Need some custom lathe work done.

[ZuluWhiskeyFox]

Looking for someone that is willing to do a little custom lathe work for me. For a fee of course.

cheers,

zwf

 

[PEU]

sooner or later you will need to provide some details of what you need


Pablo

 

[unterhausen]

sooner or later you will need to provide some details of what you need


Pablo

i dunno price = nominal hourly rate * 1/(the amount of information provided) Is a pretty good rate

although the last person to post something like this in here decided to buy a lathe

 

[precisionworks]

Anything you want, normal shop rate is $1.25/minute but CPF members pay only $1.00 per minute. Plus materials & any specialty tools or tooling needed. Since I always start with a clean lathe (and mill) you also pay for cleanup.

the last person to post something like this in here decided to buy a lathe

+1

It doesn't take a lot of minutes to pay for a small 7X or 8X lathe.

 

[ZuluWhiskeyFox]

What I'm after is really quite easy.
A flat disk or slug of brass. .800" dia. X .25" thick
Threaded 20 TPI

 

[unterhausen]

I'm not sure how easy that is. If you want both sides of the slug to be flat and parallel, it either takes special workholding or a very good lathe. Never tell a machinist that a job will be easy, most of them will run.

 

[precisionworks]

really quite easy.
A flat disk or slug of brass. .800" dia. X .25" thick
Threaded 20 TPI

$25-$30 for one, price goes down as the number of parts goes up. Probably $3-$4 each in quantity of 50.

 

[gadget_lover]

I don't have any 1 inch rod, and would not want to cut down the 1.125 square bar to do it.

If I did I'd under cut Barry. I could do it for $29.95 each.

Seriously, The basic job is within the abilities of most home shop folks, but buying $20 of brass rod and the time to set up, clean up, mail, etc will drive the cost up.

Does it have to be brass? Any particular application? Different brass alloys have different heat transfer properties as well as different colors.


Daniel

 

[ZuluWhiskeyFox]

gadget lover had some valid points to consider. About the alloy of brass. I don't care about color. Heat transfer would be main concern. I'll need to solder to it as well. This is going to be the heat sink for a mod of an Arc LS. So it must screw into the head. If the mod works out the way I plan I'll be doing it 10 more times. As I have 10 empty shells need'n some innards.

cheers,

 

[will]

I would suggest that you send one of the bodies to whoever might do this. That would be to verify that the threading works with the body. I would also suggest that you get all of them made at that time.

Others can correct me - but I would just cut the diameter of the brass, then thread the entire length, then part off each slug. There are steps in between, like facing and putting a lead edge on the threads so they don't have to be deburred that would have to be done as well.

Brass is a nice material to work, most small lathes would have the power to do this work.

 

[unterhausen]

Others can correct me - but I would just cut the diameter of the brass, then thread the entire length, then part off each slug. There are steps in between, like facing and putting a lead edge on the threads so they don't have to be deburred that would have to be done as well.

the issue I see is getting that second face parallel to the first while clamping on the threads. If you could live with the parted-off surface on one side, then it becomes much easier. Then again, I'm not that good of a machinist.

 

[will]

the issue I see is getting that second face parallel to the first while clamping on the threads. If you could live with the parted-off surface on one side, then it becomes much easier. Then again, I'm not that good of a machinist.

You would have to create a jig to hold the part, it would have to be able to hold it, then expand to release the slug. A simple threaded holder most likely would not work because the slug would get jammed in it. This is why - there is no such thing as a simple job.

 

[metalbutcher]

I would think aluminum soft jaws would be a good way to hold the slug for facing the parted off side.:thinking:

Ed

 

[65535]

Once you part it a few second of sanding would net you a flat part. No need to face both sides.

 

[precisionworks]

.800" dia. X .25" thick

I'd probably run that part in a 5C collet, since the almost 100% peripheral support would not likely damage the threads. Without a 5C chuck, aluminum soft jaws would work just as well but have to be bored for that one diameter ... and couldn't be used at any other diameter.

thread the entire length, then part off each slug.

That's the way I see it also. Make a length of "all thread rod", using the follower rest for support while threading the long, slender part. Part off each piece to length. Some parting tools, when set up exactly right, leave a nice finish & no further ops would be needed.

Brass is a nice material to work

On that I disagree

Both brass & cast iron are "short chipping" metals. That means there are no spirals of metal, just a continuous spray of hot, nasty stuff. Both brass & CI get into every crack & crevice, gum up the chuck, and are generally a pain to work. Brain surgery is easier

 

[ZuluWhiskeyFox]

In this application I think one side of the slug need not be faced. The one faced side will have the emitter board glued to it. While the unfaced side will have an electrically isolated positive battery contact glued to it ala arc LS.

 

[will]

On that I disagree

Both brass & cast iron are "short chipping" metals. That means there are no spirals of metal, just a continuous spray of hot, nasty stuff. Both brass & CI get into every crack & crevice, gum up the chuck, and are generally a pain to work. Brain surgery is easier

I should have said - Brass is a nice looking material when it is finished. I agree with the short chips, the other issue with brass is drilling. It tends to suck the drill bit in. For long drilling jobs with brass, we used grind a flat on the edge of the drill.

 

[darkzero]

What I'm after is really quite easy.
A flat disk or slug of brass. .800" dia. X .25" thick
Threaded 20 TPI

This is going to be the heat sink for a mod of an Arc LS. So it must screw into the head.

I would suggest that you send one of the bodies to whoever might do this. That would be to verify that the threading works with the body.

I remember when I used to say silly things like that. Sounds easy but lots of times it's not that simple, quick, or cheap.

The thread on the Arc LS is 13/16-20. I've modded lots of Arcs over the years & I've found their threads to be very loose. 13/16" is .8125", if you get heatsinks made with a dia of .800" they will be very loose. Even .8125" with the proper pitch diameter can be loose, well too loose for my preference. But a loose fit can help with centering the emitter if it's off.

I agree with will, it would be best to send a body to the machinist to have the heatsinks fitted. Once one is made & you like the fit, you should have that machinist record the dimensions if you plan to have more made from them.

When I make heatsinks for the Arc LS, I fit the thread to the body I'm working on. Most of the time the pitch diameter is larger than what a 13/16-20 calls for but my concern is not compatibility as it's intended only to be used in that body.

If you can find some, I used to use e-screws as a heatsink for the Arc LS that I modified, if you remember the old Aleph Luxeon LEs. Here's a few of examples:

http://www.candlepowerforums.com/vb/showthread.php?196106-**Arc-LS-SSC-P7-TriFlupic-Mod**-UPDATED
http://www.candlepowerforums.com/vb/showthread.php?204825-Gold-Arc-LS-Cree-XR-E-Flupic-Mod
http://www.candlepowerforums.com/vb/showthread.php?202473-Arc-LS-SSC-P4-Flupic-Mod



I'm working on another Arc LS mod right now. If your interested, I can send you the left over piece from the heatsink I made that was thrown into my scrap bin. As I mentioned, the pitch diameter is larger than spec & I fitted this heatsink to the body I'm working on. It may or may not fit your bodies (I just checked it it fits some bodies I have & some that it won't. It measures just over .31 thick & you can file it down to size. Both sides are faced. Cover the shipping cost & it's yours. I can't offer to do any other work on it though & I'm not responsible if it doesn't work out for you.

On the right:

Brass is a nice material to work, most small lathes would have the power to do this work.

Agreed, I love machining brass (just don't like cleaning it up). Here's the same size 13/16-20 thread that I did on my 8x14.

 

[precisionworks]

Awesome threading

I'm guessing that a run of 10 pieces could be done for $75 in labor. For a one foot piece of 7/8" diameter Brass 360, McMaster charges $25.35 + tax + shipping, roughly $40 total for material. So $115 for ten pieces.

 

[unterhausen]

Some parting tools, when set up exactly right, leave a nice finish & no further ops would be needed.

I need a better parting tool. I knew this already