Bigger fly cutter

[WobblyHand]

Interesting experiment, but you sure wouldn't want to get anywhere near that thing with a body part. Mike

That's pretty much the case for any fly cutter, isn't it?

 

[Batmanacw]

I think the larger radius inserts will have a better finish, but increased deflection due to higher cutting forces. Do try it out and report back. It's an interesting experiment. There might be a sweet spot.

What's the sample material, 6061? Nice project, I need to make something like this. When you get a chance, can you take pictures of the complete tool out of the mill? I'm missing some details in my mind and a couple of pictures could make them clearer.

Here are your pitchers, Sir!







I ground a new flat to square up the insert.

 

[Batmanacw]

I really wanted to go bigger but 8" is a fair compromise. I have 22.5" of X travel. That leaves me with a window of 14.5" of travel to completely pass over the part in question. Realistically 14". I may need to add another hole for a 7" diameter throw to accommodate longer parts.

 

[Firstram]

That works great!

 

[woodchucker]

I would not have thought the Aluminum would be strong enough. Fly cutting is like hammering... Good to know.

 

[Batmanacw]

I would not have thought the Aluminum would be strong enough. Fly cutting is like hammering... Good to know.

When I decked the head on that engine Saturday it made no sound at all. No hammering. No impact sounds. You could tell it was cutting but no problems in the finish. That was with a Shars 1/2" tool bit fly cutter and a DCGT32.51 insert and the bar sticking way out.

This new fly cutter is far heavier and more rigid. I'm using CCGT21.51 inserts on aluminum.

I'm not taking 0.1" on steel. Never more than 0.010" on aluminum.

 

[pontiac428]

Here is an option to consider, since you are halfway there already. I really like my two point fly cutter. It uses a rouging and finishing cutter, controlled with your feed rate. The balance of two opposing cutters may help your finish and increase your cutting capacity. On a standard knee mill, you can hog some pretty deep cuts, or stagger your cutters tighter for finishing cuts. You can use different tool heights and alternate tool tip radii to achieve the best finish possible.

5" Face mill recommendations

Looking for recommendations for a 5" face mill that I will be using for light cuts resurfacing single cylinder heads which 95% of those would be aluminum. I was thinking something like a round insert sandvik RA200-108R38-19L or maybe something that uses a apkt insert. Most of the head gaskets...

www.hobby-machinist.com

https://www.mscdirect.com/product/details/08253270

 

[RaisedByWolves]

Bumped up to 660 rpm. I am extremely pleased with this result.

View attachment 448516

Try some WD40, gives great finishes on Aluminum.


And oh, you're a mad man.

Its going to be epic when you screw up with that thing. I do this for a living and that is full on 100% larger than I would want to go. Cutting that arc in full will most likely induce chatter.


Impressive collection of tooling in the background.

 

[Batmanacw]

Try some WD40, gives great finishes on Aluminum.


And oh, you're a mad man.

Its going to be epic when you screw up with that thing. I do this for a living and that is full on 100% larger than I would want to go. Cutting that arc in full will most likely induce chatter.


Impressive collection of tooling in the background.

Everyone told me it would flex too much using aluminum. I had to over build it.

We will find out on the chatter. Most engine heads are not solid. I'm hoping it works out. It may never see a full 8" wide contact.

 

[Parlo]

Setting the cutting radius to just over the part width has lots of advantages, I suspect most have been detailed on this forum somewhere.

In your setup it looks like the part is about 2" wide, using the cutter with a 4" radius has the tool cutting for about 8% per revolution. It may be an idea to drill more holes for different cutting radii.