2015 POTD Thread Archive

I machined a bunch of tool holders yesterday and planned on machining the dovetail today. The plan and the new tool holders went into the garbage/scrap pile. I'll get some new stock Monday and try again. Although we strive to, we can't always be perfect.
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jrstech said:
I machined a bunch of tool holders yesterday and planned on machining the dovetail today. The plan and the new tool holders went into the garbage/scrap pile. I'll get some new stock Monday and try again. Although we strive to, we can't always be perfect.
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Why did you ditch the holders? It looks like you made them from aluminium and although not the best material, they would likely have gotten you out of a jam until you machined some from steel.

Paul.
 
den-den said:
Made a worm and gear, my first time to do this. I first made two worms from some 4140 bar (8 tpi acme) and then cut gashes in one and used that to make the gear (delrin plastic). Eventually I want to make a 4th axis for my CNC router, this is the first step. Since this will be powered by a stepper and a computer will handle the math, I did not really care about the ratio for my first attempt (ended up with 130:1). The delrin blank was purposely mounted above center, I am thinking this will allow simple adjustment for backlash/wear.View attachment 104684 View attachment 104685 View attachment 104684 View attachment 104685
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My first lathe was an Emco Maximat V10. Lovely little machines. If it hardened ways I would still have it. Nice work on the gear too!

Paul.
 
They are made of steel. I have a couple inserts out of alignment on the facemill that gives a weird finish to the steel. Look at the pic. The height adjustment threaded hole is where the dovetail is supposed to go!
 
Try this maybe:

Drill the hole where it belongs. Thread in some threaded rod with some stout loctite in the unwanted hole. Machine in your dovetails. Even if you left the hole there,
it wouldn't affect the dovetails.

Also on the dovetail subject: The dovetails need to be pretty accurate, especially if you are using the wedge type. I machine off a tiny amount and test fit in the tool post
until they fit just right. It might take a half dozen fine cuts to get them to fit properly. If they are too wide, they won't hold rigidly.

Sure, I realize one wants them perfect but you already have a lot of time, effort and $ invested. There is no such thing as perfection anyway in my opinion. On the surfaces,
they won't matter and you could work them over on a belt sander or surface grinder and smooth them out a little. Then a little chemical bluing and they would be beautiful.

As a final thought, you could probably get a better finish running the face mill with one tooth if the teeth won't align. That way you could hone it really sharp and feed slowly
at a fast RPM, effectively using your facing tool as a fly cutter.

All things considered, they look pretty good.
 
markknx said:
Dave,
I am looking for a nice log to mount it on. But I am not sure where you see it on a metal stand. Right now it is mounted on a wooden stand, the one it is sitting on in one of the pics. and it has a piece of rubber under it. although I did not do that for the reason you stated. I did it hoping to remove some of the ring. I do see your point of resonance. I also was not familiar with the ash or apple. I still do not know what pic it is sitting on metal in. I know there is one sitting on a milk crate and one on the wooden stand. I will have to surf back a bit and see.
Thanks for the info,
Mark
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You have misread things a little . The place I saw the metal stand was here in the UK where someone who reckoned he was an " Engineer " did his thing.

The traditional blacks smiths anvil found in a lot of the British forges ..
A few indicators you may wish to adapt to scale .
When you set you anvil on the stand you can cut the sides straight make it into a flat topped to a pyramid . The reason for using ash or apple is that once it has been naturally seasoned ( 1 year for each inch of thickness of timber , the stock being kept out of the sun by stacking it under the trees in a nettle filled fruit orchard ) it is a very dense wood that is not prone to splitting like pine or oak . If you use a log style base of a softer or more prone t splitting timber you may put a forged hot steel forge rivetted band round the blcok and shrink it in place like a wagon wheel's iron tyre .
The ideal size for the blacksmiths anvil is that the top of the anvil is going to be level with the top of your crotch or slightly higher . The the base of the anvil is usually as square as the length of the table. saddle . At the top end of the block the size is three inches bigger all round than the base of the anvil so you have wood enough to drive the stakes in .

The anvil is fitted to the block with forged pointed 3/4 square stock forged into inverted " L " stakes that are about 9 inches long ( made from 12 "\ of metal . The points being about 4 inches long that are hammered in as being mid red hot into pre drilled vertical holes so you have a 3 inches wide ledge of wood all round the base of the anvil to put some tools on .

The stakes top ends always face into the ends of the anvil or along the length of the anvil never outwards, the reason being you can wallop on back in should it ever ease and you don't have any edges likely to be sticking out that may rip off your knee caps. If a stake ever does come loose take it out ,heat it to dark red and pour a little water in the hole then knock the hot stake back in the steam generated often reactivates the grip of the wood , causes a bit of rusting that also locks the stake in

If you don't have one , a simple drawn to scale plan on a thin ply wood picture of the anvil base plus the extra " Apron wood " can be made so you can take it with you when sussing out which log to get .... is of great help .
 
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jrstech said:
They are made of steel. I have a couple inserts out of alignment on the facemill that gives a weird finish to the steel. Look at the pic. The height adjustment threaded hole is where the dovetail is supposed to go!
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The old saying read thrice , mark twice & cut once comes to mind .
T'is a pity for they look quality kit .
I wouldn't do as the above post suggests for the thin web of metal that remains may well the weak point that usually fails at that critical point where you have spent hours and hours working not to mention money on turning something important .

Did you do the work off a home made drawing , out of you head or from your minds eye ?

If I were you I'd have a play with them and cut the guide slots in a couple just to see that they fit well and lock in place & everything else looks/works OK as in my book it better to practice on the scrap than do a lot of work and find things need altering
 
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As Cathead has said, those are not really scrap yet. Relocate the threaded hole and then cut the dove-tail. Simple fix. Nice call Cathead.

"Billy G"
 
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