BJ4 hinge pin retention - how to improve?
 

A few times now, the rear hinge pins have worked their way loose, sliding forward or back and resulting in the pin bending and/or the wishbone breaking. It's getting tiresome hoping those fiddly little grub screws will hold the pins in place when they clearly don't work effectively.

Are there any tricks or mods to keeping those blasted pins in?

On mine I used to put a flat on the hingepin using a dremel cutting disk for the grubscrew to locate onto, just like a pinion.

Jimmy did the same in the BJ4WE review, top right of page 5...

http://www.oople.com/rc/photos/reviewbj4we/page05.html ;)

Cheers Richard, it's about the only niggling problem I still have with the BJ4. Still plenty of life in it if this works.

Would you recommend a tiny spot of threadlock or superglue on the grub to persuade it to stay put, or is that a bad idea near a hinge pin?

Threadlock for sure! The pin is meant to stay put in the blocks and pivot in the arm, so a bit of excess threadlock is fine so long as it doesn't impede the arm.

I used to dump loads on to make sure it never came out, in fact when I built a kit up usually the pins would stay put in the front block for the life of the car :p

I swapped the grub screws out for short 4-40 cap heads and just torqued em up. Never moved after that :)

You can also superglue the hingepins into the front block.

if you ever need to remove it, just heat the block and hingepin with a soldering iron. The other suggestions are good too.

I made the flats in the pins and used plenty of threadlock. I'll be ordering a load of imperial screws soon, I'll see if i can get stubby 4-40s. The same supplier does 1/8 and 3/16 grubs, the latter being 3 times cheaper!

Havnt ordered from this site yet but will be pretty shortley.............

http://www.modelfixings.co.uk/index2.htm

:thumbsup:

Yup i use Modelfixings to get screws and always been top service

£1.20 for 5 measly grub screws? I found a company selling 4-40 3/16ths for around £10 + VAT for 100, more in line with metric hardware prices.