# I need E-head threads cut on a 6P body



## Blindasabat (Mar 13, 2009)

I have one of Fivemega's 18500 SureFire E-series clicky bodies - love it - and it is the only E-series body that I know of that fits an 18mm diameter battery. It is very thin under the bezel threads, but works.

I would like to make a custom 18500 body that has E-head to C-tailcap threads so i can use one of my McC2S tailcaps on an 18500 E-series light. It should be easy to cut the bezel threads on a 6P body (or equivalent). I have a donor Solarforce L2 body to machine. I have measured it up and there is material for the new bezel threads in the Solarforce body if you shorten it to 18500. 17500 might be OK if that is all you feel comfortable machining, but I prefer 18500.

Is anyone interested in making one of these for me? PM me an offer. I'm poor, so I hope I can do this for a reasonable price.

I'm sure you could sell more of these if you chose to.


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## Blindasabat (Mar 17, 2009)

It's simple for someone with a lathe that can do threads. 

1) Cut the bezel end off to a length of 66.5mm tube remaining.
2) Take the first 6.5mm of the new cut end down to 20.64mm (13/16") Diameter. 
3) Cut an o-ring groove at the base of where the new bezel threads will be. Dims TBD, but ~1.5mm wide by ~0.5 deep.
4) Thread new head area 20TPI.
5) Bore to 18.6mm

I'd prefer the tail then cut down a mm since I have a big gap from the TC to the body with my intended TC.

I have a sketch, but since I don't have CAD software access anymore, it is just a sloppy hand sketch of the x-section with the new bezel threads sketched in with the dimensions above. But it's so easy!


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## precisionworks (Mar 17, 2009)

You'll probably have better luck in the Homemade & Modified Lights section.


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## Anglepoise (Mar 17, 2009)

precisionworks said:


> You'll probably have better luck in the Homemade & Modified Lights section.






65535 said:


> This is not the place to ask about work to be done. This is for the machinists. Look at Home-Made-Modified.





This is the second post today to MMM where the OP has been re directed
to other areas of CPF.

Are not we the guys who do this sort of thing?


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## precisionworks (Mar 17, 2009)

I imagine that many of the modders read this section, and quite a few post here frequently. So why has no one offered to do these jobs?



> But it's so easy!


Whenever a customer says this, I know that the other local shops have quoted high ... meaning some significant amount of time involved. Starting with a clean lathe, doing the different ops including tooling changes, and cleaning the lathe again is easily an hour of billable time. That's anywhere from $60 to $90, depending on your geographic area.

It's certainly doable, but I wouldn't call it easy


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## gadget_lover (Mar 18, 2009)

I did not offer because;

1) I don't have enough free time for my own projects

2) While it's "easy", the piece will be ruined if any of several mistakes are made.

3) I'm never satisfied with my work anyway. 


There's a good chance that someone will offer to do the job if you are willing to pay normal fees.

Barry left off the time required to package and mail a small part.

Daniel


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## precisionworks (Mar 18, 2009)

> the piece will be ruined if any of several mistakes are made.


+1

Fatal mistakes are ONLY made during the last op ... like going .005 over, when the max tolerance is +.0005


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## wquiles (Mar 18, 2009)

Anglepoise said:


> This is the second post today to MMM where the OP has been re directed
> to other areas of CPF.
> 
> Are not we the guys who do this sort of thing?



I think it is OK to ask questions here, but in the end most folks who ask for these type of mods in this subforum, don't have a good appreciation of the time, money, and risks that go along such custom work. They quickly disappear once you give them a quote and they realize it is not as "simple and cheap" as they tough was going to be.

Will


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## Anglepoise (Mar 18, 2009)

wquiles said:


> I think it is OK to ask questions here, but in the end most folks who ask for these type of mods in this subforum, don't have a good appreciation of the time, money, and risks that go along such custom work. They quickly disappear once you give them a quote and they realize it is not as "simple and cheap" as they tough was going to be.
> 
> Will



I agree 100% with your post above.

What I don't agree with is turning away people that want help. They are told to post over here. We send them back.
I am not suggestion we have any obligation to accept the odd job, or even reply to a post. However this is
the machining area, and I don't think we should turn them away.


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## Blindasabat (Mar 18, 2009)

*Re: I need E-head threads cut on a 6P / Solarforce body*

Thanks for the feedback guys.

I posted here because this is where actual machinists check in from time to time.

I think you can see I'm not a newbie - I've been around a while. I don't expect it to be a $30 job. I am an engineer, taken a class in machining (outside of university) and worked with machinists many times before.

When I said it's easy, it was to assuade those that mioght not know where to start design-wise. I already figured that part out. The material is there and I have the dimensions to cut to. 

I was going to post this on MFGquote, but because my computer is getting old and won't fit CAD software anymore, I didn't feel comfortable posting a hand sketch there. Plus two other things: guys here are more likely to know how to do this & aware of the details that might trip up a non CPF fabricator, and I got a $14 Solarforce L2 body to modify, which I honestly think would spook non CPF guys too. They would more likely want to start with fresh stock exactly because they don't want to mess up what they would see as an item that will be difficult or expensive to replace no matter what I tell them it cost. Non familiarity would add cost. Modders here do machining on existing parts a lot more often. I understand the likelyhood of making a mistake is there, and that is why I bought a cheap Solarforce body to work on. If it gets messed up, then I buy another one and start over. At my expense.

I didn't specify a price, only saying I was looking for something reasonable because I don't know what it will cost, but I'm not looking for an extremely pretty part, just something that works. And I'm not rich. I am just looking for estimates. If anyone messes up my donor, I will get a new one at my cost. I'd prefer it to be anodized, but if it really would be easier to machine a whole one from scratch, then let me know. I do think it would be easier to start with what I have.


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## PhotonFanatic (Mar 18, 2009)

Blindasabat,

I must admit that when I read your OP, that I wasn't the least bit interested in helping out. The fact that you emphasize that you are poor, yet then ask for a reasonable price, led me to believe that you wanted the work done cheaply.

Unfortunately, cheap prices in the machining world often means cheap workmanship.

Also, while you are familiar with your light, you never provided any dimensions that might have allowed me to decide if I could handle the job. What is the maximum diameter that needs to be chucked? How long, or deep, is the bore? Things like that, upfront, can help someone like me decide if I can do the job or not.

I recently did a cut-down and threading of a two cell body to a one-cell length, cut the O-ring grooves, etc. My charge for that work was $80--but the customer has also ordered a custom Ti light from me, so I went out of my normal routine to do that job for him.

Most likely I, or a lot of others that frequent this sub-forum, can do the job for you, but a straightforward approach without the whining would have been better. 

Provide more info on the max diameter and I will at least let you know if I can do it, or not.


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## Illum (Mar 18, 2009)

Blindasabat said:


> I have a sketch, but since I don't have CAD software access anymore, it is just a sloppy hand sketch of the x-section with the new bezel threads sketched in with the dimensions above. But it's so easy!




Sketching and machining are too separate magnitudes of difficulty

I've had more the one student in drafting class who told me to work as a machinist before I go and design something, as some objects are both ridiculously easy to draw and ridiculously hard to create....I hope in the future 3D printers might help with the issue


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## precisionworks (Mar 18, 2009)

> work as a machinist before I go and design something


Remember, it takes an engineer to design something impossible to machine:nana:


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## wquiles (Mar 19, 2009)

Anglepoise said:


> I agree 100% with your post above.
> 
> What I don't agree with is turning away people that want help. They are told to post over here. We send them back.
> I am not suggestion we have any obligation to accept the odd job, or even reply to a post. However this is
> the machining area, and I don't think we should turn them away.



Well said. We should not "send them away".

Will


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## Illum (Mar 19, 2009)

precisionworks said:


> Remember, it takes an engineer to design something impossible to machine:nana:



oh, you'd be impressed by what a no0b Pro-Engineer user can do with stuff like..._paste special_ to create abstract designs that looks cool...but you can't even dimension it


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## 1wrx7 (Mar 19, 2009)

Illum said:


> Sketching and machining are too separate magnitudes of difficulty
> 
> I've had more the one student in drafting class who told me to work as a machinist before I go and design something, as some objects are both ridiculously easy to draw and ridiculously hard to create....I hope in the future 3D printers might help with the issue


 

The joke at my work with the engineers is... they say, "well, it works on paper". My reply... "next time I build a machine out of paper I'm sure it will work fine" It's like the age old battle between cats and dogs.

Blindasabat, another option may be finding a local machine shop. I don't have to tell you about the economy in MI right now. A lot of machinists are trying to look busy at work. The cost might only be a case of beer:naughty: I would offer to help out but, the machinist who handled my pet projects got laid off:sigh: They actually shut down our whole CNC dept. I do have one of the E head-C tail 1X123 ribbed body's that Dafabricata and I made left. If you're interested PM me. I also need to send you some $$ for the get-together


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## Blindasabat (Mar 20, 2009)

Geeze guys, this is ridiculous. 

It's been almost 20 years since I was a new engineer grad trying to get things made by balking machinists. This takes me way back... Then as now I was more experienced than they assumed. I had designed and built three complete competition cars from the ground up (frame and all) before graduating college. One got 490 MPG in international Society of Mechanical Engineers Supermileage Car competition, placed only 9th with a budget 15% of the other top 20 teams, earned my university a prize, and the winning car copied my steering system the next year. The next one I built for the Formula SAE race car competition, used a motorcycle engine, got far worse mileage, but still beat many big schools with big budgets in our first year. One of our sponsors was the National Center for Tooling and Precision Components. I ran the teams, designed the cars, made machining and assembly drawings on AutoCAD (I was an instructor while still a student) and assembled everything. The shop loved my CAD drawings. Especially compared to the grad students' napkin sketches.

After college the engineers and I used to joke that we had to put MIL TDP41 'spec' on our prints when we give them to the shop ...we have our appropriate jokes too. (Make it like the d**n print 4 once)

The donor is a Solarforce L2 with a 31.5mm head I will now cut off. The body remaining body is 25.1mm measured by my calipers.
I found a die for the threads and if my buddy gets his Bridgeport restored soon (probably not) I will just do it on that.

Thanks for the input.


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## gadget_lover (Mar 20, 2009)

Blindasabat said:


> Geeze guys, this is ridiculous.
> 
> It's been almost 20 years since I was a new engineer grad trying to get things made by balking machinists. This takes me way back... Then as now I was more experienced than they assumed. I had designed and built three complete competition cars from the ground up (frame and all) before graduating college.
> 
> ...



First, I'm glad that you will be able to get what you wanted. That's good news.

Second, given that you are a seasoned engineer I'm VERY surprised that you wrote the original post. In that post you mention 4 different flashlight parts, and never said which one you wanted modified. The only dimensions mentioned are indirect, as in "shorten it to 18500". No threads, no diameters, no tolerances, no pitches. Since 18500 is (presumably) a battery, it's not a good unit of measure.

In that post you also said that you were doing the mods ("I would like to make a custom 18500") but then went on to ask if others would want to do it for you.


All in all, it was confusing. I guess it's time for a sticky about how to ask for help or for custom work. We usually have to tell newbies what a tolerance is anyway, and how to measure things, so we can cut and paste from previous posts.

Again, congrats on finding a solution.

Daniel


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## StrikerDown (Mar 20, 2009)

I am chuckling at this thread. Some of the regulars here know that I am still wet with coolant behind the ears as far as being a "machinist" wannabe, so I can't really comment about the technical aspects of the proposed project.

But, I am somewhat of an expert in my field, that being printing, pre-press and graphic reproduction. The reason for the chuckling is that we have the same love hate relationship in this industry between designers and production and so it went in a former life as an electronic technician... You know it takes a minimum of two technicians to keep one engineer out of trouble! 

In printing and graphics since the proliferation of the PC to every home as far as the eye can see everyone has become a graphic designer and the computer hardware has the power for everyone to design their project just as ugly as their hearts desire!

I can’t tell you how many times I have heard “ but it prints fine on my desktop printer why can’t you print it... you must not know what you are doing!” Well let me put my printing press on your desktop and all will be well! OOPS! that was my inside voice! lovecpf


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## Blindasabat (Mar 21, 2009)

I think the line "Is anyone interested in making one of these for me?" was clear. I'm trying to make a flashlight, for which I need machining done. I admit the OP was not worded perfectly clearly (I perhaps over edited it from a longer initial draft in an attempt to keep it short), but anyone could ask for clarification if interested and I would have gladly explained further and given some dimensions. The point was to see if anyone was interested in doing some battery tube machining, not fully descibing the exact job in detail without a drawing, which I would not try to do. I think most people understand that any initial question may not be clear, additional info may be needed. I've seen it go that way many times here on CPF without the sniping. People do not all think the same way and arguing the exact wording of a post is silly as opposed to asking what the poster meant.

Nobody has quoted this yet, local or otherwise. Before posting I asked several members via PM who do or have done similar parts and they were too busy (which I fully understand), or didn't do one-offs, which I also understand and respect. The shops I have worked with locally are not generally interested in such small work while people here on CPF have done very similar things before. Some already have programs written to machine almost this exact thing, so I assumed this is the place to go to get a battery tube cut. 

I have not decided to do it myself yet, but it appears I will have to and have started to prepare for that. I was willing to pay a fair amount, but my effort to save the time of anyone planning to quote $200 for what I'm sure would be a work of art, perhaps worked too well. If I scared anyone off, I apologize. Now I'm off too.


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## PEU (Mar 21, 2009)

Blindasabat said:


> I would like to make a custom 18500 body that has E-head to C-tailcap threads so i can use one of my McC2S tailcaps on an 18500 E-series light. *It should be easy* to cut the bezel threads on a 6P body (or equivalent). I have a donor Solarforce L2 body to machine. I have measured it up and there is material for the new bezel threads in the Solarforce body if you shorten it to 18500. 17500 might be OK if that is all you feel comfortable machining, but I prefer 18500.
> 
> Is anyone interested in making one of these for me? PM me an offer. *I'm poor*, so I hope I can do this for a reasonable price.
> 
> *I'm sure you could sell more* of these if you chose to.



IMHO, most of the replies (or lack of them) were rubbed the wrong way by the highlighted parts of your post. 
Bad choice of words, probably, bad intentions? Im sure not!... BUT we all heard that before: yeah its easy, with your machines its 1-2-3 and presto! its done! only to figure out later than its a nightmare or not as easy as it was explained. Then you said you were poor, nothing bad with being poor, but it sounded like you were willing to pay less than usual, usual being whatever the machinist wanted to charge you (hourly/per job/whatever rate) for the task and to put the cherry on top, you offered a business plan to make more as an extra bargaining method... 

Anyway, I hope you aren't offended by my reply, I just tried to let you know my point of view.


Pablo


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## TranquillityBase (Mar 21, 2009)

> I would like to make a custom 18500 body that has E-head to C-tailcap threads so i can use one of my McC2S tailcaps on an 18500 E-series light. It should be easy to cut the bezel threads on a 6P body (or equivalent). *I have a donor Solarforce L2 body to machine*. I have measured it up and there is material for the new bezel threads in the Solarforce body if you shorten it to 18500. 17500 might be OK if that is all you feel comfortable machining, but I prefer 18500.


 

What is the I.D. of Solarforce L2 body?

EDIT: If the Solarforce body is .677" ~ .680" I.D. you're correct there is enough material for E-series threads on bezel end. The cell body would have to bored from the switch end to accept the 18mm cell (but not bored all the way through, because of the o-ring groove on the bezel side .750" O.D.), the *rub* may be the o-ring groove at the switch end. If that o-ring groove O.D. is the same as a SF C-series body, boring to cell tube to fit the 18mm cell will make this area the weak point.


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## will (Mar 21, 2009)

TranquillityBase said:


> What is the I.D. of Solarforce L2 body?
> 
> EDIT: If the Solarforce body is .677" ~ .680" I.D. you're correct there is enough material for E-series threads on bezel end. The cell body would have to bored from the switch end to accept the 18mm cell (but not bored all the way through, because of the o-ring groove on the bezel side .750" O.D.), the *rub* may be the o-ring groove at the switch end. If that o-ring groove O.D. is the same as a SF C-series body, boring to cell tube to fit the 18mm cell will make this area the weak point.



Be careful with the Solarforce body, It is 2 pieces that are screwed together. There is also some 'glue' holding the 2 parts together. I had to boil these in water to separate the parts. I don't know what the threads are, but the threads that hold the 2 parts together and the thread where the tailpiece screws on are not the same...close, but not the same.


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## Blindasabat (Mar 22, 2009)

The ID of the body is 17.4mm (0.685"). 

I had noticed a groove on the inside of the tube and wondered what it was for, why it was there, and how they machined it. Mystery solved and a new problem. Those threads overlap where the E-threads would have to be on an 18500 tube by about 1mm. That might still work. Hmm. The contact might be short though. I will have to break mine apart to measure it up better.

Thanks for the info, even if it is bad news.


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## TranquillityBase (Mar 22, 2009)

That split in the body may be a great place for an adapter:shrug: Have you measured the o-ring groove (switch end)?


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## Blindasabat (Mar 22, 2009)

TranquillityBase said:


> That split in the body may be a great place for an adapter:shrug:


Good idea... I haven't fully laid it out yet, but according to some quick caliper measurements, to make an adapter work for an 18500 cell (the one I want it fit to), I'd have to cut the tailcap end of the body down and re-thread it inside to make it shorter. The current split-body threads only overlap the intended E-threads by ~1mm. I bet I could stack up two single cell CR123 extenders and cut one down as the adapter... 
More research required. I will have to take apart the Solarforce L2 to measure it up.

To make an 18650 body an adapter would work well on this tube. Solarforce makes an 18650 body, so that is a definite possibility for anybody to persue.



TranquillityBase said:


> Have you measured the o-ring groove (switch end)?


The o-ring grooves are 19.4mm on the 6P and 19.8mm on the L2, so neither should be a problem boring to 18.3mm. My 18650s and 18500 cells measure 18.25mm max OD at the wrapper overlap so I'd be OK with 18.3mm bore.


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## will (Mar 22, 2009)

I have been boring the L2 bodies to fit an 18XXX battery, I generally open it to .740 inch. I have had success making a bushing and press fitting pieces together. You have to be able to machine to very close tolerances. 

Solarforce has a converter 6P - to 9P, basically a short tube, They also have a 3P sized body.


The original Surefire 6P body looks to be one solid piece.


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