Fitting a tiller arm for autopilot in a tight space

[Matt Johnson]

Originally Posted by SailRedemption

That Jefa unit would work fine. It's not cast and is made for supporting a ram of some sort.

Also, to second Matt's response, our boat came with a Type 1 or 2 linear drive attached to an Edson full circle quadrant(or whatever the term is for the full round ones) so the PO had success for a long time. We took that out and are going with a hydraulic ram mounted to a custom tiller arm made by our machinist.

Your third option being one made by a welder or machinist. This is what we are doing because no one makes tiller arms that aren't custom for 4" rudder shafts. We also needed a split collar type. Here is a picture of ours in the process of getting made. It's 3" thick aluminum for more grip since we can't/won't thru bolt it. It's clamped together with 4 x 1/2" socket head bolts. It has a 1" plate welded to it for the tiller. Attachment 187214

Man, you're giving me an inferiority complex with that beast.

Ours was just split with a band saw and theb tapped to hold 2 x 3/8" bolts. We did put one bolt through the shaft as we'll (can't remember the size of that) but the clamping force of the two 3/8" bolts seemed to be just fine and there was no evidence that the through bolt ever took any torque.

Matt

[Tessellate]

Originally Posted by SailRedemption

Here is a picture of ours in the process of getting made. It's 3" thick aluminum for more grip since we can't/won't thru bolt it. It's clamped together with 4 x 1/2" socket head bolts. It has a 1" plate welded to it for the tiller. Attachment 187214

Wow that thing is a beast. How is the arm attached to the clamping block? Looks like perhaps it's not attached yet, and is going to be welded on?

Did you have to come up with the design and dimensional drawings or did the machine shop do that? I'm calling some machine shops (in Seattle area) but a lot of them don't want to work with sailors on a one-off - they have plenty of industrial orders on the 1000+ count scale to keep them busy.

[SailRedemption]

Originally Posted by Jim Cate

I'd be worried about ever getting them out using loctite with that much bury length, and with so much mass that heating the tiller to release the loctite might be iffy.

But I'm only going on instinct here... perhaps a more knowledgeable person might advise on the matter.

Jim

Originally Posted by stormalong

Use Loctite blue and only one drop per bolt.

Yea, blue loctite (red bottle). It's not super hard to bust loose and you and if you need to heat it it doesn't take much. I thought about Tefgel but it stays slippery and may work loose? I don't know much about that's stuff which is why I fell to the loctite.

[SailRedemption]

Originally Posted by funjohnson

Man, you're giving me an inferiority complex with that beast.

Ours was just split with a band saw and theb tapped to hold 2 x 3/8" bolts. We did put one bolt through the shaft as we'll (can't remember the size of that) but the clamping force of the two 3/8" bolts seemed to be just fine and there was no evidence that the through bolt ever took any torque.

Matt

[emoji23]
Well we didn't want to thru bolts our 4" rudder shaft which we assume is hollow. We were going to go with 2.5" thick clamp but the metal supply only had a 6"x12"x3.5" block of aluminum on hand so I grabbed that.

I will slim it down some and shave the corners off and make it less beastly. I know one of your tillers is exposed to elements, do you find any corrosion that may have been avoided by getting it anodized?

[Jim Cate]

Originally Posted by stormalong

Use Loctite blue and only one drop per bolt.

While one drop of blue might keep the bolt from unscrewing, it would not do the sealing job that the OP is needing to keep the s/s bolts from seizing in the aluminium tiller clamp. He needs to exclude water completely.

Jim

[SailRedemption]

Originally Posted by Tessellate

Wow that thing is a beast. How is the arm attached to the clamping block? Looks like perhaps it's not attached yet, and is going to be welded on?



Did you have to come up with the design and dimensional drawings or did the machine shop do that? I'm calling some machine shops (in Seattle area) but a lot of them don't want to work with sailors on a one-off - they have plenty of industrial orders on the 1000+ count scale to keep them busy.

The arm will be welded thoroughly as well as the brace.

I am using a friend of the family who owns a shop. I'd look into places that do small parts and such, like a mom&pop type shop. I didn't design anything really, I just told him I needed a tiller arm about 9" from center to center (with holes further and shorter too) and a rudder shaft diameter. I also brought the L&S ram clevis end so he knew what size bolt to use for the tiller attachment. I showed him a diagram I got from PYI so he had an idea.

[stormalong]

Originally Posted by Jim Cate

While one drop of blue might keep the bolt from unscrewing, it would not do the sealing job that the OP is needing to keep the s/s bolts from seizing in the aluminium tiller clamp. He needs to exclude water completely.

Jim

If the bolts pass though the clamp and are secured with nuts the answer is anti seize compound and nyloc nuts. Best of both worlds.

[SailRedemption]

Originally Posted by Jim Cate

While one drop of blue might keep the bolt from unscrewing, it would not do the sealing job that the OP is needing to keep the s/s bolts from seizing in the aluminium tiller clamp. He needs to exclude water completely.

Jim

Originally Posted by stormalong

If the bolts pass though the clamp and are secured with nuts the answer is anti seize compound and nyloc nuts. Best of both worlds.

Ours is threaded inside the aluminum block. No nuts for the clamp. So the stainless bolts need to be coated so the don't corrode the aluminum.

[stormalong]

Originally Posted by SailRedemption

Ours is threaded inside the aluminum block. No nuts for the clamp. So the stainless bolts need to be coated so the don't corrode the aluminum.

In that case Duralac is a good choice. It hardens enough to hold a properly torqued bolt. Tefgel is a grease and I have had bolts coated with it back out under cyclical loads.