Yes its me again
Last year I introduced you to the sliding MacRig
Well I have now taken it a stage further and introduced a sliding mast foot!
Oh dear I hear you all sigh, AndyT’s at it again! ~ Yes I am but hold on a minute, its not as daft as you might at first think!
K&S tube sell a very fine selection of telescoping aluminium and brass tube
I will let my photos tell the story, suffice it to say that it is infinitely variable, so sail tuning is a doddle ~ sit on the side of the lake and enjoy the warm summer water lapping over your legs while you sail your Footy back and forth.
This sliding mast arrangement I have tried in brass with the 4mm i/d mast tube silver soldered to the larger square section. I then sleeved this for the storm rig.
Yes it is a bit heavier. however the advantages it provides, I believe far outweigh the handicap.
I have not tried it in aluminium as I do not have the facilities to weld this. So as such whilst lighter I am unable to comment as to its performance.
Is the structural strength of the longitudinal square tubing great enough to support the lateral torsional forces exerted by the mast? One could, I suppose, include two laterally extended legs, which would slide fore and aft on two parallel flat plates, or on stiff steel wires, to take any excess force beyond that which the single central square tube would support.
The metal working and the brazing would be relatively simple, within the capability of anyone with a propane hand torch.
I have been using such square brass tubing to simplify the rudder post and tiller arrangements for my Glass Petrel boat, which has all-in-line tiller steering. The square rudder post rides within a circular section piece of tight fitting brass tubing, which in turn slides in the rudder post fixed bearing tube. Sounds complicated, but it allows a positive connection of tiller, soldered to a short length of square tubing, to rudder post that is easily disassembled, being held together only by a simple tapered pin (in clock-making style).
Fortunately the K&S round and square tubing sizes are all snugly sliding fits as you go up in size
After some quick photography, these photos show the construction and the installed tiller steering method. Forgive the untidy edges of the access hatch-I had to tear off the cover, which is glued on with something called “Zap-dap-a Goo II” which sticks quickly, stays flexible, and can be pried off readily. I also have used it for the main hatch and it seems waterproof.
The rudder shaft is round brass. The tiller is just one section of one of those little electrical wire connecting blocks with brass rod soldered to it as shown - the two screws are used to lock it to the shaft.
The HS55 servo arm has a length of brass rod bent as shown to run in the slot made in the tiller. The loop around the central fixing screw is just to supply some twisting resistance. The red tape is only temporary :lol:
The idea was to get the rudder shaft as close to the transom as possible and still be able to rotate - I’m not keen on outside rudder linkages. As it is set-up at the moment it gives about 35* swing either way. The rather jaunty angle of the servo allows for the fact that their arms never seem to be square to the main axis, and this way I don’t have to use the Tx trip lever.
I hasten to add that this arrangement hasn’t run yet - but I have great hopes.
I ran my Glass Petrel with the in-line tiller arrangement shown above at our pond this afternoon, and she steered like a dream. One advantage of this kind of arrangement is that a 90 degree rotation of the servo arm does not limit the angle of turn available for the rudder, In my set-up here, the rudder turns through a greater angle than the servo. I would also point out that this arrangement is ideal for narrow-transomed or canoe-sterned designs, without needing to have above deck or out-past-the-stern mechanisms. A further refinement might be to have the adjustment of the ratios of turning angle reduced to merely a thumb nut, under a hatch.