Machining for port work

[Deets066]

394 cylinder?

6100

 

[Deets066]

 

[Deets066]

394 cylinder?

Here’s the 394 cylinder

 

[dustinwilt68]

That's some nice looking work Deets.

 

[srcarr52]

Yikes! Cutting squish and base on a mill is the hard way.

 

[Deets066]

Yikes! Cutting squish and base on a mill is the hard way.

It is, but I just haven’t taken the time to make mandrels and plates to use the lathe. I’ve gotten better at setting up to cut em on the mill

 

[Deets066]

 

[drf256]

It is, but I just haven’t taken the time to make mandrels and plates to use the lathe. I’ve gotten better at setting up to cut em on the mill

One tends to get faster with whatever way is comfortable to them. I swore off cutting bands on a lathe for way too long, then Mastermind told me it was so much more precise and Moparmyway showed me how. It takes me 1/4 the time it did to do it with a mandrel. I’ll never go back.

I’m happy I’ve still got my mandrels though. Every now and again I will use them to clean off a ridge Mr Heineken left behind on the lathe.

 

[hseII]

One tends to get faster with whatever way is comfortable to them. I swore off cutting bands on a lathe for way too long, then Mastermind told me it was so much more precise and Moparmyway showed me how. It takes me 1/4 the time it did to do it with a mandrel. I’ll never go back.

I’m happy I’ve still got my mandrels though. Every now and again I will use them to clean off a ridge Mr Heineken left behind on the lathe.

That darn Dutchman.

 

[GoBigBlue1984]

Takes 10-15 mins to cut a band in the lathe. I couldn’t imagine any other way. But I agree with Al, you gotta do what’s most comfortable to you. Still looks great deeter. End result is the same.

 

[GoBigBlue1984]

I used to cut pop ups in the lathe. I’d use a split bushing .005 oversize and chuck up in a 3 jaw. Anymore I lightly clamp the pistons in a vice and interpolate the pop up in a cnc mill.

 

[Bbintwn]

I would think with the proper fixture it would be just as easy to cut squish and the base on a mill as it is on a lathe.

 

[srcarr52]

View attachment 147378

Careful. You’re assuming the base was square with the bore from the factory.

 

[Deets066]

Careful. You’re assuming the base was square with the bore from the factory.

They’re usually not, but it gets me close to start

 

[Deets066]

 

[GoBigBlue1984]

you bring up a good point Shaun. It’s this very reason that I cut the band first. I know with certainty that after I cut the band it will be square with the bore.

I then indicate my mandrel in (2 places) using a 4 jaw (i like hard plastic or aluminum mandrels). Now I slip my cylinder over the mandrel and when pressure is applied from the live center in the tailstock, the face of my mandrel and the band that I’ve already cut will contact one another.

At this point I’ll cut the base.

 

[Deets066]

you bring up a good point Shaun. It’s this very reason that I cut the band first. I know with certainty that after I cut the band it will be square with the bore.

I then indicate my mandrel in (2 places) using a 4 jaw (i like hard plastic or aluminum mandrels). Now I slip my cylinder over the mandrel and when pressure is applied from the live center in the tailstock, the face of my mandrel and the band that I’ve already cut will contact one another.

At this point I’ll cut the base.

Where are you indicating before you cut the band?

 

[GoBigBlue1984]

I’ll sweep the bore in two places. As close to the base as I can and as close to the band as I can.

 

[Moparmyway]

I’ll sweep the bore in two places. As close to the base as I can and as close to the band as I can.

Yup
This right here is how I do it

 

[srcarr52]

Yup
This right here is how I do it

Same here. I find traming down the bore on either side of the ex port helps you get the cylinder pretty square to the base before you start adjusting the 4 jaw to center it.