Screw size of Way Locks

[aucran]

Hi, I'm planning on making new way locks for my IH mill, because the current ones catch on just about everything.
I measured them last night, and I think they were M10...does anyone know the pitch? (I forgot to check and I can get the bolts from work today)

Thank you.

[altaic]

Hey man, it's an m10 x 1.5. Hope it's not too late for you to pick it up.

Will

[Cruiser]

Don't just run in an untreated end of a bolt or screw ! It will cut into and deform the contact area of your gib, and it can interfer with the adjustment of the gib later on. So, either grind and buff the end of the bolt till it is ever so slightly convex, or put a slug of very durable plastic or something that won't abraid, blow up from tension, or ware away in to act like a break shoe pad. You will probably be better off using the end of bolt buffed to an almost flat. You will still be able to see where it rides on the gib but it won't do much damage. I took mine out and not using them at all !

[aucran]

Thanks altaic, I had guessed and ordered the wrong kind, but I called to change it. I'll have them by Friday.

And thanks Cruiser, I hadn't thought of that. I'll take your advise and get them to a flat and round the edges off.

This also happens to be the same size of screw that hold old on the jaws of my vise...vise stop is will be this weekend's project

[altaic]

Forget flattening/rounding the bolt-- I would definitely go with dropping a hard plastic or brass slug in there as Cruiser mentioned.

My gibs got marred, and I had ground a slight radius on the tip. The problem is that you will get a tiny deformation if you crank down a bit too much, and next time you line up 1mm from the center of that dent, tightening the screw will cause it to center on the dent and move the table.

So, using the screw directly on the gib requires care as far as how much you crank it down. The softer, non-abrading slug is foolproof.

[aucran]

Heh, alright, I'll see if I can find any brass or plastic tipped screws that size first then. Thanks

If I had a lathe, I'd turn them myself, but then I'd have to start a new thread about how to turn screw threads.

[Cruiser]

Thought !
Using a slug would be and is what it is, but not fool proof !
Selecting the wrong material for the plug could be troublesome !
Consider, Brass or copper and many plastics would deform and swedge into the bore of the hole ! The material must be able to transmit the force applied to the gib without being distorted permanently or distorting the gib !
This is all, of course, relevant to the force being applied, versus the force needed to do the job ! which is to hold and counter the forces involved which want to move the slide within it's slop !
It is true that a dimple is going to be formed into the gib, but, if the gib is set to where it needs to be, and since the gib follows with the side which holds the holding grub, then the dimple is always going to be directly under the grub ! UNTIL it is time to readjust the gib to a new position. This is why I say that the end of the bolt should be ALMOST FLAT, If you were to face the bolt off in a lathe, then polish the end on a stone, by the action of polishing, while trying to hold it straight, it will end up with an ever so slight CONVEX end, it can't be helped, it will be ! And this will do the least amount of distorting of the gib. If the end is even noticeably rounded then it will make a very noticeable indentation to the gib. Just pull gib, its really easy, then dress it and treat with some moly, and reinstall and re adjust when it needs any attention. If it is getting messed up you will see and be able to make necessary changes. The gib is made from the same Grey iron as the rest of many of the machines components and consequently quite durable and forgiving in many ways, yet conversely it is also quite potentially Non forgiving as well. Just go with the lesser of the evils and do the best you can. A slug in the bore under bolt will probably do the same as the bolt if the bolt is modified properly. A slug tho would have slightly more surface area and maybe even an iron slug would do, especially if the iron is beat into a condition of work hardened, before the slug is turned and fitted.

[Cruiser]

One last thought
I noticed on mine that the grub screw pressure had the tendency to cause the gib to form a slight bend. I put mine on the granite and noticed it right away. I only tried mine for a brief period while adjusting gib tensions and thought that a slight pressure from the grub might help with the process, WRONG but thats how we learn some things. What I am saying is, to NOT over use the grub ! Don't use any more pressure than is needed, and don't expect miracles or perfection from its use. It is more feasible, in the long run of things, to learn how to make the slop work to your benefit, between roughing and finishing. The difference between climb and conventional cutting will change whether the cutter will drift into or away from dimension, and FINESSE goes a long way for the rest of it.

[Shev]

It is more feasible, in the long run of things, to learn how to make the slop work to your benefit, between roughing and finishing. The difference between climb and conventional cutting will change whether the cutter will drift into or away from dimension, and FINESSE goes a long way for the rest of it.

Could you elaborate for the newbs?