[ARC5] ARC receiver dynamotor screw seals

[Mike Morrow]

Clare wrote:

> Swaged cups hold the cute little lead seals over the screws.
> In order to service the dynamotors you have to destroy the
> cups and seals and then drill out the back of the cups so they
> can be removed.

It's true that every DY-2A/ARR-2 dynamotor I've seen does not use the lockwired screws on the end covers like the DM-32-A, but all I've ever had to do is dig out enough of the soft lead to get a screwdriver blade on the screw heads, then back out both cover screws incrementally to get the end cover off.

> I suppose the chances of ever having to change brushes or
> grease before the plane was destroyed were very slight during
> the War so ease of maintenance was not a real concern back then.

I don't think these sets were made as deliberately expendable items.  In fact, construction quality is excessive, and the manuals have dynamotor maintenance instructions therein for brush replacement, lubrication, and bearing replacement.  Some (but not all) DY-2A units have spare brushes stored in plastic capsules under the end covers.  The ARC-5 manual gives 1000 hours as the service interval.

Mike / KK5F