1/4" delrin tube for bent losi links help please

[downhiller6325]

ok so i just got in my delrin today and am planing on using the 1/4 delrin for my links ive read that the bent links want work but i have seen a couple with bent links just nothing drastic because i dont want the drive shaft to hang down below the links. ive read that i need to thread 4mm all thread through the 3 mm hole even thought it was supposed to be 1/8 iner diameter. i was just wondering if there was a diy tech or thread that could show me wat to do or if someone could guide me in the right direction. thanks for the help.

[Reflection]

Going by a drill chart,for a 4mm thread,they call for a 3.3mm hole.

In delrin,the all thread would probably thread itself if the ID of the hole is 3mm. It will be very tight though. I would imagine going all the way through the link with all thread,it'd get pretty hot,may even distort or stretch the delrin. If your set on doing it,I think the best way to do it would be drilling the ID out first.

Get a #30 drill and drill the tube out if you want a full thread on the entire ID. Since your using all thread and not really relying on the thread inside the tube to hold much,you could drill it bigger. A #22 drill,or a 5/32 drill will drill it out tight,but you won't have a thread inside the tube.

Could go with a #24 or 25 drill. When threading the all thread into the delrin tube after you drill with a #24 or 25,you'll get a partial thread. Enough to hold it snug and make sure it's a tight fit.

[downhiller6325]

thank you for the help ill look into getting some 4mm all thread... i have the bit. will my losi rod ends still work with the tube drilled out?

[pbarsamian]

I've snapped off zinc plated steel screws in delrin from over tightening, suggest treating it just like Aluminum when drilling and tapping (in other words follow the drill chart and use a good tap to cut threads).

You can get those drills pretty cheap, in fact you can get indexed sets of metric drills and taps at places like Harbor Freight very inexpensively.

[Reflection]

Originally Posted by downhiller6325

thank you for the help ill look into getting some 4mm all thread... i have the bit. will my losi rod ends still work with the tube drilled out?

You are planning to run the all thread all the way through the delrin link correct? Not just a small sections or short set screws at the end?

1/4" delrin tube,even 1/4" solid round,will never hold up as lower links unless you've got some quality all thread running through the middle end to end.

I don't see why the Losi ends wouldn't work. I would recommend using a spiral flute tap and tapping the rod ends for a 4mm thread. A spiral flute tap would be much better than a spiral point tap as they'll get closer to the bottom of a blind hole. Spiral point taps will push the chips into the hole. Spiral flute taps will pull the chips out of the hole. Specially with little taps,chips built up in the hole is a quick way to brake taps. Allot of spiral flute taps are 3 flute,that makes them stronger in most cases than your typical 2 flute spiral point tap.

[stubs179]

I think you should get a stick of 3/8 solid delrin. It will work better and you can file the bottom flat so it doesn't stick down so far but will still be strong. I will be much easier as you only need to drill the ends and install your set screws.