Rear motor twist anchor

[Jmk89]

As requested by Richard (Lastwoodsman) here are the posts on how to use this device (stl files to 3D print available here  https://hpa.aeromodelling.gr/plans/details.php?image_id=2099 with a Word document setting out some of these posts).

As foreshadowed, here are some photos and a description of the use of the rear motor twist anchor that I have that added to the Plans Gallery has an STL in a ZIP file.

For the sake of clarity, I have shown the operation of the equipment without use of a fuselage so that we can see what is going on.

The motor is made up in the usual way, with the rubber going around the round crossbar.  Make sure that the two prongs are oriented to the rear.

The two prongs are twisted to engage a convenient a winding peg (I used the crossbar from my winding stooge are for illustration purposes).

The situation once the motor has been wound.


Next, the two protruding lugs are put into a slot made in a piece of aluminium channel.


Then the motor end is held with a pin which engages in angled slots at about at an appropriate length. (Make sure that the length is greater than the length of the fuselage from the rear peg to the front so that the front hook is available to you have enough room to hook on the prop !)

[Jmk89]

Rear motor anchor use (cont.)

Then the aluminium holder is inserted into the fuselage with the prongs of the motor anchor aligned so that the faces are horizontal (this means that there is a space for them to go past the rear motor peg.

The next step is to twist the aluminium channel 90° so that the two prong hooks engage on the rear motor peg.


Finally, engage the prop shaft to your front hook (mine is a based on the old Tim Gray hook) and withdraw the aluminium channel. Then seat the nose block.

The only real trick is to remember that the diagonal measurement of your channel must be less than 10 smallest dimension of your nose hole. Otherwise, even if you can get the aluminium channel into the fuselage, you won't be able to twist it. DAMHIK!!

I hope that all makes sense.

By the way, I have drawn a revised version of the anchor with the outside lugs extended to 10 mm each side. You don't need the whole 10 mm, but it may be useful sometimes to have longer lugs and cut them to size to suit your particular installation.

[OZPAF]

thanks for the detailed coverage and pics Jeremy.

John