worktop radius

[jonny round boy]

Hi thanks jonny round boy for your reply what you have described to me is what i have been trying to do, making a separate jig and then routering from the top this time if that’s correct,could you tell me the correct way to find the radius of the internal corner this is what i must have got wrong (its been a long day)thanks again for your help

There isn't really a 'correct way'. Just measure it as best you can. If you're unsure, you can guesstimate it, then use a pair of compasses to draw your guessed radius on a piece of card, cut it out, and offer it up. If it's not right, then just keep repeating until the card fits the radius.

[PJK]

Or google to door supplier and find the tech sheet for the door

[doonjwaft]

Yeah i have spoken to the company (ultima) kitchens to see if they could supply a jig but they cant i can get the curve right by useing the circle jig its when i try and transfer the shape to create a new jig so i can router from above it goes out am i being silly trying to get it mm perfect ?

[snezza]

Yeah i have spoken to the company (ultima) kitchens to see if they could supply a jig but they cant i can get the curve right by useing the circle jig its when i try and transfer the shape to create a new jig so i can router from above it goes out am i being silly trying to get it mm perfect ?

What is the internal radius of the cabinet? If you can tell us that, then im sure we can tell you the radius of the jig you will need to make taking into account the size of the cutter you are planning on using and the guide bush in your router.

I make and have made jigs regularly, so will try to help as much as I can.

[doonjwaft]

I think the radius is 160mm thats with 40 over hang from the carcass, guide bush is 30mm with 12.7mm cutter thanks very much for your help

[snezza]

I think the radius is 160mm thats with 40 over hang from the carcass, guide bush is 30mm with 12.7mm cutter thanks very much for your help

You think the radius of the finished worktop needs to be 160mm....? I have to say, that sounds a tight radius for an Ultima internal radius base corner unit.

Even so, if the finished size of worktop is indeed 160mm radius, then you will need to cut a radius on your jig of 168.65mm if you are using a 12.7mm dia cutter and a 30mm dia guide bush.

Using Jonny Round Boy's jig, set it up to cut the above mentioned size, but make sure you measure to the furthest edge of the cutter from the centre of your pivot point.

[doonjwaft]

Yeah i have probly got the radius wrong, struggling to work it out ,am i wright in thinking i cut a template using jonny round boys jig then router another piece of mdf running the guide bush along that one sorry for all the questions

[snezza]

Yeah i have probly got the radius wrong, struggling to work it out ,am i wright in thinking i cut a template using jonny round boys jig then router another piece of mdf running the guide bush along that one sorry for all the questions

Im afraid i am nowhere near as adept with Sketchbook as JRB is, so I cant post any pictures as he did.

If I was making the jig you require, I would ensure the mdf sheet was at least 600mm x 600mm square. Find your pivot point, set up JRB's jig to 168.65mm and rout the radius. You will then need to cut the jig out accurately ensuring you have a lead in and lead out of the radius at 90 degrees to each other. This will allow you to feed in and out with your router and guide bush either end of the curve you will have created.

[doonjwaft]

OK thanks very much for all of this i will give it another go tommorrow one last thing am i right In thinking there will not be any worktop to pivot off at that corner because the worktop isnt wide enough?