GRP PETP double bearings type 6S000

TWIN-PETP roller bearings type 6S000

The table below shows all key dimensions of the 6S000 series TWIN-PETP roller bearings in GRP tube. The measurement D is the outside diameter of the GRP tube.
Click on the pictures for a detailed view.

PART NO.	Bottom Bearing dia. "db"	Top Bearing dia. "dt"	TUBE dia. "D"	HEIGHT "H"^*2	WEIGHT^*1	WORKING LOAD (max)
6S030 - 6S049	30 to 49 mm	30 to 49 mm	90 mm	max. 800 mm	1.9 kg	1300-1800 kg
6S050 - 6S069	50 to 69 mm	50 to 69 mm	110 mm	max. 800 mm	3.1 kg	2500-3200 kg
6S070 - 6S089	70 to 89 mm	70 to 89 mm	130 mm	max. 800 mm	3.6 kg	4200-4800 kg
6S090 - 6S109	90 to 109 mm	90 to 109 mm	150 mm	max. 800 mm	4.5 kg	4900-6200 kg

*1: Weight taken with a 800 mm tube.
*2: Longer tubes are available at a surcharge.

The applications for the 6S000 series bearing:

The 6S000 series bearings are developed as a more affordable alternative on the 6D000 bearings. The bearing is made of PETP (also known as Arnite, Ertalyte, Sustodur & Ultradur) in a GRP tube, allowing it to be laminated directly into the hull. It's primarily meant to be used on tiller steered boats, but could be used on wheel steered boats if the tiller arm / quadrant is above the top bearing.

Installing the 6S000 bearing:

Installation of JEFA Marine composite bearings:

Secure the bearing-housing in it's place in the hull. The bearing should be jigged in place firmly so that it won't alter position when worked during lamination and remove the bearing ball to make sure no resin will enter the rollers.
Make sure the hole in the hull is a few millimetres bigger than the bearing outside diameter and tape close the gap at the bottom.
Cast some resin in the gap to close off the hull laminate .
Laminate the hull and bearing creating an outer skin. It can be tapered down beginning just above the self aligning bearing in the bearing tube.
On top of this outer skin there should be a foam ramp or fillet (minimum 200 kilo/m3 density), which encircles the bearing housing. Make a wooden circular tool to create a nice fillet.
Laminate the hull and bearing making sure that the laminate runs up the side of the bearing in full thickness. It can be tapered down over a 100 mm span beginning just above the self aligning bearing in the bearing tube.
There should always be a skin joint around the bearing that is at least three times the bearing housings measurement in diameter, and the laminate should have a minimum thickness of 1.5x(1.8+(LWL/1.8), this thickness is not including the foam ram mentioned bellow. (LWL in Meters).
In stead of using a filled around the first outer skin, one can also make a web of triangles which will be included in the final lamination (see model below).

Please remember that these guidelines represent good practice, however all structural components of a sailing vessel should be engineered by a qualified engineer for the actual case. JEFA MARINE takes no responsibility for any structural failures which might result from the use of these guidelines.

Installation example of the 6S000 bearing not using a fillet for stiffness but a web structure

6S000 specification form:

Please click the left icon to open the 6S000 specification form in Adobe PDF. You can fill in the gray field with the correct info and tick the appropriate boxes. This form is required to guarantee a correct production of your bearing.

6S000 examples:

Fitting tiller stops to the 6S000 bearings:
The 6S000 series bearings standard have no tiller stop arrangement . By adding a flange with stops which can be bolted to the deck, additional tiller stops can be added. There is one flange to work with our tiller heads Ø25 mm to Ø40 (6SP035STP) and one to work with our 50 mm tiller head (6SP050STP).

6SP035STP dimensions:

6SP050STP dimensions:

TILLER STOPS
PART NO.	DISCRIPTION	corresponding tiller heads
6SP035STP	Tiller stop up to 40 mm shaft	25 - 40 mm
6SP050STP	Tiller stop up to 50 mm shaft	50 mm