The backstay bearing of my Freehand steering gear had incurred severe UV degradation. Not having affordable and ready access to a lathe, I machined a replacement using a drill press with a live center attachment. This, in essence, is a vertical lathe.
As shown in the attached photos, some nuts, flat and lock washers, threaded studs and aluminum bar stock enable control of cut depth and dimension. A couple of files, the appropriate drill bits, a tap and some wet & dry sandpaper are the tools required to machine a replacement backstay bearing.
The hardest things to find were the live center lathe attachment and appropriately sized black Delrin stock. Black Delrin has much better UV resistance than white Delrin. Here are links for these two items.
The Delrin stock required for one backstay bearing is 2 pieces of 1” black Homopolymer cut to 2” x 3.5” with dimensional cut tolerance of +.031/-.000. Due to Professional Plastics minimum order requirements, I was able to buy 6 of these and one 4” x 11.75” piece to replace the bowsprit fid at no additional cost. (My bowsprit fid also had UV issues.)
In the attached photo of the original white bearing, it’s clear that UV degradation has severely affected the upper and lower collars near the 4 machine screws that secure the two halves together. Therefore, I increased the vertical dimension of both collars to provide more material. The photo shows the difference between the white and black bearings’ collar vertical size.
Attached are a CAD drawing of the new bearing with the increased collar size and a step by step procedure used to machine the new bearing.
Use the lowest drill press speed and work slowly when machining Delrin. Drilling and tapping Delrin requires plenty of cooling lubricant; a solution of 25% liquid dish soap and 75% water works well.
Wah! Superb work, very valuable information. Thanks very much, John. You’re fantastic.
I’ve Zygote’s Freehand off the boat for three years now, trying to work out how best to do something like that. The white Delrin (originally used also in BCC 116 Zygote’s bowsprit fid and that dogbone (as Mike Anderson called it) fitting in the Freehand, did not take tropical sunlight well.
I replaced the bowsprit fid with a timber fid after only a few years.
I’ve struggled on with the dogbone bearing (painting it with varnish has been surprising effective at slowing UV degradation of the Delrin). In fact, most any spar varnish has lasted surprisingly well on anything except timber (e.g. accidental drips on the gelcoat, deliberate brushstrokes on Delrin).
I’ve been busy and not reading the Forum lately.
I note from your post in the Equipment sub-forum that you’ve sold BCC 122 Adventure (2003) and are heading to the mid-West.
I (and I’m sure other Owners) would be v interested in any wisdom you would care to impart after your long experience with two BCCs. You’re one of a small handful of Owners who have had two.
When I’ve been aboard other BCCs, I’ve noted differences. Not just in the cosmetics, but real differences in mast height, mast rake, bowsprit length (and hence size of jib topsail etc), location of jib sheet turning block, location of (and range of adjustment in) staysail sheet turning block; to name the big ones.
I’d be particularly interested if you were to address those sorts of differences. I’m guess that BCC 122 would not be very different from BCC 116 Zygote in those structural elements. How similar was your 2003 BCC to your 1987 one? What differences in how they sailed?
I just visited my freshly refurbished freehand steering system at Mike Anderson’s shop yesterday. I plan to install it tomorrow morning with Mike’s help. I’ll post a picture or two of it.
As a new owner, I’m also very interested in the difference and possibilities in rigging configurations. When we stepped the mast last week my rigger noticed what he called “a bit of prebend in the mast up high.” I’ve also been figuring out where to place/attach the leads for the different headsails and how to adjust them. Finally, a rigger buddy of mine was remarking that rigs like that on our BCCs normally incorporate running backstays to keep the rig from pumping. Perhaps this topic is worthy of its own thread if it’s not already in existence.