Adding rose joints to remove backlash play in the 26M steering.

I have always found the steering on our 26M Tarka a bit mushy with a definite lack of feedback from the rudders when sailing. At first I associated this with the need to remove too much feedback from the motor.

When sailing I usually disconnect the motor but this was difficult to do with the original fittings and even when detached there was still a lot of free play in the steering so I decided to look into the options. The first option was to go for a complete new hydraulic system but a bit of crawling round the aft berth and shaking the steering linkages confirmed that the real problem was all the free play in the rather complicated steering linkage. Therefore before deciding on splashing the cash on an expensive hydraulic system I decided to improve the existing system by removing all the free play. This was relatively easily achieved and not very expensive by replacing all the simple ‘bolt through a hole’ pivots with proper stainless steel rose joints similar to those that are still used on high performance car steering. The only real issue with this was that the existing parts had imperial sized 3/8” holes that are slightly smaller than the 10mm holes needed for the rose joint bolts. I also decided to make a new connecting bar between the rudders so that I could introduce some adjustment to the ends to make the steering symmetrical i.e. each rudder move the same amount. The link to the motor was also modified to include a rose joint at the motor end and make removal and reconnection easier when changing from motor to sail. Macgregor or rather blue water Yachts already offer a modified motor connector with a quick release connector but it’s rather expensive by the time postage and packing to the UK has been added. I therefore decided to make my own; this turned out to be a little more difficult than anticipated as although suitable quick release ball joints are readily available in metric sizes they are not available as far as I could see in stainless steel and I didn’t fancy needing to handle a zinc plated joint that would need to be greased to have any chance of remaining rust free. In the end I ended up with a modified version of the original that could both cope with the tilt of the motor as well as removing the backlash in the connections.

I have ended up with a much improved ‘feel’ when sailing without making the helm feel oversensitive to the motor. The rose joints have removed almost all the backlash in the system and significantly reduced the friction which although this had meant that there is now some torque steer from the motor when using higher power but its more than compensated for by the improved feel when sailing. There is still a slight amount of play due to the end of the Teleflex linkage swaged end being a bit loose on the cable but that’s minor and appears to be still secure and isn’t going to change.

A hydraulic ram conversion kit is available for the Mac’s but at £1000 it’s a bit expensive and I’m not convinced it’s an improvement as it is normally fitted with a non-return valve which effectively removes all feeling and feedback from the rudders and motor. If the valve is left out it’s not clear if this gives too much feedback when motoring – something to discuss at the boat show with the suppliers perhaps.

The changes included:

New rose jointed adjustable steering link between the two rudders, a rose joint connection to the outboard end of the linkage, a modified clevis pin connection to the motor steering arm to allow easy disconnection and reconnection of the motor. A thrust bearing in the motor steering arm to allow the linkage to accommodate the motor tilt.

All the parts were available in stainless steel from the internet and the only fabrication was the new steering arm and welding of the threaded connectors for the rose joints.

Total materials 4 rose joints, 2m stainless tube and 3 threaded connectors, I thrust washer, two clevis pins.

The new steering rod was fabricated from 2m of 22 x 2mm wall stainless tube this was heated with a blowlamp and bent to match the original than the ends cut to length and a slot sawn down the end to allow the threaded connectors to be inserted, crimped into place using a vice than welded (small mig welder and stainless wire used). The original steering bar could have been used but I wanted to keep this to check the geometry although this was actually unnecessary as there is plenty of clearance and the tolerance on length which can be correct with the adjustable ends. The only difficult bit turned out to be increasing the size of the holes in the short rudder steering arms whilst lying on the aft berth using a hand reamer to avoid the need to disassemble the steering arms off the rudder shafts.

The stainless 22mm dia tube was filled with kiln dried silver sand (from B&Q) and the ends sealed with wooden plugs. This is necessary so that when you heat the tube to bend it using a propane torch you don’t allow the tube to collapse. I heated the tube to red heat and held the end in a vice whilst bending it to match the original steering tube which was held next to it. Turned out to be quite easy and matched the original exactly. Warning – it takes a long time for the sand in the tube to cool down so don’t be too quick to empty it out. Any heat marking on the outside of the tube due was easily polished out with wire wool or fine wet and dry paper.

Steering linkage parts supplied by:

Rose joints 10mm 316 stainless steel

http://www.wdsltd.co.uk/product/5162/swivel-eye-rose-joint-rod-ends-with-male-thread-stainless-steel-din648-wds-852/

M10 threaded connector couplers

https://www.ebay.co.uk/itm/4-M10-A2-STAINLESS-THREADED-BAR-ROD-STUD-CONNECTOR-COUPLER-NUTS-FULL-THREAD/190543963941

Stainless tube:

https://www.metals4u.co.uk/stainless-steel/c8/tube/c85/25.4mm-od-x-1.5mm-304-satin-polished/p3040

25.4 mm x 1.5mm 2 meters Stainless 304 or 316

You need to make the new tube the same length between the end holes when the rose joints are threaded into the connectors as the original bar but the threads provide plenty of adjustment to make sure the rudders are parallel.

Before and after