Milling countersunk slot

[scholar]

It's a long story, but we have some complicated projection hinges (all to do with the arched window and the annoying stormproof casements which was nothing to do with me btw). Here is one:



The hinges actually work fine, but were not all installed very well (I did design them to solve a problem, but did not fit them). The fit of quite a few of these hinges needs to be adjusted by bringing the casement tighter in to the frame. This might be achieved by adjusting the hanging of the casement on the cranked hinge, but it will be better to avoid messing with those screws as getting new fixings a few mm away will be tricky (and we don't want them falling out!). I think the better solution and allowing for adjustability when refitting, will be to move the whole hinge in towards the frame. The four screw fixings into the wall reveal cannot be easily moved, so I think making the countersunk holes a countersunk slot would be best.

So the question is how best to machine the slot if I do not have a milling machine (which I don't, although would like, but cannot justify going out to buy one for this job). The screws are 5mm/No 10 and I guess the max lengthening of the slot will be say 6mm. The material is 3mm stainless steel. I have:
- a decent set of HSS countersink bits
- whilst I have a pillar drill at home, this will be 200 miles away, so will be limited to my drill press stand with a mains drill
- I don't mind buying a compound vice or some such if the rest of the set up is going to work.

Ideally I would just take the whole lot off to an engineering shop and get it done, but I am going to have to fettle the windows one by one, so practically it has to be done on site.

My current thinking is to try filing the hole into an elongated hole, then machine the countersinking. Obviously, I am concerned about whether the drill and drill press will withstand the lateral force.

Any views on whether this is doomed to failure?

cheers

 

[adidat]

blimey I don't envy you! I have a drill press its okay, but there is some play in it, so it would probably just move around rather than countersinking it nicely.

What about a die grinder? You can get bits for them to match the screw head angle, still a tricky job but I Think your proposed idea is a non starter.

Adidat

 

[graduate_owner]

Thinking of drilling new holes a few mm away from the old ones, could you drill a hole and glue in some dowel. Then you can get a fresh start on the positioning.

K

 

[scholar]

Thanks chaps

particularly

I Think your proposed idea is a non starter.

Adidat

That is what I am worried about. Oh, I didn't mention there are thirty hinges x 4 wall fixing holes = 120 slots...! Ok, many of them are not far out, so will only need a few mm of adjustment, but even so, I think I share your reticence. I might try an experiment with a bit of scrap and see how it goes.

I keep looking at milling machines, but I suspect it will need a decent sized one.

Thinking of drilling new holes a few mm away from the old ones, could you drill a hole and glue in some dowel. Then you can get a fresh start on the positioning.

K

If I fiddle with the positions on the wood, yes, that is the right way I guess.

Blinking builder's carpenter should have got it right in the first place.

cheers

 

[Wildman]

dremel grinder or similar should sort a few mm or even a round file

 

[porker]

dremel grinder or similar should sort a few mm or even a round file

got to agree. I think a dremel tool would be the best bet. I think you would struggle with a drill press as a mill. I tried that once (before I got my mill) and the chuck dropped off the taper. They aren't designed for side loads.

 

[adidat]

Maybe a bit hard nosed but if you where just making them, and not fitting them. Wouldn't it be best to let them sort it. If I bought a large sliding door online, and had 3 unskilled labourers install it. I could hardly go back to the company and say this door doesn't work? Or have them brought back and fiddle with them in the comfort of your workshop.

The large distance would certainly put me off unless I was at fault or heavily compensated.

Adidat

 

[scholar]

Maybe a bit hard nosed but if you where just making them, and not fitting them. Wouldn't it be best to let them sort it. If I bought a large sliding door online, and had 3 unskilled labourers install it. I could hardly go back to the company and say this door doesn't work? Or have them brought back and fiddle with them in the comfort of your workshop.

The large distance would certainly put me off unless I was at fault or heavily compensated.

Adidat

It's a long story Adidat - it is a family place and the building work was done quite a while ago. I designed the hinges to overcome the issue of an arched window fouling the head of the wall (an issue the architect should have spotted before the windows were designed and made (all before I got involved). The window fitting was some way down the list of "issues" and I am steadily working through the list myself.

I think the Dremel suggestion is a good one so many thanks for all the helpful input. I guess I will try and file the central hole into a slot then fashion the countersink with a suitable grinding head. (I needed an excuse to buy a Dremel or similar, so a trip to Axminster is in prospect.)

Cheers

 

[seaco]

As far as milling in a drill press well it depends on how big it is I have done this before I got my milling machine, I used a proper milling four flute cutter very light passes and use a jig to hold the hinge square don't even think about holding the hinge by hand, it's a shame your so far away...

Do not get me wrong it's not really the way to go but needs must, another way I've thought of but never tried how about a rat tail file in the drill chuck then through a small hole drilled in some MDF pushed through so just a little of the file can be seen to reduce pressure on the file.

 

[Setch]

I would be far more inclined to adjust the hole in the timber than in the hinge. If you're only moving a small distance I favour making the new hole with a bradawl, this will usually push the wood fibres together around the new hole, forcing the old hole shut.

This can be done without removing the hinges, where as modifying the hinges requires complete removal of each hinge. In addition, slotted fixings will be more inclined to slip or creep, as the countersunk screw doesn't fit (and thus constrain) the hole in both axis.

 

[Inspector]

A Dremel is going to be woefully inadequate. If you are going to grind the slots you need a die grinder like this http://www.toolstop.co.uk/makita-gd0600 ... nder-p3018 with carbide rotary files / burrs like these http://www.aetools.co.uk/products-abras ... hss-41.php . Know too that SS work hardens if you work it at too high a speed and not enough pressure and will destroy HHS burrs and even carbide at times.

Pete

 

[Zeddedhed]

I would go for new holes in the timber casement. Either use one of these http://www.axminster.co.uk/veritas-plugger-476056 or drill 5mm holes and glue in some hardwood dowels. Once dry chisel them flush and off you go.

I recently had to re-hang a hotel's worth of doors that had been hung too far out from the linings by a chimp of a so-called chippie - a similar problem and this is what I did. Worked fine even though the doors were heavy fire doors.

 

[AndyT]

I think that while elongating the slots might be possible, you would struggle to lengthen the countersinking.
It's far more practical to shift the holes in the wood. I did this at the weekend on some ill-fitting cupboard doors and it's easy - knock in some bits of matchstick, make the new hole with a bradawl, re-insert screw. I could move a hole as little as 2mm along the frame.
For your more critical job, drilling the screw holes to a known size and gluing in dowel, as Zeddedhed said, would be quick and secure. It will also be invisible when done, unlike the slots.

 

[scholar]

If nothing else, all of the comments and suggestions (all very much appreciated btw), confirm I am right to be worried about this.

A Dremel is going to be woefully inadequate. If you are going to grind the slots you need a die grinder like this http://www.toolstop.co.uk/makita-gd0600 ... nder-p3018 with carbide rotary files / burrs like these http://www.aetools.co.uk/products-abras ... hss-41.php . Know too that SS work hardens if you work it at too high a speed and not enough pressure and will destroy HHS burrs and even carbide at times.

Pete

I broadly reached this conclusion last night looking at Dremel type things, so thanks for the links.

I agree with the various comments that it will be easier to shift the fixings in the wooden casement - it potentially has other problems with how the hinge crank sits with the stormproof lip on the casement, but I will have another look at this when I am on site.

So, just for completeness, if I did have a milling machine :-k , what are people's views on achieving the machining? Would that be a straightforward job for a milling machine (with what bit?) or is it still a tricky task?

Cheers

 

[Inspector]

You can mill the slot easily enough keeping in mind the work hardening if you let the tool dwell. The bit would be carbide 4 or more flutes along these lines, http://www.cutwel.co.uk/milling/milling ... 515-series or this http://www.sgstool.com/product.aspx?gro ... edPanels21 You will need to lubricate, preferably flood (continuous stream), while machining. You will still have a bear of a time with the countersink and finding a bit for that.

I too think you should plug the holes in the wood and reposition.

Pete

 

[Zeddedhed]

Just in case this hasn't already been pointed out, anything that's fixed through a slot rather than a hole can move, so you may end up back where you started after a load of milling and countersinking.

 

[graduate_owner]

It sounds to me like you really need a good excuse to go out and buy a milling machine to play with, but
I think this is not really a convincing excuse in this case. Drill and plug the wood, then re fit the hinges. Then, go and buy yourself a milling machine as a special present for completing all that work. I have found loads of uses for mine and have never regretted buying it, although it was second hand so not such a great outlay. Be aware you can spend an AWFUL lot on extras though.

K

 

[scholar]

Drill and plug the wood, then re fit the hinges.

K

I too think you should plug the holes in the wood and reposition.

Pete

OK, I hear yah all.. It is pretty unanimous regarding the machining. It was an enlightening discussion for me.

I need to look at each window one by one and work out the solution - where it really is only a mm I may have a go at grinding and/or I might be able to reposition the rawlplug in the wall. For the few extreme ones, I might look at chopping out and replacing the fixings with some resin or something (knowing that carpenter, they are probably only held in with chewing gum and roll up cigarette butts anyway).

Don't worry, I will find that reason for a milling machine!

Cheers

 

[graduate_owner]

Hey Scholar - why not get a metalworking lathe as well while you are out buying your milling machine? Convince yourself you have earned it.

K

 

[chipmunk]

Hi Scholar,
This is just a suggestion but from looking at your brackets, 4 screws into the wall seems a over-kill to me. I think that you could probably get away with one, or two at the most, IMHO.

So, if it helps when moving the brackets slightly why not drill a centre-hole, or two, into the wall-plate and use these new holes to mount the bracket onto the wall?

If you think the empty screw holes look too bad then drill the old four holes in the masonry over-size, plug with some filler of your choice, redrill and plug and put the now decorative, but structurally unnecessary, screws into this?

No need for a milling machine or lathe though
...but you'll have earned one by the time you're finished

HTH
Jon