PROBLEM, HOW TO - open up an inaccessible hole in 10mm s/s?

Scotty_Tradewind

Scotty_Tradewind

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I have a new inner forestay to be fitted, going in to sit a short way behind the forestay itself which is out on a short bowspit.

All is complete except that I have to open up the attachment hole in the 10mm stainless steel 'separator' between the two anchor rollers to fit the

10mm pin. I need to open up the hole by 1mm.

The gap I have to get a drill or grinder into is extremely narrow and I've been looking at mini right angled grinders with a pencil grinding stone etc.

The pencil stone could be entered into the s/s hole before being connected to the tool itself. I've looked at Dremel with an angle attachement and

some mini air angled grinders, but they are a fraction too large to get into the space required.

Any ideas please?

S.
 
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A tapered grinder bit in a drill should work, just don't put it in so far that it jams.

I have a Dremel with a right angle attachment, it would be hard pressed with stainless but if treated with respect and going slowly it should do it.

Another option might be to simply use a drill with a normal drill bit from the outside, open up the holes - if there's sufficient ' meat ' on the fittings - then if necessary use a slightly larger drop nose pin ?

Or a carbide round file with elbow grease...
 
A few thoughts, and hard to know without seeing a picture:

1, Buy a series of reamers (off ebay, £6 each) at 9.3, 9.6, then 10.1 or whatever. Shorten the reamers to only 50mm long or whatever, with a grinder. Then use them progressively to open the 9mm hole up to 10, using a spanner to turn the reamer.

2. Will the nice Makita 90 degree headed battery drill fit in, using again a shortened drill bit?

3. Drill a 10mm hole thru the outer plate of one side of the anchor roller fabrication - a hole that would ultimately be redundant but would allow you to get a big powerful drill involved and fed to the centre hole that you want to enlarge. And use the right drill bit material, obviously

4. I don't like this idea at all but you could make an adapter device consisting of 2 small plates say 60mm x 25 x 5 ish with a 9 hole one end and a 10 hole the other end. Then use this pair as an adaptor, using a 9 pin at bottom and 10 pin at top. But I don't really like that and you probably don't either!
 
I'm guessing that it is the outer cheek plates of your double roller that is giving the access problems. If access between is not feasible, you could perhaps drill through the outer plate and through to the centerplate; or if 10mm is not really required, could you have it turned down to 9mm?
 
Drilling through the outer plate then the centre hole sounds the obvious.

What I omitted to say was that the large tube of the bow spit gets in the way of the access to that. :(

I've added a photo and video which may give an idea of the problem.... apologies for its length.

http://s725.photobucket.com/user/johnscottorn/media/IMG_4036.jpg.html?sort=3&o=68

http://s725.photobucket.com/user/jo...shelteredbuttherewasweed.mp4.html?sort=3&o=21

A Makita head and chuck wont fit. I've seen an air tool on an American site that might do it but it costs more than the boats worth.

Reamers ground down might do in.... what are they like with s/s ? Can you buy exceptionally hard ones?

If I had a hard ended drill bit that had a very long shank it miught be doable with an electric drill???

thanks for your ideas so far,

S.
 
You can get tapered reamers, but its going to be hard work and they will be prone to breaking. Did you get anywhere with looking at a having a new fitting made up with a smaller pin, It might work out cheaper in the end.
j
 
My first idea is quite bodgy:
Find a selection of old taps (the thread cutting sort!) and wind in anything less than or up to 10mm that removes metal.
If you have a random selection of BSF, metric and so forth, you might loses most of the unwanted metal.
Finish with a file, possibly one you've ground some teeth off so as not to cut where you don't want to...
Maybe you can live with a thread?

My second idea is a bit less sordid
If you think a long shank drill will work, a 10mm masonry bit might do it.
You can buy these quite long from Screwfix etc.
you might usefully reshape the carbide inserts to be a bit more like a glass/ceramic drill, which works well on stainless?

Practice on something less critical first?
 
yes a flexible drive and chuck would be able to access the outer holes but I think the closeness of the cheeks to the middle plate would prevent me getting to the hole I want to open up.

I thought about rat tailed files....... a long thought!!! It may come to trying that. Leather gloves etc.
Maybe I could set up a couple of twists of leather lace to each end of the shortened file and make up some form of shaft to propel it around ???

The smaller pin may be a way to go although I don't want to reduce the shear strength of the pin ideally.


Taps I do have..... it may just get me on my way, although they may be too long... I could grind off the ends though .....??
S.
 
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PlankWalker said:
I like Sailorman's idea of a broken round file, held between two mole grips it won't take long to file it down.

Plank
Click to expand...
Maybe you have more patience than me. I think it's a near impossible job to file the hole in plate that thick a millimeter larger even with decent access.

Unless the stay is already made to length, I'd put another link in the system - a long shackle or a custom made pair of plates bolted through the existing hole to give you an attachment point above the bow fitting. bit of a bodge, but I think it could be done fairly neatly and with little loss of strength. If that can't be done then I think your best bet is to replace the pin with a bolt that fits through the existing hole.
 
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sailorman said:
break a rat tail file ( carefully with all the ppe you can muster) then spend an hr in & out through the existing hole
Click to expand...

+1

When I was an apprentice, stainless steel,(inox,) was one of those materials that always caused problems for newbies, (welding, drilling.... etc.) Once you learn the tricks, techniques and limitations, it is not that bad :ambivalence:

In this case, (drilling,) the real problem is not access, but the fact that inox is very hard and does not machine easily. In order to successfully drill, (or machine,) SS, you need a very, very slow cutting speed. Even grinding can be problematic if not done with an appropriate stone or grinder. Often, for a one off grind, you can get away with using a more general purpose stone, but I doubt this would be the case here. These small 10mm buffing stones are just not designed for this type of work and will probably shred.

From bitter experience, this is one of those situations where you just have to recognize that adopting the most unappealing solution from the outset will be both quicker, easier and involve a lot less heartache.

For cutting the file, great care must be taken: Use an angle grinder to circumscribe a notch at the the appropriate length and then well wrap the file with a towel or old boiler-suit. Put it in a vice, (gripping just below the notch,) and hit it gently with a hammer.

Clasp your new tool in pair of pliers or mole grips and work it as previously suggested. You may be able to set up a fulcrum to get a kind of rocking motion. Remember to check regularly for size and shape.

To take your mind off the tedium, think of PoW's digging tunnels with a spoon :disgust:
 
Scotty_Tradewind said:
.............

The smaller pin may be a way to go although I don't want to reduce the shear strength of the pin ideally.

............

Taps I do have..... it may just get me on my way, although they may be too long... I could grind off the ends though .....??
S.
Click to expand...

Think very carefully before using a smaller pin, even if it worked, (and that is a big if,) it would invalidate any warranty and probably cause insurance problems.

Tapping the hole, is one of those appealing ideas that in the end would probably create more work than it saved. Also, you start running into problems with residual sharp edges that not only cut into the pin, but create point loads that the pin was never designed to take.

Again, from experience, if you just bite the bullet and work with the file, you will be amazed at how quickly you get the pin into the hole. After all, it is only a millimetre.


Edit:
After some more thought on how I would do this:

If you have any blacksmithing skills and access to a good oxyacetylene "burner", (a simple welding torch is not powerful enough.) Then rather than cutting the file, put a bend in it.

The trick here is that it needs to be bright red over at least a quarter up-to about half the circumference of the bend radius. Once you have made the bend, quench it by plunging it into a bucket of water, pull it out for a few seconds, then drop it back in and leave it to cool. Don't worry about the quality of the tempering, you would never get it right, basically you are just trying to maintain the hardness of cutting teeth, while not having the bend/shank so hard that it shatters and explodes.

This type of tooling is done quite often in general purpose engineering workshops and can be a lot easier to work with than trying to hold a stub of file in a pair of mole grips.
 
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Before cutting/filling anything, if access is that tight have you checked that you can actually get the pin into the gap alongside the terminal to fit the thing?
 
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