Tow Plate for IV

OK. Thanks, Chuck.

I'm going to speculate the bend was so that tow bar didn't scratch the nose fork (which does on my Legacy with flat plate).

Paul, not sure what the difference is but mine doesn't interfere at all, with either the tow bar or the tug. The dimensions of my newly fabricated plate were taken directly from the original one. I wonder if dimensional changes were made by the factory somewhere along the line when they put the 45 deg bend in the plate, given that your tow bar interferes with the nose gear fork???

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Last edited by Chuck Walker on Fri Oct 27, 2017 4:20 pm, edited 1 time in total.

this is the flat piece on the Legacy. the red boxes occasionally get scratched by the bar when installing. I bet larger tow bars might interfere also. I think the cutout could easily be duped by the guys who cut my panel (they love repeat jobs on their CNC) but I don't know who would do the welding. I'm guessing the metal cutouts with holes drilled at $5-10 each delivered. The attachment bar and welding is another step.

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I need one as well for my in-progress ES. Brian showed me his spare a few weeks ago, and explained that it is designed to fail if too much force is applied. This is accomplished, I believe, by intentionally placing the mounting holes too close to the inside edge of the piece. So assuming that all that is correct, it's not just fabricating a plate. It would have to be the correct metal and the correct hole to edge dimension. I'd be interested in design drawing and metal specs, as making one up would be pretty easy.

The pins should visibly deform if too much force is applied. They would be the typical and easier method of calculating the force needed and causing an owner to inspect the event. I am skeptical that the hole pattern is intended to cause failure and break away. Having said that, I've made more than 200 sets of TBM tow pins that use the soft pin design and it has worked well over a decade. Someone has copied the design and now supplies them inside the owner organization so I don't make them anymore but the concept works and replacing them afterwards is cheap. They were about $50 selling price at the time.

If Lancair has specs for the part I'd be happy to help out and source it. If not, I'd remove mine or seek a copy to have duplicated in large quantity.

Just for fun, I created a job on eMachineShop for a visually similar product. Steel, 0.25 thick, some holes and a bend. It is not accurate. It is just for demonstration and pricing. The cost is around $25 delivered for this piece in lot sizes. The pin would have to be added/welded or possibly machined in place.

That gives us an idea of what the plate should cost. About a week to deliver.

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I see Chuck's photos. Should be easy enough to make, from that. Thank you.

Lancair says it will not be soon, before they can get this part instick

Scott, I don't know whether the IV uses the same nose gear assembly as the Legacy, but I can give you length and width measurements of the plate and length of the rod if that would be helpful. The back side of the plate just has to be shaped as seen in the photo.

Paul,
Your design with 4 holes seems better. My original bent towplate has too big holes and keeps moving slightly sidewards when steering with towbar.
If mounted under a he shoe of the strut, you would need the bent version to get clearance to the fork.
I might need a plate as well as my pins are bent. I never liked the original one with the too big mounting holes. I’d prefer to drill Thomas myself to match the 360 fork.

Christian