Kayfun lite fill screw problem

[thatguy]

I bought a KFL from fasttech and after filling twice, the fill screw just wont play nice.  Can only assume poor threading on the base.  Was this beastie.  Anyone else had this issue?

Is it feasible to drill out the hole to 2.5 mm and tap at M3x0.5 and replace screw and silicon washer?  Really getting my goat as she whom must be adored really love this RBA, and was hoping to be able to use the Russian in transit myself (she'll commandeer it if the kayfun is dead).

[chykensa]

Either that or admit defeat, superglue the bottom fill screw in place permanently, and fill from the top. I am wary of bottom screws after a mate's Russian lost the threads, so I always top-fill these days, and it's relatively pain-free, just a few drops of juice down the chimney after filling, gurgles for the first 4 or 5 pulls as the vacuum pressure builds, then away we go.

[igual]

Yes tapping should be Np but fully disassemble atty and remove centre pin as you need to make sure all swarf is removed from all noocks and crannies.

[thatguy]

Will do igual . Luckily got a workshop at my disposal at work. Think I'll replace the post screws as well with ones with slightly larger head to make rebuilding a bit easier.

[igual]

Hmm workshop at your disposal hmmm hello
I soo miss my workshop had milling machine ,pillar drill , metal and wood lathes screw cutting lathe. Metal formers full sized anvil.band saw, chop saw.
Mig , tig, arc welders compressor and associated tools.

Now all I got is my silversmithing bits mini lathe dremel and cordless drill lol

[ronaldo]

not to sure so you may have to check it out but I think a M3 screw thread needs a 2.4mm hole I am pretty sure you need 0.6mm for the threads

[thatguy]

I have m3x0,5 taps and dies on hand ronaldo so 2.5mm seems right. 2.4mm could yield great threads as well but with extra stress on the taps and more swarf to deal with. The base material on the KFL doesn't seem to be that hard so making sure all swarf was clear could mean the difference between a good thread and a disaster. 2.5mm has been reliable in my experience so far with both Steel and aluminium alloys.

checked a few charts and they all state 2.5mm for the drill as well. Since I'm going to be using a 3 part snap-on taps I could probably manage 2.4mm, but 2.5mm is the stated drill size from snap-on.

[thatguy]

Sept 14, 2014 23:40:34 GMT igual said:

Hmm workshop at your disposal hmmm hello
I soo miss my workshop had milling machine ,pillar drill , metal and wood lathes screw cutting lathe. Metal formers full sized anvil.band saw, chop saw.
Mig , tig, arc welders compressor and associated tools.

Now all I got is my silversmithing bits mini lathe dremel and cordless drill lol

I'm lucky enough to have these and CNC mill, router and laser cutter, as well as a forge, planer and various finishing machines.  God bless Scottish D&T education.

[VapingBad]

thatguy FT do these top fill caps £3.50, I know it won't help for a few weeks, but there is a UK vendor though I forget who.

[archiecat]

Fill my Kayfuns from the top, finger over the air hole, squirt in the juice, thread the top in one turn, invert and complete threading the top cap home.
Works fine for me..

[Deleted]

Dumb thing to say but have you not tried vaseline/lip balm on the threads?

Just a wee girlie thought

[Ripshod]

On a few bottom fill tanks I've found that by turning the fill screw backwards til I feel it 'drop' into the threads makes it a lot easier and helps prevent any damage to them. Hope this isn't too late.

[thatguy]

Gonna try three solutions in order.

1. A longer M2.5*0.5 screw as it is the deck threads that are poor

2. Drilling/tapping to M3*0.5

3. Perma plugging the fill hole and top filling.

While I'm at it, I'll machine better screws for the terminals as the heads on the existing ones are small and a pain to coil.

Thanks for all the replies and advice.

[decoy]

Sept 15, 2014 23:34:39 GMT thatguy said:

Gonna try three solutions in order.

1. A longer M2.5*0.5 screw as it is the deck threads that are poor

2. Drilling/tapping to M3*0.5

3. Perma plugging the fill hole and top filling.

While I'm at it, I'll machine better screws for the terminals as the heads on the existing ones are small and a pain to coil.

Thanks for all the replies and advice.

just a quick heads up paw broon 
the heads on kayfun screws are small so they dont short out on the sides might be worth keeping an eye on it
wouldn't bother with a longer screw i tried it on one and it didnt last a week
hope that helps

[thatguy]

Drilling out at 2.5mm and tapping M3x0.5 worked a treat. She who must be obeyed happily sucking on it again. Thanks for advice all.