The Sinclair QL Forum

tofro wrote:Drill and file.

Old-style, but precise

Step 1 - carefully mark the cut-out
Step 2 - drill a series of holes next to each other in a line just inside the marked lines (while being very careful not to stray near the marked lines). Use a 3 to 4mm drill bit at a slow/medium speed.
Step 3 - use a metal "nail" file to expand and link up the drilled holes.
Step 4 - use a larger flat file to expand the hole to the marked lines.
Step 5 - use a fine flat file to finish the cut-out

Job done

It does require skill and patience

Mark

Dave wrote:
How did you get such a clean cut on the ABS?

Pretty much as Mark and Tobias posted; drill holes and lots of careful filing.

First I marked out the aperture in the ABS by scoring outline with a craft knife (pencil/indelible pen easily becomes too indistinct when filing). Then I drilled a couple of holes at each corner and used a loose hacksaw blade to cut alongside horizontal lines, rasp filed off the excess, and then did fine work with small files.

Picture attached shows placement, I had to bend a couple of pins to avoid internal plastic pillar, wire was Kynar 0.25mm. In retrospect I guess it would have been easier to wire data & some address lines off back of ROM port connector. Because of the pillar (and centering) you cannot quite use both ROM port & DIN together, (although Miracle hard drive lead is OK). But this was not a consideration for me, ROMOEH enables quick prototyping, pity the unused pin on ROM port wasn't wired to R/W. (ROM port MHD & MIDI interface circuits posted in qlhardware/Files/Transfer)

The only thing missing is a neat black DIN cover like ROM port etc.

While I had the QL case disassembled I also resited the loose Qimi mouse connector. I like to think both mods nicely retained aesthetic appeal of uncluttered black box.

[quote="Silvester[
The only thing missing is a neat black DIN cover like ROM port etc.

While I had the QL case disassembled I also resited the loose Qimi mouse connector. I like to think both mods nicely retained aesthetic appeal of uncluttered black box.[/quote]
Very nice job, Silvester. I really like both case mods, the QIMI mouse connector is very well placed too.

As for the neat black DIN cover, might be a job for Dave and his 3D printer!

dilwyn wrote:As for the neat black DIN cover, might be a job for Dave and his 3D printer!

Don't go volunteering me for things! It would be trivial to print though.

I did have some success printing power socket shrouds for RA 3-pin power connectors, so when my current supply runs out I can make more. Not perfect, but functional. I have also printed prototype battery adaptor covers (they provide mechanical support to the battery holder) then acetone bathed them to smooth the surface.

For things 3D-printed it would probably make a lot of sense to print in the destination country - On-demand service providers like Shapeways would allow that - Saving overseas postage could be an issue here.

Tobias

A good thing files can easily be emailed.

Shapeways is actually a sales platform - You supply the design (usually using an STL-file), they print and ship. You tell them a price, they sell, charge and ship. You get what's left over after deducting manufacture cost, shipment and their margin.

Dave wrote:then acetone bathed them to smooth the surface.

Ohh this is a new thing to me. I have seen many 3D printouts and not impressed by the quality at the affordable end of the spectrum.

So Dave, tell us more about this acetone bath, if in there too long does the object completely melt away?

There's a movie on hackaday that explains the process in detail - The printed product is "bathed" in boiling acetone vapor. Sounds a bit scary to me.....

http://hackaday.com/2013/03/23/smoothin ... one-vapor/

Tobias

There's two ways of doing it.

The easy way is to dilute the acetone or use a buffered acetone product like commercial nail polish remover (which is dyed pink)... Simply rub the ABS print-out to obtain the finish you'd like.

The proper way is to place the plastic hanging in a non-soluble container (a hot glass container is ideal) then heat a small tray of acetone - it will evaporate and fill the jar bottom up with vapor, which will condense on any cooler object suspended in it. The effects can be quite pleasing, but it does affect *every* contacted surface. On removal, the surface remains soft for a short period, so you can texture it, for example by rubbing course fabric, leather or etc against it. Pressing washed course sand onto it gives a similar rough finish to the QL case.