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.