Hi all

Just some additional feedback on my experience on the step drill. As the name implies a single bit has multiple sizes so cost saving on buying - bought a set 3mm to 15mm for less than £6. In testing, there is no grabbing and it just works. Drills clean every time and no issues yet.....  only issue is watching you don't go to the next size when at correct hole diameter.

I found this tip on YouTube from guys that rebuild arcade machines and regularly drill Perspex - their recommendation tried and tested 😄

Works for me and thought I would share.

BR
Chris

Quote from: Takamine on July 03, 2018, 05:16:39 PM
Drills clean every time and no issues yet.....  only issue is watching you don't go to the next size when at correct hole diameter.

An old trick I use when drilling to a size/depth is to wind some masking tape round the drill leaving the correct length before drilling. Just drill down to the masking tape then. That's the cheap way.
I have seen collars used with a small bolt in the side to tighten down onto the drill but it only does the same thing.

Quote from: The Q on July 03, 2018, 08:24:28 AM
You are better off using drill bits specifically ground for drilling acrylic..

https://www.theplasticman.co.uk/products/tools-drill-bits-etc.html

they are much less likely to "grab" the plastic and cause chips and splitting..

there are much cheaper suppliers around, that was just the first site I came across with them..

found  cheap ones on EBAY
https://www.ebay.co.uk/sch/i.html?_odkw=drill+bits+for+plastic&_osacat=0&_from=R40&_trksid=m570.l1313&_nkw=drill+bits+for+plastic+slow+spiral+drill&_sacat=0

Or if you have a bench grinder sharpen the point to 60 degrees. A standard drill point angle is about 120'

An approximate simple drilling speed guide for Acrylic (Perspex®)

1/8" drill = 3500 rpm
1/4" drill = 1800 rpm
1/2" drill = 900 rpm
1" drill = 450 rpm

If your drilling deep holes you should "peck" the drill to prevent it clogging. If drilling a number of holes then put a little water in a small container to use as a coolant to dip the drill bit in, this will prevent it getting hot and melting the stuff!

should you manage to scratch the PX , don't worry it can be polished out using the finest wet 'n dry paper (wet)  then polished with T cut or Brasso .

I just got the "new in" newsletter from 4D modelling co which I get a lot of stuff from.
As well as some different blends of ballast, some stone wall sheets (a bit big for our scale) they have Perspex sheets now in .....

http://modelshop.co.uk/Shop/Item/Perspex-large-sheet/ITM8015

All best wishes
Kevin

Hi all

Well redid mimic panel with step drill. Used a hand held power tool - no drill press and found it very easy. Looks like this and you can see how close some of the holes are - no mishaps at all! There are one or two starry edges where I was overenthusiastic with the pressure - learnt quickly to let the drill feed. Its great to be able to do this without waiting for something to go wrong.

BR
Chris

Which will look like this  - very happy with the result

BR Chris

That looks superb Chris, nice panel.   

Excellent!

Dave G