Making Star dies--My Methods

[Morgan Astorbilt]

Lathesmith, Nice job mounting the grinder on the tool post. Before I got my Dumore, I used my Craftsman 1/4" die grinder mounted in a tool post holder Sears sold for them.
Morgan

[lathesmith]

colby, thanks for running the heat-treat tests, that ought to be interesting.Case-hardening those mild steel dies did occur to me as a possibility, but I wasn't sure how that would affect surface finish and dimensions. Keep us posted....

Morgan, I also had your idea of getting one of those Dumore TPG's on ebay, I have seen those go for really reasonable prices. I wasn't sure how they would adapt to my small lathe though, so I finally went the Proxxon route. I may yet get one of those Dumore's, they also offer outside as well as inside grinding ability, which could come in handy for a wide range of things...

I'd be curious to know what you use for inside grinding and finishing of your sizer dies with your TPG. The best I have found is a Dremel brand, long slender stone, meant for chainsaw sharpening. This is a 1/8" shaft. I have tried others, but they are either not quite long enough, or the concentricity is poor, or the quality is just not quite good enough.

lathesmith

[Morgan Astorbilt]

lathesmith, I buy all my stones, both mounted and unmounted, from MSC. The majority of them are Norton, but I've have had good luck in the past, with their USA made no-name stones, including assortments that are sometimes on sale very inexpensively. Some of the cheaper ones have to be fed with less pressure than the Norton's. You can also get a mandrel(Craytex, not Dremel) for small wheels, a bit larger than your grinder nose, and do some outside grinding.
Morgan

[colbyjack]

i case hardened the mild steel one, probably .010" depth and i tempered it. it sits at a RC 50/52. i will have cycles this coming week to run the tool steel ones. i looked up the W1 its a water quench metal. 1450 for a hour carbon setting at a .70 probe and water quench no agitation. very time sensative must temper ASAP. ill see how that works. the o1 will be oil quenched. my hardness should be harder than the backyard heat treat cause of the elavated carbon settings. ill keep ya posted to how they turn out. then you can take a look and see what you think. -chris

[lathesmith]

That sounds good colby, .010 would be plenty. How did this affect diminsions? How about finish? I would think RC 50+ would be plenty hard, probably harder than I can get with my backyard method. Good work!
lathesmith

[colbyjack]

ill let you do the measurements and such. when i get done ill mail them back to you. -chris

[Buckshot]

............W-1 will harden to the point that it will make file teeth shiny It also has a tendancy to shrink a bit, and thin sections can warp when quenching, or even crack.

..............Buckshot

[lathesmith]

I had assumed that the primary difference between W-1 and O-1 was that O-1would have less dimensional change after tempering than W-1, and that it also has better tempering qualities without the risk of damage that Buckshot describes. I can't tell any difference between the two when machining, both seem to machine equally well with either HSS or my TCMT carbide tools. Also, both of these steels get much hotter while machining than does cold- or hot- rolled steel. I know some of you large lathe guys will laugh, but I use oil and water as coolants while machining and drilling. I mainly use motor oil while drilling, and I apply water with a chip brush while machining the OD down to size. No, this ain't fancy, and it's not as efficient as either a mist or flood coolant setup, but it also isn't too messy , and it keeps the workpiece and tool MUCH cooler. I trashed a couple of TCMT inserts until I figured out they were running too hot; I haven't even dulled one since I started my water treatment. It works for me....
lathesmith

[Morgan Astorbilt]

Why not try some coolant, such as soluble oil mixed with water, for both? The oil will lubricate, and the water will cool the tool, allowing faster speeds. The only time I use straight oil, is for threading, kero for aluminum. When not using the coolant pump on my lathe, I use an acid brush in one of those plastic tip-proof bottles, or a windex-type spray bottle.
Morgan

[lathesmith]

Morgan, those are all good ideas. I'll probably order some of that water-soluable stuff from Enco, the next time I need to order from them. I was just using what I had available, and discovered that it really did help keep things running cooler and smoother. Even with those 3151 TCMT's, when I keep the metal cool and my speed higher I can get a decently smooth finish on that O-1. I probably won't go with a full flood coolant setup with my small lathe, but just using some from a brush or spray bottle would be a big improvement, without as much mess as the full flood treatment.
lathesmith

[Willbird]

The water hardening tool steel is more prone to cracking in heat treat, HOWEVER it is probably very well suited to a bullet sizer die.

I remember reading in a book about steels that you can PRESSURE quench a bushing or other part that does it's "work" on the inside of the hole. The rig to do it involved a water pipe, and a certain amount of "head pressure", IE the water would go up 6" or 12" from the pipe when the valve was opened...they had a jig that allowed you to QUICKLY set the part in then turn the water on....this makes the inner bore hard as the hinges of hell, and the metal gets progressively softer the deeper you go...which adds strength....this is an almost ideal situation for a drawing die......maybe overkill for a star bullet sizer die .

The key thing with a water hard steel is to avoid stress risers, and make the part symmetrical.....a star bullet sizer die might work out just fine....the lube holes MAY provide a location for it to crack ?? maybe not.

There are often a lot of "drops" of tool steels on Ebay.

Bill

[colbyjack]

the w-1 is a pain in the butt it will crack easy, it will crack if its too hot when it hits the water. you need still water no agitation and you need to get it in the temper ASAP. -chris

[Shotgun Luckey]

You still making the dies to support the site??

[lathesmith]

Yes, I am still making these dies, but I will be taking payment directly for awhile to help offset some of my equipment and tooling costs. Together with the guys on the forum, we have made a nice chunk of donations for the boards here. I wish to continue making these dies, and periodically making donations to the site in the future. Thanks for all the help and support!
lathesmith

[Cayoot]

You guys (who have the skills to be machinists) amaze me!

The skill seems more like magic then a trade. It looks facinating, but wayyyy beyond my grasp!

[colbyjack]

you shoulda got them back in the mail by now. howd they do chris? -chris

[lathesmith]

Hi Chris,
Sorry about that, I meant to send you a message earlier. Yes I did get them back, and they look beautiful. I will keep these as reference, and this info will give me a benchmark to refer to in the future.
I was also wondering, if you have a way of testing hardness, would it be too much trouble if I hardened a die using my torch method, and then sent it to you for a hardness check? I know, doing it the way I do they are going to vary some, but I think it would still be an interesting check. What do you think about this?
lathesmith

[colbyjack]

sure sendem, try to keep the heat even over the whole part and get it hot all the way thru. if your water quenching, room temp water is better than cold. toss it in there soon as you get off the torch. do not agiatate the water. still water quench is fine. 3/4 mins in the water is plenty. you def want to give these a temper. get a small lil counter top oven, at least a 350 temper, tool steel should get a double draw, but you can cheat it with a 3 hour temper. but these are small enough 1 hour should be fine. if you can get it hotter in the temper go for it. id say 500 or so. its not going to change the hardness.

let me know how much you want for a .452" die? i may be interested.

on one of them i cleaned it up with the fine bead blaster, it came out real dark in color. they are way over file hard so it didnt hurt it.

let me know if ya need anything else -chris

[cbrick]

lathesmith,

Haven't seen anything on this thread in a year, are you still making the dies?

Rick

[lathesmith]

Hi Rick,
Yes, I'm still making Star dies, and also punches, locknuts, and locknuts with setscrews. All kinds of great and interesting stuff for Stars!
lathesmith