Damaged mill

Hi this afternoon I tightened the quill to cut a slot when I did the casting snapped.

Does this part come off, hope it does, then I could make a new unit and refit. My biggest concern is it part on the main casting/ for the head.

Not really looked too much, when it happened, came in for a coffee

Thats a bummer. Do you have a manual for the mill ? If so the parts list might show if the part is removable.

What mill is it ? Hopefully repairable.

Good luck, regards

I don't think that would clamp up if was part of the main casting? A little more information would help to see what is going on, a picture is worth a thousand words as they say, so two pictures must be worth two thousand words etc. 

Pete

Edited By Pete White on 20/02/2021 19:14:45

Will have a better look tomorrow, but you can see the drilling through the casting is at an angle, left no meat

Pete think you are right, if it was main casting it would not clamp up, I was just so fed up after I just stopped and came in

i don’t have a manual only the instruction came with mill

No possible in this case, but a mate always said I like to go in home after the job has gone well, rather than pushing things and finishing on a disaster.

Yes - there times when something tells you to stop for a brew.

It does look like a separate part.

If it's possible to remove the broken part without having to lift the head off the column (or head+ column from base) I'd be tempted to make the replacement in two parts held together with two pairs of suitably-sized screws rather than as a spring ring. (As I did for a large bench-drill, to support the table so it can be moved round without dropping.)

Or if fitting to a dismantled machine, in the form that has two scalloped sleeves on a screw that passes through one and screws into the other, in a one-piece ring.

(You'd need find a way to support the head safely and machine the new part on the mill, before dismantling it, of course.)

Hi, Rather than dismantle, you could stick weld it! , i had a cast iron quadrant break, so I bought some cast iron welding rods, welded it, then screwed a strip of steel to the outside over the break, ok not pretty but its still ok! Besides its a big strip down to take a milling head off! Make sure there is no grease present and paint! It looks like you could make a steel strap to support the break to the casting? Then paint it cosmetically... Good luck.

Vic, do you have any pictures of the cast welding repair you did? In the past I've done it, and speaking from the point of someone who has at times, welded for a living, thought it incredibly difficult, when I see 'just weld it' comments regarding cast iron, It makes me incredibly curious to see what kind of results the person achieved.

E-mail me with an e-mail address and I will send you some schematics. I have the Chester version but it will be the same thing. I believe the part comes off but only by removing the quill. Its the wrong time of day to go looking

Dennis

Another possible way to save the part would be to grind that area flat and then do some gas brazing to attach steel fittings to do the work of the wonky iron parts that snapped off.

Okay update, back in workshop this morning, took the ring off found broken in two places, see photos.

Good news is if I remove cap at end of quill a new ring would be able to be put back in place.

I am not keen to try and purchase a new cast ring, flexing cast. So what your ideas on material to be used to construct a new ring.

I have alum, or nylon would need to buy in steel

Make a new one out of the aluminium you have; A bit easier to flex than CI.

George.

Aluminium would be fine. If you are making one from scratch you can optimise the design slightly at the same time.

Position the bolt so that it only just clears the diameter of the quill, (might need a longer bolt than you already have) that will give the most direct clamping force.

No need for the quill bore to be in the centre of the 'ring shaped' part, if making it on the lathe the part could look like an eccentric so that there is plenty material for the bolt head and clamping nut to seat on. If you dont already have an indexing handle then just have a clearance hole for a long bolt and have a flat to stop the bolt head revolving. Not sure what the holes and dowel pin are for but obviously you will need to them into account when deciding on the outer profile.

Ian P

Difficult without dimentions ! Thickness 10 -12 mm? Speak to a local laser cutting firm shouldn't cost a fortune and done in steel would be much stronger. or I could flame cut you a blank you can fashion to finish from 10 or 12mm steel. PM me if you wish. Noel.

I broke the cast iron carrier for the depth stop on my RF25 mill. The replacement was made from Aluminium plate. Not cosmetic, but it does the job just as well, possibly better. More metal = more strength ) without a lot of fettling to make it look pretty..

Looks like you have a turning job coming up, followed by some drilling. Either that or some bandsawing.

Catch 22, needs to be milled to shape, but can't be done until the mill has been mended!.

Could you make up a jury rig from some steel strip (say 3 mm ) like a Jubilee clip on steroids so that you can use the mill to finish the part to make the repair.

Could you make the new part by turning, cut it in half and use two bolts to clamp it together? (Drill the mounting holes oversize to allow movement during clamping )

Howard

I would also go for aluminium if I didn't have any steel to hand. It could be made slightly larger diameter without getting in the way. What luck to have the broken part easily removable.

Glad to see that you got the part off ok. As others have said replace it with an Aluminium ring.

regards

Personally I’d go for steel.

Is there room to replace it with a solid ring carrying a proper floating split cotter clamp?

Floating split cotter clamps are basically a pair of cylinders with part of the edge at one end chamfered to engage against the object being held. One is tapped for the clamping bolt and the other has a clearance hole for it. They sit , free floating, in a hole in the carrier ay 90° to the object being clamped. Generally the clearance between bolt shank and object is made as small as practicable to permit decently large clamping flanges. When tightened up the cotters self align and grip so the only scope for movement is the clearance between the cotters and the hole in the carrier. Which is small.

Cotter diameter of 5/8" or 3/4" diameter will be amply sufficient so the carrier can be less than 1" thick.

Clive

+1 on steel. A thinner wall would be desirable for flexibility.