Model Boat Mayhem

Mess Deck: General Section => Model Boating => Topic started by: TugCowboy on May 20, 2020, 01:30:40 pm

Title: Identifying thread on prop
Post by: TugCowboy on May 20, 2020, 01:30:40 pm
Doing a bit of cleaning out recently and found these props which I got from prop shop about 5 years ago for a model I've been working on for easily double that time.
Only issue is I can't find any of my order details. I remember they were a custom order to fit the Korts that I had made for it but I can't remember what thread they took.(https://i.imgur.com/jW5ptEs.jpg)(https://i.imgur.com/gw4QfMv.jpg)

I'd like to order the shafts so I can crack on with the model. Is there any way I can check what the thread is other than ordering a load of shafts and seeing which ones fit? I've no other large models at the moment so don't have a M5 shaft (which I think it is) to check.
All my other Prop Shop large scale props have been M5 but these are such works of art (and cost over 100 for the pair IIRC) so I don't want to destroy the thread by trying a load of mis-sized options.

Clever tips for determining a thread anyone!?

Alex

Title: Re: Identifying thread on prop
Post by: DaveM on May 20, 2020, 01:39:25 pm
Would it be too simple to suggest obtaining a plain M5 machine screw and trying that in the props? I'm sure B&Q will sell you a pack of five for about a tenner! Screwfix's are around 2.70/25 - still cheaper than buying a shaft, especially it it turns out to be the wrong size.

DaveM
Title: Re: Identifying thread on prop
Post by: Stan on May 20, 2020, 01:46:49 pm
HI just spoken to prop shop could be M 4 or M5  would agree simple check get old of a m 4 bolt it that fits  if not try M 5


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Title: Re: Identifying thread on prop
Post by: TugCowboy on May 20, 2020, 01:50:52 pm
Thanks guys, that was my thinking - I was just wondering if there was some clever way of measuring them. I'll get hold of a M5 screw and see if that fits - probably better off trying the larger size as it's unlikely to fit if it's right as opposed to forcing a M4 in there and ruining the thread.

I'll report back, I might have thought of something that'll work a bit better than having to buy packs of bolts.
Title: Re: Identifying thread on prop
Post by: Stan on May 20, 2020, 01:55:11 pm
HI If you have Wilco store near you they may be the cheapest good  luck hope all goes well.


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Title: Re: Identifying thread on prop
Post by: john44 on May 20, 2020, 07:53:26 pm
Have you tried measuring with the inside measuring jaws of a vernier gauge?


John
Title: Re: Identifying thread on prop
Post by: malcolmfrary on May 21, 2020, 09:53:37 am
Have you tried measuring with the inside measuring jaws of a vernier gauge?


John
From the fount of all knowledge (google search), metric inside diameters are - M4, 3.424mm,  M5, 4.134mm.
Probably enough difference to eyeball (or eyeball plus magnifying glass) with a ruler.  Outside diameter of M4 is 4MM, so should be a sliding fit into an M5 hole.
Title: Re: Identifying thread on prop
Post by: TugCowboy on May 21, 2020, 10:30:44 am
Being a Yorkshireman by birth I didn't fancy spending a couple of quid to get the wrong bolt.
So in about 15 mins this morning I 3D Printed a M5 bolt (and a nut to clean the threads first) and tried that in my props. The idea being the soft plastic wouldn't mess the threads up if it was wrong was also a deciding factor.
(https://i.imgur.com/mDZnfk2.jpg)
Et voila the M5 fits perfectly. Now time to find some shafts and get them ordered. Thanks for all the help guys.

Alex
Title: Re: Identifying thread on prop
Post by: Nordlys on May 21, 2020, 01:31:46 pm
Your skills surpass your thread question without doubt!
Job done!
N.