Marterial Opinions

[The Metal Butcher]

aagh, that sucks. Maybe find a decent chunk on eBay? I have better luck there lately, for odd off-cuts. Sometimes you can even find free shipping.
(I have seen threads milled so poorly that you can see the individual facets of the cuts with the bare eyeball....)

I thought that was standard lol. Every single thread just about has had that quality.

Lynn, I appreciate the offer. I will need something big enough to clean up to 100mm/ 3.937in.

[nickel-city-fab]

I thought that was standard lol. Every single thread just about has had that quality.

Lynn, I appreciate the offer. I will need something big enough to clean up to 100mm/ 3.937in.

I wonder if your part could have been saved by running a tap thru with a slightly larger -GH size? Or am I not understanding correctly? (I've done that trick before where you pack the flutes with an old kleenex, and it does work)

Wait, that makes no sense. The spigot is a close fit, right? So it should be concentric? When I made my ER adapter, I turned the internal taper in situ, guaranteeing zip runout. It doesn't hurt an ER to take a skim cut in the ID taper and trim the threaded nose a bit shorter if need be.

Quality and value has gone down the crapper in recent decades, sad to say. I know that decent product can be had, you just have to look for it a bit more nowadays.

[J Tiers]

Thread milling is bad? The process used to get better quality threads? Are we talking different things here?

Something does not add up.

What "register" are you talking about?

[nickel-city-fab]

Thread milling is bad? The process used to get better quality threads? Are we talking different things here?

Something does not add up.

What "register" are you talking about?

I think he means the backside of an ER chuck adapter. I've never seen that thread milling itself is bad, but it can be done badly. So IO was wondering about correcting the situation with a tap.

[The Metal Butcher]

Spigot was a tight fit, too tight. I turned it .015 over, like I do with all of my faceplates. Guess that'll do it. I don't believe in centering off the spigot/register anyway.

[Dave C]

Well it's hard to say. I often think up projects with what I've got haha. I do need to design a tailstock chuck sometime. Tempting to make it Mt5 for my Daewoo, but then I need to make a new quill for my Sidney. I guess I ought to design something first and see what I need.



Me too. It makes a mess, but so long as I have more CI work coming, I don't feel so bad about not cleaing up.



Not really. The only 1 are kinda ****heads. There's a welding shop with a lot of drops, but they think highly of them. I think you're absolutely taking that for granted.

Same here. When I needed a 10 x 10 x 1/2 anysteel for a base plate for a toe jack the local guy said he would sell me a drop for $20. I passed on it.

[nickel-city-fab]

Spigot was a tight fit, too tight. I turned it .015 over, like I do with all of my faceplates. Guess that'll do it. I don't believe in centering off the spigot/register anyway.

LOL now I'm wondering if I've been doing it wrong all along. When I did the backplate for the 4-jaw, I gave it about 010 of clearance, and then "tapped" it with a lead hammer till the runout was 001, before I tightened the screws all the way. So far, so good. I thought all the flange style connections were *designed* to center off the spigot?

[J Tiers]

if the threads are halfway good, and the thing is finish turned in-place on the spindle (or a piece that simulates it accurately) I've never had a backplate that would not repeat well enough that I could not make the spigot for the chuck right on size and have it repeat well. I've made several.

Some of them had nasty looking threads, and even they work well.

[The Metal Butcher]

LOL now I'm wondering if I've been doing it wrong all along. When I did the backplate for the 4-jaw, I gave it about 010 of clearance, and then "tapped" it with a lead hammer till the runout was 001, before I tightened the screws all the way. So far, so good. I thought all the flange style connections were *designed* to center off the spigot?

There are hundreds of threads with differing opinions. I am firmly in one camp.

1. "Spigot" of the spindle to the backplate should be clearance.
2. "Spigot" of the backplate to the chuck should be tight. If tight can't be made or doesn't give desired runout, then undersized and bumped into place. Poor man's set true.

This method works well for me.

After I gave up, dad turned the spigot on the backplate undersized and bumped it in. It did not repeat.

if the threads are halfway good, and the thing is finish turned in-place on the spindle (or a piece that simulates it accurately) I've never had a backplate that would not repeat well enough that I could not make the spigot for the chuck right on size and have it repeat well. I've made several.

Some of them had nasty looking threads, and even they work well.

Agreed. I have too. Never had an issue. Until today. Based on the fact that the threads are threadmilled, I think they are oblong. So if you think of it in terms of the X and Y coordinates of a mill, the X or Y of the threads (one of the two) is longer than the other. So when the say X tightens up, the Y axis isn't tight, so it floats one way or the other. They countered this by making a tight spigot. Which is NOT (IMO) how threaded chucks are meant to work.

I will make one from bar. It will work good.

[lynnl]

Noah, I have a piece that's about 4 1/4" dia. and about 4 3/16" long. I don't know its DNA, but I think it's pretty good stuff; it hasn't rusted at all, still shiny but I'm pretty sure it's not stainless. There's a shallow divot in one end, maybe 1/8" deep ...1/2" dia. Looks like maybe a sibling piece was drilled through before being cut off.

You can have it if it'll work for you.

[The Metal Butcher]

Noah, I have a piece that's about 4 1/4" dia. and about 4 3/16" long. I don't know its DNA, but I think it's pretty good stuff; it hasn't rusted at all, still shiny but I'm pretty sure it's not stainless. There's a shallow divot in one end, maybe 1/8" deep ...1/2" dia. Looks like maybe a sibling piece was drilled through before being cut off.

You can have it if it'll work for you.

I think that would work. I only need just over 1".

[J Tiers]

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


Agreed. I have too. Never had an issue. Until today. Based on the fact that the threads are threadmilled, I think they are oblong. So if you think of it in terms of the X and Y coordinates of a mill, the X or Y of the threads (one of the two) is longer than the other. So when the say X tightens up, the Y axis isn't tight, so it floats one way or the other. They countered this by making a tight spigot. Which is NOT (IMO) how threaded chucks are meant to work.

I will make one from bar. It will work good.

OK, got what you meant.... Two different "spigots", got your intent mixed up.

Oblong would do it.... And all the "register" or "spigot" does then is cock the part off axis if the threads are AFU.

[JRouche]

I'm curious what you all would get and why

So I am making an ER40 collet chuck for dad for Christmas for his 10" Rockwell. I had a Shars set tru with backplate in my watchlist for ages, but it is OOS. So I ordred a 100mm version and now I need stock to make a backplate. I intend to buy a foot of 4" stock just to have some around for projects. It is nice to be able to afford that now.

So, looking on McM I can get

1. Cast iron $86, Tues
2. Ductile iron $99, Tues
3. 1045 $121, Tues
4. 4140, $200, Tues

On Midwest, I can get 4140 for $106, probably mid to late jan. Not going to be "Christmas" present.

So no matter what I get from McM I feel like I'm being ripped about 50% compared to Midwest, but midwest doesn't have the cheap irons. I love the way their cast iron turns, but it's lack of tensile strength is a let down. The ductile is probably a good choice. The 1045 doesn't really make sense since 4140 is objectively better. Probably matches the steel collet chuck best anyway. What would you do?

Yeah. I got busy, Late to the story,. You can have as much that you need. 2-1?2" 4140PH. I have two, many metal testers, 4140PH is at around 28..JR

[The Metal Butcher]

Yeah. I got busy, Late to the story,. You can have as much that you need. 2-1?2" 4140PH. I have two, many metal testers, 4140PH is at around 28..JR

I'm not sure I understand. Come again?

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I talked to Chris of LMS. He is intelligent and understood my issue. But ultimately offered no refund and I didn't push. As of right now I cannot recommend ANY little machine shop adapters. Low quality and poor design.

$50 down the drain.

[Captain K]

If it were me I would torch a blank out of large blind flange. I have a yard full of oilfield junk. Maybe you can find a plate drop somewhere nearby?