Help me build a jig for repetative miter cuts?

[dmworking247]

I'm potentially going to be building a LOT of control panel boxes. The beauty of the material I'm using is that its preprimed, prebevelled architrave.

The thing thats costing me the most time however is doing the 45' miter cuts.

I have:

• A compound mitre saw (but its currently a rough blade that I don't want to keep changing, and I also dont have a spare A$100 for a 100-tooth blade).
• A jigsaw (difficult to get EXACTLY 45' especially if I have to keep re-setting the tool to its regular 90'), and its also difficult to cut these panels in a perfect straight line without a jig/guide.
• A router (trying to figure out a way that I could build a jig using a patern bit to make perfect repeatable miter cuts).

Here's an example of the 'boxes' I'm trying to make repeatedly. Note the mitre joins in each corner. The MDF is roughly 1/2" thick and 2 2/3" tall (I'm hopeless with imperial).



I'd like to be able to cut perfect 45' miter cuts for two 'set' lengths of MDF with a minimum of setup/configuration. Can anybody suggest the right tool/how I'd build a jig to make life easier?

[nuka1195]

1. miter saw with a stop block
2. router mounted in a table with a 45 degree bit and a miter gauge.

[dmworking247]

Ah! For some reason I had never thought about a 45' bit for the router (duh!). Thats given me something to think about, thanks!

[Franco B]

I was racking my brains trying to think up a way for you cut them with a router, I had never thought about a 45 degree bit either! Good plan

[Twinpanther]

And if you wanna be fancy.

45° Lock Miter Bit

[Blanka]

And if you wanna be fancy.

45° Lock Miter Bit

But with a lock bit, it won't work on the rounded edges. The joint won't be OK.

[nuka1195]

it should work fine, just round after putting it together.

[Blanka]

it should work fine, just round after putting it together.

The beauty of the material I'm using is that its preprimed, prebevelled architrave.

 

[nuka1195]

i still don't see an issue, plus glue ups with that router bit should be easier.

[Blanka]

If it is pre-bevelled, you cannot make nice connections with the lock bit!
This is what will happen:

[Blanka]

This is probably easiest for quick perfect 45 degree mitters (with the not shown angle-guide attached, or by turning the table in 45 degrees)
A table saw is also perfect for it, but it is harder to get the length of the parts perfect to the last 1/5th mm.
Guess I was half the time behind this machine when making the graduation town plan models 

[shardian]

Your Miter saw is the absolute best option for this. All you need is to rig up a stop block. Set up the block once, adjust the saw once, then bang out 100 pieces in 15 minutes. It is worth investing in a decent blade.