Can you make a curved slot using a DRO?

[Suzuki4evr]

Thanks gents,for all the advice, but I must give credit to Mr. Whoopi because I went with his DRO 360hole idea and it worked quite well. I knew I could use the bolt circle function but did not think of using 360 holes as the number of holes, so thank you Mr.Whoopi for pointing me in the right direction. The mistake I made was trying to drill holes on an arc I made with the calliper and I was bit out so the slot looks a bit rough and out of alignment with the arc on one side, bit it will work for the requirement. I still need to do the bottom plate and tgen I will get it right.

An arc has been made......it won't float but it will let a bolt slide

The pic below shows the rough side on the one side.


Thanks everyone.
Michael

 

[PaulJ1950]

The better DRO's have an inbuilt program for milling arcs, both in the horizontal and vertical direction (if you have a 3 axis DRO). The readout indicates the position of each X and Y (or Z) that you move the table for each point around the arc.
Paul

 

[Suzuki4evr]

The better DRO's have an inbuilt program for milling arcs, both in the horizontal and vertical direction (if you have a 3 axis DRO). The readout indicates the position of each X and Y (or Z) that you move the table for each point around the arc.
Paul

My DRO does have the arc function but I thik I might have programmed it incorrectly when I tried it.

 

[projectnut]

+1 on BladesIIB comment. Not much sweep there. I'd use a French curve or freehand a line with Dykem and mill to the line.

Bruce

A French Curve? You're showing your age. I haven't heard that term in 30 years. However the truth be known I do have a couple in the drawer under the drawing board.

 

[rwm]

My DRO is so complicated I would rather use an outside program. It is just an invitation to make an input error.
I just added the LMS calculator to my phone
Robert

 

[hman]

I used the bolt circle (aka PCD) function on my mill's DRO to cut a pretty large circle out of a 3/8" aluminum plate. I started by calculating the circumference and dividing by 1/4" to get the number of holes. Set up the DRO to make a circle with half that number of holes (spaced 1/4" apart). Then I re-programmed the DRO to make the same diameter circle with holes halfway between the first set. By spacing the holes that way, I was always drilling into a symmetrical web on second pass - so little or no tendency for the drill bit to wander off sideways. I'm not sure, but it's quite probable that I used a 1/4" center cutting end mill to make the second pass holes.

Once you've done something like that for the basic slot, you can either proceed with the "etch-a-sketch" method, or else program additional circles (arcs?) with finer and finer resolution. In my case, once I had the rough-edged hole cut out, I was able to finish cut with a boring head.

 

[Suzuki4evr]

I used the bolt circle (aka PCD) function on my mill's DRO to cut a pretty large circle out of a 3/8" aluminum plate. I started by calculating the circumference and dividing by 1/4" to get the number of holes. Set up the DRO to make a circle with half that number of holes (spaced 1/4" apart). Then I re-programmed the DRO to make the same diameter circle with holes halfway between the first set. By spacing the holes that way, I was always drilling into a symmetrical web on second pass - so little or no tendency for the drill bit to wander off sideways. I'm not sure, but it's quite probable that I used a 1/4" center cutting end mill to make the second pass holes.

Once you've done something like that for the basic slot, you can either proceed with the "etch-a-sketch" method, or else program additional circles (arcs?) with finer and finer resolution. In my case, once I had the rough-edged hole cut out, I was able to finish cut with a boring head.

Thank you. I will keep this in mind for the next time I need to make an arc slot.

 

[Flyinfool]

Do a rough cut first using a saw, cutting torch, drilling holes, or what ever you have. For the clean up pass you can also program the DRO for holes every 1/32 or 1/16 (or finer if you need it) and then use an endmill that is set at full depth and leave it there The bigger the endmill diameter the better and the fewer positions you will need. Always move the axis first that will take the cutter away from the part then move the axis that brings it back in You can get surprisingly good results.

 

[Larry$]

The better DRO's have an inbuilt program for milling arcs, both in the horizontal and vertical direction (if you have a 3 axis DRO). The readout indicates the position of each X and Y (or Z) that you move the table for each point around the arc.
Paul

My DRO has that function. I have to keep the instructions close at hand when using any of the "special" functions. But they do work well.