Prop nut

[blindpew]

Can some one tell me if Blackjack 29 prop nut thread is unc or unf please.

[blindpew]

I have damaged the thread on the flex shaft of my blackjack 29 so I need to borrow a die to clean up the thread.Surely some one out there must know if it is a coarse or fine thread that I need.Anyone?

[CraigP]

If it’s stock it’s probably a metric 4mm? Are you sure it’s a UNF thread? Most prop shafts made here have a 10-32 thread, which is UNF... Without knowing for sure, I would replace the shaft. If you pick the wrong tap then you will ruin the thread.

[blindpew]

If it’s stock it’s probably a metric 4mm? Are you sure it’s a UNF thread? Most prop shafts made here have a 10-32 thread, which is UNF... Without knowing for sure, I would replace the shaft. If you pick the wrong tap then you will ruin the thread.

Thanks for the reply CraigP.The nut is a loose fit for an 8mm socket but a perfect fit for 5/16 AF socket,the shaft thread is just a little smaller than 8mm so if no one can tell me the correct thread size I will have to junk the shaft.Cheers.

[fweasel]

If its the stock cable, take it as an opportunity to upgrade to a better quality cable from OSE.

[blindpew]

If its the stock cable, take it as an opportunity to upgrade to a better quality cable from OSE.

I could upgrade the flex shaft but I would still like to know what the thread size is.Surely with all the blackjack and miss geico owners on this site someone must know.In the UK we use metric sizes so I know that my revolt 30 has a 4mm nut with a metric thread so surely in the US by looking at it you should be able to tell if the prop nut is 5/16 unc or unf or if it is neither.Cheers.

[fweasel]

I've owned three of them, and have never once measured the thread pitch of the propshaft, nor on any of my boats. It's never been an issue. At the moment, I don't have a stock V3 cable on hand to check. Sorry.

[MADRCER]

My stock MG29 v3 cable is UNF 10-32 threads.

[CraigP]

I have never seen a UNC thread on a prop shaft 3/16” or smaller. I’ve never seen a 5/16” nut being used in that size range either. I blow the metric stuff out, use all the same stuff across all my boats, 1/4” X 10/32 thread nuts. I would suggest going to the local hardware store and get both a metric and SAE thread pitch gauge sets so you can answer your questions about that.

[blindpew]

CraigP I live on the island of Jersey which is 10x5 miles.We do not have hardware stores with thread gauges.We do not even have a shop that sells boats or lipos so I have to send away for every bit I need.That is why I love this forum because the people are so helpful.MADRCER has told me what I need to know so thanks everyone.Cheers