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Tiger
5th Dec 2005, 12:48 PM
Hey all,


I have a Hare and Forbes Bench lathe AL 50 series. I have borrowed a vertical slide attachment for milling and attempted to mill some metal. There is a fair bit of chatter and the work is a little rough. What I am attempting to do is to make some v blocks for drilling metal etc, it seems like a good exercise. What I'd like to know am I wasting my time with a vertical milling attachment and should I just save up for a mini-mill which you can get for $850 at Hare and Forbes. Has anyone out there been successful with a lathe of this type and a vertical slide attachment?

By the way, how does one make a v cut using just an end mill on either a lathe or a milling machine (does the vice hold it properly?).

Rebus
5th Dec 2005, 07:50 PM
Greetings,

I have a H&F milling attachment which I use on my AL330 with some success (if I do say so myself). I have found that there are several rules worth following.

* Clamp the two halves of the milling slide together. There is quite a bit of slop between the fixed half and the sliding (workpiece) section. I use a 150mm record G clamp. This is really essential.

* Always arrange the work and milling cutter so that the force upon the work is directed down towards the bed of the lathe. Lathes are designed to accept precisely this type of load. If the cutter is arranged in such a way that it lifts the workpiece off the bed, chatter is introduced.

* Use light passes.

Personally, I have had only limited success using standard milling cutters. However, I have found that a properly set up fly cutter can work extremely well. The main problem is it's SLOW. :mad:

A fly cutter can be set up using a piece of (say) 6mm or 1/4 inch tool steel which has been ground like a normal lathe tool bit. The trick is to attach the tool steel to your faceplate so that it prescribes an arc which comes into contact with the workpiece as it is fed past the flycutter.

You can make a simple holder from (say) a piece of 19mm steel around 30mm long. Drill and tap a hole parallel to the axis (along the centre) of the cylinder so that it will accept a bolt passed through a slot in the faceplate. The bolt then fixes your holder at the required radius. Drill another hole of sufficient diameter to allow the tool bit to pass through, this time at an angle (say 45 deg.) to the axis. Drill and tap a hole at right angles to this hole to accept a small set screw which is used to fix your tool bit in position.

You then have a simple fly cutter which when correctly set up will put a very clean face on any piece.

When fly cutting remember to ensure that the tool bit meets the work correctly positioned to ensure that you have the correct rake and clearance. Take note of the usual rules for work speed past the tool.

Hope this helps.

BTW without giving away your personal details, is your Blackburn the Melbourne Blackburn ?

Regards,

Tiger
5th Dec 2005, 11:56 PM
Hi Rebus,

Thanks for the advice. I'd like to chat further with you especially about how you tackle grooves and slots on your lathe. I am from Blackburn in Melbourne, which part of Melbourne are you from?

Ozfox
27th Jan 2008, 04:12 PM
Hi Rebus and Tiger,

I stumbled upon your discussion while I was looking for a small business, or individual, who has access, or owns, a small, accurate Milling Machine. I need some prototypes for an invention to be produced out of ABS plastic (fairly urgently) and am prepared to pay, of course.

Interested to chat about it? Please drop me a line at [email protected].
(I live at Bundoora, in Melbourne).

Joseph Tefaye

neksmerj
27th Jan 2008, 11:49 PM
Hi Ozfox,

If you want some really accurate CNC milling/machining done, contact Bruce Sansome at Natex (Aust) Engineering P/L in Campbellfield on 9308 0855.

His work is first class and at reasonable rates. :2tsup:

I don't have a vested interest in the company, :no: just seen examples of his work as per my design.

Ken

Outsider
29th Jan 2008, 12:16 PM
Hi Guys,

Rebus where's the Picture.

I am in the process of making a Milling attachment reom flat steel bar from a 1958 magazine.

I will show some pics as time progresses.

I have totally redrawn the plans in Metric but would not like anyone to copy my mistakes, so will wait till it is proven.

malb
29th Jan 2008, 04:05 PM
By the way, how does one make a v cut using just an end mill on either a lathe or a milling machine (does the vice hold it properly?).

The traditional method would have been a shaper like this http://cgi.ebay.com.au/SHAPER-LOCK-TOOLS-240-VOLT_W0QQitemZ150209163944QQihZ005QQcategoryZ105827QQssPageNameZWDVWQQrdZ1QQcmdZViewItembut a more current method would be a milling machine. The secret ingredient with a mill would be a tilting vice that could be set to 45 deg to hold the job so that the cutter tip will cut one face of a V, and the other face when the work piece is reversed.

A vertical slide attachment is a big compromise in rigidity in comparison to a true mill or even a column and mill head mounted onto the lathe bed, as the cutter thrust is directed to the saddle and will try to tilt it. This invariabley will try to raise the saddle at the chuck end and reduce the bearing area to a minimum.

Chatter is a result of trying to tilt the saddle on the bed, any slack in the crossslide and VC ways, and any flex in the VC mounting system.

From memory, Rebus' AL330 is a much more substantial machine, and can cope by using fiddles such as clamping the column. Try his suggestions, but I suspect that you will be limited to squaring up the block with very light cuts.

GraemeL
2nd Feb 2008, 11:29 PM
To: Rebus,


* Clamp the two halves of the milling slide together. There is quite a bit of slop between the fixed half and the sliding (workpiece) section. I use a 150mm record G clamp. This is really essential.

...which means that it would be a whole lot cheaper to clamp the work onto a homemade angle plate - or am I missing something?
:doh: