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[Martin (Admin)]

Via email to Mayhem ....

I am just building my first model boat, how do I know where to drill the hole for the prop to pass through the bottom of the hull?
Your thoughts would  e greatly appreciated.

 B
 

 

[Mark T]

Generally the hole is not a hole it’s a slot. It’s determined by many things such as the type of boat or ship and its purpose.


I think we need to know more about the model in question but I guess it could be worked out another way too.


The propshaft needs to be inline with the motor and they need to be set at an angle that allows the prop to be efficient and not contact the underside of the hull.

[Martin (Admin)]

Additional ....

I am building a Halvorsen seaplane tender  as featured in the 2012 winter Model Boats mag. My question is how do I find the right place to exit the prop through the bottom of the hull. I have already fitted the motors and mounts.
Any help would be most appreciated. B

 

[Colin Bishop]

Just had a look at this article in the Model Boats Archives.

It is not a beginner's model and quite a complex build. The plans (which I don't have) apparently suggest a jig to position the twin shafts and the details and measurements should be apparent from the plan and the accompanying article. An inexperienced builder might find this a bit of a problem.

The shafts should be fitted first before trying to mount the motors.

Colin

[Martin (Admin)]

 


https://www.modelboats.co.uk/1224/halvorsen-seaplane-tender/
 

Also - http://www.ayrmodelboatclub.org/Halvorsen_Seaplane_Tender.html

[dodgy geezer]

Via email to Mayhem ....

I am just building my first model boat, how do I know where to drill the hole for the prop to pass through the bottom of the hull?
Your thoughts would  e greatly appreciated.

 

If you are going to continue with the model build as it is (without going back and setting the prop shafts in place before the motors, I might do something like this:

• 1 - mark the expected position of the prop shafts end on the bottom of the hull, using the plan for reference and a caliper to ensure that the props are the same distance from the centre line......
• 2 take a short piece of brass tubing which fits snugly over the motor shaft......
• 3 slide the brass tube along inside the boat, cutting a hole in any bulkhead, etc to allow it to lie straight on the motor shaft........
• 4 end up drilling a hole in the bottom skin where the brass tube hits it.
• 5 turn the boat over and see if the holes match your initial markings. If the don't, adjust the motor mound and cut more away until they do.
• 6 fill or plate over any excessive cutaways inside the hull with off-cuts.
• 7 mount the prop shafts using epoxy to seal everything

The above approach is given without looking at the plans or your hull, so it may be impractical..... but at least it answers your question by suggesting a way ahead...