Surefire boring service

[precisionworks]

Barry,

Thank you for the compliment

You can tell that I'm obsessive about the way machine work is done, something beaten into me by one particular boss whose standards were very high. He rarely ever asked me to rush a job, but he demanded a scrap rate close to 0.00%. That experience was valuable, as I now run a mill in a small tool & die shop that makes assembly jigs & fixtures. Every part that leaves the shop is carefully machined, 100% inspected, deburred, chamfered, ground smooth, and black oxide treated ... gorgeous parts that no customer will ever see.

Lights certainly fall into the class of high end industrial tools. They need to look just as good after boring as they did when they arrived. Quite a few modders run a boring bar through the tube & call it good ... it is functional, but it leaves a finish that can be improved & refined. High end lights deserve the additional steps of reaming & honing to produce a perfectly straight & round bore, with a finish that looks as good as it possibly can.

Boring a relatively long, small diameter tube always presents a challenge. The boring bar is often extended to the maximum, which means that the bar may cut a surface that tapers slightly - running the bar into & out of the tube (without changing the depth of cut setting) will help offset this. Following up boring with reaming produces a near perfect cylinder that is dead on for size, straightness, and surface finish. Honing then refines the reamed surface by removing any microscopic high points, and by blending in the low areas. Brush Research Manufacturing, who makes the Flex Hones that I use, describes this on their site: http://www.brushresearch.com/flex-hone-tool.php

Didn't mean to rant

[genius5th]

got my two light bodies and they rock! Barry is a perfectionist. The lights looked stock, which is hard to pull off, I was thinking I could see some modifications on the inside but it looked like it came from the surefire factory. I'm also glad the outer body was protected
and came back without any scratches. Thanks sir!

[beach honda]

Yessir!

Barry did an outstanding job with my C2.

Thanks bubba!

-Chris

[precisionworks]

Jeff & Chris,

I thought you'd be happy with your lights, and am glad to hear that you are I bored my personal C2 "Glock Light" at the same time & ordered a Malkoff M61 - should be perfect for things that go bump during the night. As you probably know, both the C2 (incan) and the M2 are discontinued according to their website, although the C2 LED is a current production item.

Hard to figure out why the C2/M2 are no longer available, except on the secondary market. IMO, it's one of the best two cell lights available for tactical, home defense, or concealed carry use.

Rat's M3 arrived & a special fixture will be made up for it today. As soon as the fixture is done it will be bored & shipped back to Australia. Should be able to make the fixture today & may be able to bore it today, but will have it finished & shipped out no later than tomorrow. At last count, there were about 15 different welding or machining jobs in my shop, most with a 14 day minimum turn around. As long as there are no emergency breakdown jobs, flash lights are able to stay at the top of the work list & get finished quickly. As I mentioned in a PM to a customer, their light will spend more time in customs than it does being bored

[precisionworks]

Got the fixture finished and got Rat's M3 shipped (as well as his C2).

Interesting little fixture to make. The tail section of the M3 has an outside diameter of 1.000", the mid section has that same diameter, the forward knurled section measures 1.013", and the body then steps back down to 1.000". All the diameters had to be bored to size before the body was split, which involved a bit of head scratching and ciphering. I believe Rat will be happy





Got a PM from a member about boring a M982 (12 volt Weapon Light). To me, it looks a lot like the M3 but a bit longer. I'm hoping the M3 fixture will work for the M982, but will build one if necessary. Pricing will be $48 plus shipping if no special fixture needs to be machined. It may be quite a bit higher if not.

[barry]

Barry,
My Surefire C2-HA (body only) is on the way to you by USPS Priority Mail. I must admit, today wasn't a good day to go to the Post Office! Most branches are closed and there was almost an hour wait at the site that was open. Anyway, the C2 should arrive on Tuesday, July 5th. Thanks.
barry

Also

[precisionworks]

there was almost an hour wait at the site that was open.

Wow, I had no idea ... our small town has one Post Office that is more a social networking site than a government building

The fixture that was machined for Rat's M3 gave exceptional results, both in ease of centering & in centering concentricity along the length of the bore. A new C2/M2 fixture will be machined before Tuesday & it should give superb results for those lights as well. Planning to build one more for the 6P tubes, as I snagged two 6P Defenders yesterday (for boring & resale).

The M4 is another interesting light, one that absolutely begs for a pair of 18650's. Since the M4 is an M3 with an additional 32mm in tube length, boring the M4 should present no particular challenges.

[badkarmaiii]

Barry,
Some questions:
1. Can you bore a U2 Ultra for 18350s?
2. Can you bore to .750" for the Ultrafire 3000mah 18650s?
3. Already answered. I see that you leave a step for the batteries to bottom on.

Thanks,
Lee

[precisionworks]

Can you bore a U2 Ultra for 18350s?

As far as I can tell, the U2 has the same heavy tube wall thickness as the 6P/9P, C2/M2, M3/M4, etc. Every "standard" Surefire, of the dozens I've measured, runs almost dead on 1.000" outside diameter, with the OD at the O-ring groove of .775". That leaves substantial wall thickness after boring & reaming to my normal .738" (18.75mm).

Can you bore to .750" for the Ultrafire 3000mah 18650s?

You're the first person who's asked that question, but probably not the last. The Ultrafire 3000 seems to be the hot ticket today in LiIon. And I just happen to have a brand new .750" reamer sitting on the shelf, waiting for someone to send me their light

IMO, .750" is about as large a bore as I'm comfortable with. That leaves the walls (at the O-ring groove) twelve & one half thou thick (.0125"). There are commercially available bodies that use the same .750" inside diameter, which give me confidence that the walls will withstand hard use & probably some abuse. Not a good idea to run over the light with an M1 Abrams tank, but it should stand up to a HumVee or most anything smaller

Already answered. I see that you leave a step for the batteries to bottom on.

Lee,

Most people don't realize how challenging it is to leave that small step. The boring bar can go in just so far and no farther, but that isn't too hard as the digital readout (DRO) helps control boring depth to within half a thousandth (.0005"). Reaming is a different story, as the reamer is fed in using a calibrated hand wheel. Since most reaming is in the 3" to 4" range of depth, that means 30 to 40 turns of the hand wheel. Doesn't sound too hard, except that only one additional turn wipes out the step

To reduce my anxiety level, a small DRO was purchased just for reaming. That will assure a dead accurate step in every bore.

[precisionworks]

Yesterday was too hot in Southern Illinois for most outdoor activities, but the temp inside the shop is always a constant 68°F - just about the perfect day to spend tweaking all the settings & adjustments on the lathe. Five hours were spent measuring, stoning, honing, grinding, & fitting, so that the machine would produce more accurate work.

Barry's C2 arrived today but it couldn't be bored until the new fixture was first machined & then proved on one of my personal C2's. Machining the Gen3 fixture took about 90 minutes, as the inside dimensions must exactly fit the outside dimensions of the light being bored. If the OD of the C2 measures 1.003", the ID of the fixture must also measure 1.003". Most lights have at least two major diameters, some have three or more, so this is an exacting & time consuming process.

My C2 was bored first, and I couldn't be more happy with the performance & operation of the Gen3 fixture. The light is much easier to dial in & runout can be adjusted down to about .0004" total indicated (+/- .0002"). Barry's C2 was next & his light also turned out very well.

This photo shows my C2 (with the clip attached) on the left, Barry's C2 on the right:



The small lip at the front of the tube is clearly seen in this photo:



Barry's light goes to the Post Office in the morning, and mine goes on the for sale section in the Marketplace - I already have a lifetime supply of C2's

[barry]

Barry,
What can I say? I'm honored. You have done a beautiful job on my C2. The finish is superb. Now I have to decide if I want to actually use the light or put it on display!

For those following this thread, I mailed my light on Saturday. With the 4th of July holiday, it only arrived at Barry's today and he has already finished it. You can see from the above photos he did a wonderful job. Many thanks and .
barry

[beach honda]

Barry M.,

Can I send you my other C2? It's just sitting here waiting for a nice drop-in and some 18650 power.
Let me know when to send\pay.

Thanks,
-Chris

[precisionworks]

Can I send you my other C2? It's just sitting here waiting for a nice drop-in and some 18650 power.

Chris,

My lathe is ready & waiting for your C2

Flash light boring is always in the top spot on my to do list - only an emergency call out job takes priority over boring. My local customer base consists of small business owners, a few larger factories & individuals needing a part to be made or repaired. Most of them understand that their job will take anywhere from a few days to a couple of weeks to complete ... some of the repair work takes 4-6 weeks because many manufacturers carry almost no parts in inventory.

Boring lights fits very well into my shop schedule. When a light arrives, it can usually be started & finished that same day & shipped back the following day.

My C2 "fixture development light" is now listed in The Marketplace, complete with lanyard and batteries:




This view clearly shows the lip at the forward end of the tube:



Another view of the lip from the front:


I don't know how many members are into photography, but those that are may find the last two photos of interest. The photo directly above is lit by fluorescent ceiling lighting & shows cool color temperature. The photo above that has a supplemental 500 watt halogen bulb pointed upward for ceiling bounce fill lighting - much warmer color temp. Exactly the same piece of fancy hard maple in both photos, but they look totally different.

[precisionworks]

A few people have written about the cost of boring the A19 extender. The cost is $10 when the A19 is bored with a light or $20 when bored by itself.

I have no idea if anyone is interested in a bead blast finish for their light, but some people really like it. Below is a photo from the sales thread about the Pocket Rocket 8, and the upper light is bead blast aluminum, the polished one just below it is titanium:



I received a titanium light that looked exactly like the middle one in the photo above. Did not care for the finish at all, even though the light is a killer (XM-L with 1x18650). Machined up a pair of press fit Delrin end caps that would "mask off" each end & put the light into the blast cabinet. Titanium blasting produces a really cool spray of pure white sparks as the high energy glass beads strike the surface. Here's the result:







Glass bead blasting is $20/light in aluminum, $30/light in titanium. To reach that price point, you must fully disassemble your light, remove the clip or lanyard, and thoroughly clean the internal & external threads of all grease. After the light is blasted, I will blow off all parts with compressed air which removes most of the glass bead material, but the threads will still need final cleaning with a soft cloth, Q-tip, sharpened wooden stick, dental probe, etc. The threads & O-rings will need to be re greased before you assemble your light. If you prefer that I disassemble your light, blast it, fully clean it afterwards and lubricate the threads & O-rings, please add $100 to the price listed above.

I was fortunate to have the use of a large commercial bead blast cabinet ... until my friend sold his business This service is no longer available.

Stone washing is now available instead of bead blasting. A big advantage is that this is done in house & I retain full control of both the equipment & the process.

[barry]

Barry,
My freshly bored/reamed/honed C2 arrived safely in the mail on Friday. I will not bother with a photo; there's no way it could match the one you already included in post number 70 in this thread. By the way, I have some 18650 Ultrafire 2600mAh cells that I bought earlier this year (0.733" max diameter). They were too tight in Oveready bored Surefires and Malkoff lights, but fit very nicely in my new C2. Thanks. You did a truley professional job.
barry

[precisionworks]

Barry,

I'm happy that you are pleased

I have some 18650 Ultrafire 2600mAh cells that I bought earlier this year (0.733" max diameter). They were too tight in Oveready bored Surefires and Malkoff lights, but fit very nicely in my new C2.

I have no idea what inside diameter is used by any other boring service. My normal finished diameter is between .738" & .739". I have some commercial tubes (not Surefires) that run as large as .750", so even that number should yield a good result as long as the centering of the tube in the lathe is close to 0-0, and as long as the bore of the tube is concentric with the outside diameter.

Quite a bit of set up time is spent dialing in the center of the tube. When there is no more than .0004" of total indicated runout on the bore, I move the indicator to the outside of the tube & check concentricity. As long as the bore is dead on (or at least under half a thousandth of an inch TIR) and as long as the outside is concentric with the inside, the walls will finish out at a uniform thickness.

There are some fat cells available, RediLast & UltraFire being just a couple of examples. But it's no problem to finish at a diameter that works with these fat cells if enough time & effort are spent during setup.

If you ask any machinist to allocate an 8 hour workday into material prep time, machine & part setup, and actual time in the cut, the results read like this:

Material prep, Machine & part setup = roughly 6 hours (75%)

Time spent in the cut doing actual machining = about 2 hours (25%)

Those are numbers often seen is a job shop like mine, running manual equipment, and working on lots of different jobs. In a CNC shop, running the same part all day long, machine utilization time may run 80% or more.

[precisionworks]

Some members mentioned that they like to see machine work, and these next photos show the fitting of a tailstock DRO (digital read out) to the lathe. Before starting on light boring, a DRO was never badly needed - to advance the tool 1.000" meant turning the feed wheel 10.0 times. Most days I can count to 10 and not lose track, but the reamer has to be run in 3" for a 2-cell light, 4" for a 3-cell light & 5" for a 4-cell light - which means counting 30, 40 or 50 turns without missing a single turn. Go in one turn too far and the retaining lip is toast, turned into small shavings The DRO gives me great peace of mind, eliminates reaming too far, and it a welcome addition for boring lights.

First job was to determine the position of the DRO & mark out the holes:



Used a Delrin spacer to lift the scale about .062", as there is little clearance under the reader head:



Drilled & tapped the two mounting holes by holding the tailstock in the milling machine vise. Used M4x0.7 cap screws, for no particular reason except that there were a few in the parts drawer along with a brand new tap:



Mounted the scale to the TS (tailstock) and checked alignment:



Looked around the shop for some flat stock to make the linkage and found some sheet brass, .062" thick. Wanted to use aluminum, but had only .125" thickness & did not have room under the reader head to use that. Cut the brass sheet with the Delta woodcutting bandsaw, then drilled two mounting holes for the 5-40 cap screws (the back of the Mitutoyo DRO head is already tapped for 5-40):



Scale show with TS ram in the fully retracted position:



Shown this time with the TS ram fully extended:



Started to make the ram collar with a piece of 6061 flat bar, 3" wide & 1" thick. First op was to face both sides flat & parallel to each other:



A central hole was then drilled & bored slightly larger than the shank of a #4 Morse Ta[er. Next came the counterbore, shown here with the lathe turning at 700 rpm (frozen by flash):



The micrometer showed the OD of the ram at 2.1655", and I wanted a size-on-size fit. The digital caliper was used to rough the bore to size, then the Starrett 123 Master Vernier Caliper was used for a dead nuts fit.



Bore & counterbore are finished, and the fit is so close that the part has to be pressed on by advancing the ram forward against a Delrin bar



The Delrin spacers that were used to raise the scale really bothered me, so I cut & drilled brass stock of the same .062" thickness:



The block was milled down a little at a time until the top was dead level with the underside of the brass linkage:



Back to the mill to drill and tap for the three grub screws that secure the collar to the ram & the small screw that attaches the linkage. A Balax Thredfloer forming tap is shown here (it does not cut the metal, it displaces it inward & outward):



Mounted with ram in the fully retracted position:



And in the fully extended position:







A much more involved job than I first imagined. Estimated this at a total of 4 hours, took 10 hours, so my estimate was right on

After verifying correct operation, the entire assembly was removed & all the tapped holes were blown out with brake cleaner, using the plastic straw that comes with each can. Compressed air was then used to blow each hole dry and Loctite 290 thread locker was applied before reassembly.

[beach honda]

dang! that's just pro!

-cB

[precisionworks]

that's just pro!

Thank you!

I know the lathe work would take no more than 15 minutes on the Haas CNC at work, plus another 45 minutes of milling on the Bridgeport. It kills me to know how quickly these could be knocked out, if made in any kind of quantity (like a dozen or more).

My wife came home this afternoon and asked what work had been done in the shop today. I proudly showed her the DRO. Her response was predictable ... "That's all you did during the WHOLE day".

Can't live with 'em, can't live without 'em

[precisionworks]

G Adams ... your C3 is done & ready to ship - please check your PM's

[precisionworks]

For everyone who has a U2 and wants to run an 18650, or for those who would buy a U2 IF it could run an 18650, your wait is almost over

My "organ donor" U2 was purchased on The Marketplace & arrived today. When Surefire designed & built that light, they made it to withstand Armageddon. The wall thickness at the O-ring groove is .013" thicker than any other SF tube that I've measured so far. A standard SF will have a wall thickness after boring of .018"-.019". The U2 walls will measure .031"-.032" ... which is near the thickness of an unmodified standard SF tube. The U2 is a tank, most likely because it was designed as part of a DARPA project for the military.

The challenge with the current U2 is that a stainless steel insert has been press fitted & bonded to the rear of the tube. There are two ways that I can mod the tube, one costing $40 and the other costing $56. The U2 & Kroma can be bored with the stainless steel insert left in the rear of the tube, meaning batteries must be front loaded, for $40 + shipping. If you want the option to rear load the batteries, the insert is removed & the tailcap is shortened but the cost is $56 + shipping because of the difficulty involved.


Turn around time on the U2 will be the same as any other light that arrives - typically 2-3 days.

[LE6920]

This has been an interesting thread to follow. As someone who appreciates fine craftsmanship, you do an outstanding job!

It is very informational as well!

[nbjly]

Since you can now do U2's, I'm thinking you could bore a Kroma as well?

[precisionworks]

very informational as well!

Thank you very much. Machining is a mystery to many people, and perhaps the descriptions & photos help make sense of what happens to your light when you send it off for modding.

I'm thinking you could bore a Kroma as well?

Probably so ... I've never so much as held a Kroma in my hand, much less dimensioned one out. There is a strong family resemblance, with the most noticeable difference being the head ... but that should not affect boring of the light. I believe it can be done, but I will pay return shipping to you if it cannot.

Here's the start to finish procedure on my U2 ...

The little stainless steel insert that poses such a big obstacle. The light cannot be bored unless the SS insert is removed:





Notice the very thick walls at the head end of the U2 ... almost looks like a piece of pipe:



Measuring the inside diameter of the tail end shows .747" after the SS insert was removed:



Measuring the inside diameter of the head, just behind the LE, shows .745":



Since both the tail & the head are awfully close to .750", and since I have a brand new reamer sized at .750", that will be the dimension that the U2's will be bored to.

The spring on the back of the LE sits down in a shallow well, and the spring itself is short. For that reason, no lip will be left in the U2 tube, so the battery can come as far forward as possible:



The tube was fixtured in the 4-jaw chuck on the lathe & centered up. First step was boring out to .740", second step was reaming to .750". Photo below shows the finish left by the reamer (which on its own isn't bad):



The next step is ball honing to smooth & refine the finish:



I was certain that removing the SS insert would cause the tail cap to bottom out against the clip cover without making contact with the switch. Measurements showed that the tail cap needed to be shortened .030". A 30° bevel was then machined so the tail cap would slide smoothly over the O-ring:



The drawback to facing off the tail cap is that a tiny edge is visible if the light is just right. I used a small light to get a reflection from the edge & make it stand out as much as possible:



Other than that, this U2 looks factory stock ... but packs a BIG surprise inside

[beach honda]

Very nice Barry!

I only wish i had that kind of precision in just ONE aspect of my life, much less my job\hobby! Outstanding! Great pics too!

-cB

[precisionworks]

Received a request to bore a Thrunite Neutron 1A, which normally takes a single AA cell. The customer wants to be able to use an AW17500, and also be able to use a regular AA:



Most of David's lights are thick walled and the 1A Neutron is no exception. For this job, having a thick wall to work with makes all the difference:



Every flash light boring job is started by determining the thinnest part of the tube. The 1A has three grooves that all measure .7175" - .7180".



All the available literature on 17500 cells indicates that their nominal diameter is 17.0mm and the max diameter is 17.5mm. My boring target is 17.526mm, just a fraction larger than the largest 17500 cell. 17.526mm = .690"

The reason for sizing so closely is that the difference between ID and OD needs to be at least .025", which will leave the walls at .0125" thickness. By stopping at .690", the walls will be .013" thick, which is the thickness of some commercial tubes.

The rear of the tube is held in a 5C collet. The collet is almost never used for light boring, as most lights have a longer length to diameter ratio. The 1A is short enough that the collet provides secure grip & near perfect centering. Run out (on the indicator face) shows .0002", and this same reading was obtained inside the tube and at the chuck end of the tube:



Set the speed to 1000 rpm and the auto feed to the finest setting. Took very light cuts because of the delicate nature of the chucking. Photo below is with the light spinning, frozen by flash.



The tube was slowly brought to final size by taking a number of spring passes (additional boring passes taken without moving the tool any deeper).





Final bore size is on the money at .690". The micrometer reading is .015" past .675", for a total reading of .690".

[badkarmaiii]

Barry,
Wow! Your work on that Neutron looks great! I really look forward to seeing the final product with the total package of enhancements for that lucky customer!

Thanks,
Lee

[precisionworks]

As Paul Harvey used to say, "Here's the rest of the story"

Spent the entire day in the shop on breakdown work. When I picked this chain hoist up from the owner & asked when he needed it back, his reply was "yesterday". Hung it from the overhead air hoist and went to work. Four hours later & it's good as new.



Delivered that 172# beast & headed back to the shop for real work - lights, that is. Started with a stick of 1.5" Delrin:



Turned it down to just under the bore diameter. Wanted to hit .6880" (2 thou clearance) but got pretty close at .6879":



Slipped the light tube over the spacer shaft to check for fit. The spacer has to be wiggled on, but once in the tube it slides smoothly:



Drilled the hole for the copper post with a 3/16" drill (.1875") and verified with the mic that the hole was on size. Drills often drill larger than marked size, but this one got a fresh grind right before use:



Chucked up the C101 and turned it down to the diameter of the drilled hole +.004", for a tight press fit. C101 is a bear to work, not at all like aluminum. Machinability rating is 20, compared to a rating of 100 for brass alloy 360:





Cut off the spacer & pressed the post into the spacer with the top projecting more than the bottom:





Slipped a new SF CR123 into the tube. SF bores their lights to .692", so the .690" bore on the Neutron is just a fraction tighter than the fit of a CR123 in any SF light.



Pushed the spacer in after the battery & the pressure of the spring at the switch is more than enough to let the spacer move up & down:



Lee & I had discusse removing the ano from the threads so the tube could be run forward or backwards, but it works both ways just as is (here shown backwards):



And shown in the "normal" config:



All modes work perfectly either way. My shop built sphere shows 158.33 lumens with a fresh CR123

[precisionworks]

Just a quick note on communication ... the email address in my sig line goes directly to my Android device, allowing fast response to any questions. PM's don't go to the Droid, meaning that it may be a day or two before your PM is seen & replied to.

The shop has been buried in emergency call work for the last two weeks. Logged 65 hours two weeks ago & 70 hours last week, but the pace should (hopefully) return to normal this week. Got a few lights in last week & was able to bore & ship them back within 24 hours.

[rudy]

Just a quick note on communication ... the email address in my sig line goes directly to my Android device, allowing fast response to any questions. PM's don't go to the Droid, meaning that it may be a day or two before your PM is seen & replied to.

The shop has been buried in emergency call work for the last two weeks. Logged 65 hours two weeks ago & 70 hours last week, but the pace should (hopefully) return to normal this week. Got a few lights in last week & was able to bore & ship them back within 24 hours.

In your general settings, you can set it so the forum sends you an email when you get a PM.