Hot end / extruder problem

Hi, I am very new to Reprap etc.
I just built a Metric Prusa Mendel with bearings
Using MKII hot bed
Using self-made hot end, 16mm diameter PEEK rod, cut to 40mm, centre drilled to 3.5mm, counter bored for ABS entry, M6 blind tapped to depth 10mm for hot end, M6 steel rod 30 mm long centre drilled to 3.5mm attached to PEEK, M6 steel dome nut with 0.35 mm hole screwed to end of M6 rod. 6 ohm of nichrome wire wound around M6 rod.

Using pronterface (printrun), I can extrude 5mm, ABS goes in (calibrated) ok, but ABS does not start to extrude for a few seconds.
I have tried 230, 240 and 250 degrees, that does not seem to effect it.
Maybe I need to line PEEK with PTFE?
Any suggestions?

I was going to make my own hot end when i started but after looking some things up i found that just getting one off line was the better way to go. i currently have a j-head .5 mm from hotends.com and its working grate! and for $55 its very worth it

But if you really do want to make your own i would say having a 3.5 hole is not the way to go. you need your abs to be very snug in the shaft of the hot end or else it will start to come up the sides and not extrude very well at all.

I found out the very hard way never to get ABS up to 250 with PEEK because it melts at 245 and I've melted a few ends in the past. i have mine at 220 when i print and the abs just falls out fine.

PTFE liner is always a positive. It will add additional lubrication for the filament to slide through.

As far as hole wise I agree with Benjamin. Larger is not necessarily better for your filament guide hole. Think of the melted filament like a plunger. If there is extra space around the filament molten plastic can be pushed back up, cooling, and jamming. Same can be said at the joint between your threaded rod and nut (nozzle). If this is not properly sealed plastic can sneak into there and cause the same thing.

My first reprap had this style of hot end and failed constantly. It was later replaced with a J-head style.

It's a good idea to have a PTFE tube inside the PEEK.

We have been getting good prints at 240 degrees with ABS.