The machining and fabricating thread (mills/lathes and more here)

[takai]

I was going to post this in the mill/lathe tools thread but it's not really on tools so I figured we may as well have a fabrication specific thread.

Does anyone know or have any ideas on how to bore out a mac strut tube? A mate is wanting to bore his corona struts out by about .030 or so to run Bilstein inverted inserts.
Personally I think the easiest way will be to machine off the existing tube about 50mm above the stub axle and then turn a step into it for locating a new strut tube.

Thoughts?

[Touge Boy]

I agree. There isnt much material to begin with really. not to mention the precision needed to do it. Possible to run a different factory tube at all?

[corknose]

To take off .03 u would just polish it wouldn't bother boring it

[Frak]

Lately I've been messing around cutting threads, my lathe has a quick change gearbox


and I have a thread chasing dial



so basically I can cut any metric thread I want, I think having a reversing motor is a must, also I like using the thread chaser as I can start it any where along the bed.

I started cutting threads using some HSS ground on bench grinder to 60deg(angle for metric threads) you check you angle with one of these

I also like to use this to 'square' up the tool to the part being threaded.

BUT, it can be a bit of a pain grinding up the HSS, so I managed to get one of these



It is cut with a 60deg angle, all you do is grind the top face flat, set the height and thread away, when it gets blunt, you loosen off the capscrew, rotate it a fraction, grind a new flat on top and good to go, the angle is perfect, it makes it so easy.

[takai]

I love my 60deg carbide bits Makes a world of difference for cutting threads, i hate grinding HSS bits too.

Havnt cut any threads with the new lathe yet though.

As for the boring 30thou i would have thought just a polish would do too, although im starting to believe its more like 2-3mm not 20-30thou.

[squeak]

Takai, best way would be to remove the strut housing all together and mill or set up in 4 jaw chuck then machine the base of the strut to fit the correct size tube, this is usually a service done by top quality suspension shops(heaseman in Syd etc), have just send st 165 struts to have dunny door inserts fitted and the cost was pretty good .


peter

[Frak]

I have a vertical milling attachment on my lathe



But I wanted to do some boring and bolt up larger parts, so I just got my hands on this, you remove the original crosslide and this replaces it, you can still put the tool post/compound slide on but it has a heap of t-slots to bolt on angle plates/components.


next on my list is an indexing head

[Tim.duncan]

have you had a chance to make anything on your new toy yet frak?

[Frak]

Yep mainly tooling type things, but have made some fancy alloy wheel caps and alloy rim locaters.

[takai]

On my little walk back from Car Torque just then, i was thinking about making up some tool holders, really similar to the QCTP units but fitting into the standard tool post.

High on the agenda would be a U shaped one for my general cutting bits, this would be a simple U shape with a side and base of 4mm (need 4mm of spacer below) and the other side of 6-8mm so i can tap it and put some M6 capscrews through to just hold it in place.
The next one would be a piece of alu with a hole drilled in it for the boring bar, again a pretty simple one with just a couple of grubscrews holding it in place. But also spaced correctly vertically and with a nice flat edge that i can line up with the back of the toolpost so i know its pretty much parallel.

Anyone made stuff like that that i can look at for inspiration?