Anders Pedersen / Tip Top Workshop PKD blaster build

[Ekfud]

If it's not too much detail to ask - how did you get on with tapping all the holes for this? I've been finding I'm chewing up the first 2-3mm of the M3 holes before the thread starts to bite properly (on some practice pieces of resin). I've had a bit more luck starting a thread by just carefully screwing in an M3 bolt, but there is a fair amount of resistance and can imagine for a couple of the holes (especially the tube on the back of the bolt handle) there is a lot more risk of cracking the pieces by forcing a screw straight in.

Interested if there were specific taps/tools or advice you had that worked best?
The metal sighting rod will be a whole extra challenge later

 

[wayouteast]

If it's not too much detail to ask - how did you get on with tapping all the holes for this? I've been finding I'm chewing up the first 2-3mm of the M3 holes before the thread starts to bite properly (on some practice pieces of resin). I've had a bit more luck starting a thread by just carefully screwing in an M3 bolt, but there is a fair amount of resistance and can imagine for a couple of the holes (especially the tube on the back of the bolt handle) there is a lot more risk of cracking the pieces by forcing a screw straight in.

Interested if there were specific taps/tools or advice you had that worked best?
The metal sighting rod will be a whole extra challenge later

I managed to tap most of the holes with no issues, though there were a couple I 'over-tapped' so the screws didn't bite properly when inserted. Where that happened, I filled the holes with JBWeld and re-drilled/tapped. I used a fairly cheap tap-and-die set that I've had for a while, bought off eBay - something like this one.

It's a really big help to have some light machine oil available; a drop of that in the hole before tapping, and again when the tap starts to 'stick', makes things much easier. That's pretty essential, I think.

I also found that tapping as far as you can go (until the tap starts sticking), then unscrewing the tap carefuly, thoroughly cleaning the hole of any swarf, and then gently screwing the tap into the just cut thread, allows you to go a bit further each time - in effect you're tapping the hole in a series of small increments rather than trying to do the full depth all at once.

Hope this helps. Good luck!

 

[Ekfud]

I managed to tap most of the holes with no issues, though there were a couple I 'over-tapped' so the screws didn't bite properly when inserted. Where that happened, I filled the holes with JBWeld and re-drilled/tapped. I used a fairly cheap tap-and-die set that I've had for a while, bought off eBay - something like this one.

It's a really big help to have some light machine oil available; a drop of that in the hole before tapping, and again when the tap starts to 'stick', makes things much easier. That's pretty essential, I think.

I also found that tapping as far as you can go (until the tap starts sticking), then unscrewing the tap carefuly, thoroughly cleaning the hole of any swarf, and then gently screwing the tap into the just cut thread, allows you to go a bit further each time - in effect you're tapping the hole in a series of small increments rather than trying to do the full depth all at once.

Hope this helps. Good luck!

Thank you - slightly reassuring that a couple going astray isn't unheard of.
I'm probably not too far off on the process, and I've found doing larger (~M6 or M8 holes) pretty straightforward.
The M3 holes I wonder if I didn't clean out debris well enough between reinserting (mainly on the tap itself).

Thanks for the extra detail - half the fun of this kind of project is learning new skills.