using the ISEL Ball screw assy for my Z axis and I am very happy with that quality...

cheers

Kookaburra
10-12-2004, 08:10 PM
Moondog,

In my opinion, they are equal in quality to the major brand linear systems but much more cost effective. Good Luck!!

svenakela
10-13-2004, 02:42 AM
In a project we did we found the Igus-rails very suitable for the x-axis, but for the Z and Y-axis we found that the very small but still existing play between the guides was enough to give tolerance faults. They have only a couple of hundreds of mm (not noticable), but it became "amplified" when the Z-axis was in max position.
I have to add though that when the tool was maximum out the distance between the tool and the first rail was six times longer that between the rails...

Cheers,
Sven

Moondog
10-13-2004, 07:19 AM
svenakela..

My distances were not quite that much but at least 4 times. I was very dissapointed as i really like the IGUS concept. It may have been acceptable for my X Axis but I just lost faith in them.

I think if you designed a machine around the system and you undertook all of the required calcs for forces loads et.. it would probably be good. I am certainly not a mechanical engineer and I can't afford to pay a couple of thou for one either.

At least I know the THK style work. There are lots of examples here on the zone...

cheers

buscht
10-13-2004, 09:14 AM
Here is roughly what IGUS told me about their bearings. Use this as a rule of thumb.

Take the distance between two bearings on one rail. The rails cannot be more than twice that distance apart. Otherwise you will get too much binding.