Cutting for a flush mount trackball

[dth930]

I need to cut a CP & CPO for a flush mount Ultimarc U-trak trackball.  It's going into a CP that's vinyl over plywood with no plexi.

I've seen a number of ways to do this, the most common seems to be applying the vinyl then cutting the hole with a knife as you would for buttons and joysticks.

After a trial run of this method, I don't think it's going to work.  I tested the process using a speaker hole and the resulting edge around the circle is not smooth and even enough.  It's not bad, but you can certainly see inconsistencies in it.

Has anyone used another method successfully?

The two other options I've considered:

1. Cut the hole with a circle cutter before applying the vinyl to the CP.  This should result in a smooth round hole but it might be challenging to make it exactly the right size and line it up perfectly when installing the vinyl.

2. Apply the vinyl first and then cut the hole in the CP with a forstner bit.  I have one that's the right size and sharp but the chances of damaging the overlay seem high.

Are there other options I haven't thought of?
 - Dave

[PL1]

Are there other options I haven't thought of?

1. Use the optional U-Trak bezel to hide the rough edge.
- You may want to slightly (~1/8"?) countersink the underside of the 3/4" control panel so the top of the U-Trak housing is level with the top of the bezel.
https://www.ultimarc.com/trackballs-and-spinners/trackball-accessories/optional-trim-bezel-for-u-trak/


2. Cut out most of the overlay hole with a knife, leaving a small lip all the way around, then remove the lip using a router flush trim bit for a clean edge.



Scott

[dth930]

Was hoping not to have to use the trim ring.  I just prefer the look without it, but I agree it's a good backup plan.

With the flush cutter, I was concerned that it would grab and tear the vinyl or just push it out of the way because it's not rigid like laminate.  Have you used this method before and had good results?
 - Dave

[PL1]

With the flush cutter, I was concerned that it would grab and tear the vinyl or just push it out of the way because it's not rigid like laminate.  Have you used this method before and had good results?

I haven't, but others have for button and joystick holes.

The bit is so sharp and spinning so fast that it will not grab and tear the vinyl.


Scott

[PL1]

Router trimmed artwork



Nuff said 

There's good advice in that thread about adding a soft layer like adhesive felt strips to the router base to avoid scratching up the art and doing the work outside since the trimmed vinyl bits can stick to whatever they land on -- that's why you want to cut close with the knife and flush trim the smallest amount possible.




Scott

[dth930]

Those are great tips.  I'll give it a test this weekend.  It seems like it should work.
 - Dave