One valve done...one more to go

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deere_x475guy

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Ok, after a little failure I finally had some success.





I machined this w/o a steady rest and used a freshly stoned lathe bit. I tried using stainless on the first one and had a terrible time. So the second time around I used drill rod.


This shot just wouldn't come out clear like I wanted but if you look closely near the face of the valve you will see a shiny ring. That is where I lapped the valve to the valve seat before I parted it off. I mixed some valve grinding compound with my cutting oil then ran the lathe at 60 rpm until I could see a continuos shiny spot around the valve. I hope it's going to seal well enough.







 

deere_x475guy

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Well it took me 6 hours to successfully complete the first one. Only an hour to do this one....guess I learned something along the way.:))



I think I am going to use these w/o hardening them and see what happens.
 

Mcgyver

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you got her done, that's the important thing....what grade of stainless were you using? if you use 303 or a free machining grade it'll be easier than drill rod, if you were using say 304, yuck

the other thing to try when working on long slender pieces is to take it all off in one cut....ie if you need 1/16 dia an inch long, that can be tough to machine but not if you start with .375 material with a .156 depth cut (and very slow hand feed)
 

chuck foster

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another way is to make a two piece valve, head and stem separate. the head is a nice tight fit onto the valve stem that is made out of drill rod. turn down the valve stem (made out of drill rod that is valve stem size) the part turned down is longer that the head is thick. drill a hole in another piece that is the valve head diameter,part the head off and slip it on to the valve stem. with the head pushed right up to the shoulder on the stem take a small hammer and rivet the head on. cut the valve angle on the head and you are done.
i have done this for most of my models and it works very well and it is fast.
the valves for my little angel are one piece cause i couldn't find 0.032" dia drill rod for the stems!

regardless of what way you did it.................you did it and thats the important part!

chuck
 

rake60

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Looks Great Bob!

6 hours on piece #1 and 1 hour on piece #2 is right in the "normal" range.

Now tell me honestly, which of the two was more fun to make?

Once it's all figured out it becomes a production job.
There are lots of "machinists" out there earning $8/hr doing just that.
I can guarantee you, none of them would ever be able to make that first
valve as you have.

Great work!

Rick
 

deere_x475guy

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Chuck and Rick thanks for the compliments. ;D

Chuck the plans did talk about making it with two pieces and maybe someday I will try that method also. Never hurts to learn different ways of doing the same thing.

Rick both were fun to make! Actually it was 3. I destroyed the first one trying to be fancy while cutting a grove for a c-clip to hold the spring on instead of drilling a hole for a cross pin. I know now that if I wanted to do it that way I should have turned down to diameter just enough of the end to cut the grove then finish turning down the rest. Instead I turned down the entire length then went back out to the far end to make the grove. I figured it was just a little grove (.015) and I should be ok.....haha...live and learn. ;D In a way I knew better I just couldn't help myself ;D. All in all I call it a very good day in the shop. Heck everyday is a good day in the shop!

Thanks again guys!
 

cfellows

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deere_x475guy said:
I destroyed the first one trying to be fancy while cutting a grove for a c-clip to hold the spring on instead of drilling a hole for a cross pin. I know now that if I wanted to do it that way I should have turned down to diameter just enough of the end to cut the grove then finish turning down the rest. Instead I turned down the entire length then went back out to the far end to make the grove. I figured it was just a little grove (.015) and I should be ok.....haha...live and learn. ;D
Another fairly painless way to cut grooves in small valve stems for e-clips is to use a dremel tool with a small abrasive cutoff blade. You have to make a fixture that lets you attach your dremel motor to the cross slide on your lathe. This probably produces a groove with a rounded bottom, but it works great. By the way, I wouldn't try to use the dremel freehand to cut the groove. You probably wouldn't get very good results.

Chuck
 

deere_x475guy

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Thanks Chuck, more projects..! I have a couple of chucks of mild steel set aside to make another tool holder and a holder for the dremel tool I have. Another thing I was thinking about making is a tiny follower that is part of the tool post. I remember seeing a post where one was built for turning the tiny parts.
 

BobWarfield

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Nice work, Bob!

If you're in a mood to contemplate gadgets, have a gander at an article I wrote on my blog:

http://www.cnccookbook.com/CCBlogSep2007.htm

Go to that page and search down for "http://www.cnccookbook.com/CCBlogSep2007.htm"

There's some interesting stuff on some fairly unique follow rests for doing small skinny stuff like your valve.

Those little goodies don't look too hard to make, and sure could be a life safer for such exacting work.

Cheers,

BW
 

deere_x475guy

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Bob thanks for the compliment and the link. That's the one I remember seeing. I just printed Frank's page off for future reference.

Spent the morning cleaning the shop and doing a pm on the lathe and just sitting and relaxing in the shop right now. The place was so cluttered and out of sorts I couldn't focus on anything. ??? ???.
 

BobWarfield

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When I know I should be in the shop, but I'm wasting time on the computer, I find going down and straightening up a bit will put me right in the mood to get cranking on another project.

I'm in the middle of reorganizing my shop. It's going slowly but surely.

Best,

BW
 
S

Swede

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Very nice job! Making small stainless steel valves can be a real pain in the tuckus, and making them seal well, that's more pain! ;D

Some thoughts on 2-piece valves - I like doing this, and it is a real time saver if the valve stem is some common dimension like 1/8". I like silver braze for the job, and given that silver braze needs a bit of a gap to fill, what I do is ream the valve head portion to 0.126" or maybe 0.127" for a 1/8" stem, then give it a slight counterbore, for perhaps 0.032" deep by an additional 0.005". On the stem, at the point where the valve stem matches the counterbore, turn a very light "V" form with a threading tool, so you are creating an undercut.

What this means is that when you hand assemble the stem to the valve head, because much of the fit is close sliding, the valve assembles accurately, yet there is both a very slight gap in the bulk of the assembly, and a significant and primary fill area at the counterbore and stem junction. Create ringlets of braze, apply gobs of good flux, and a regular propane torch will do the job very quickly on a small valve. If you use a thin, hi-flow braze, you should see a circle of braze on the bottom of the valve, where it flowed all the way through. This type of assembly will be plenty strong except perhaps if installed in a very hot, high-speed "racing" type of engine.

One last thought - to seal well and not stick, give the valve stem to guide interface probably more clearance than you'd initially think. it is very tempting to ream the guide so you get a near "hydraulic" type of fit, but this will stick badly when running and not seal nearly as well as it would with a looser fit. I'd say 0.002" for a 1/8" valve. It'll feel sloppy, and we don't normally like slop, but it is necessary. This aslo allows a bit of oil to migrate and lubricate both the stem, and the rocker area.

Anyway, again, great job on the valves! Now think about making 18, or 36, plus spares, for a radial engine! :D
 

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