7j43kRegular bits, because of the spiral, tend to "dig into" the work.
thanks
greg - Philadelphia & Reading / Reading
Mike noted earlier that his drill bit kind of broke through at the end. And Ed mention being "careful" when drilling.
Regular bits, because of the spiral, tend to "dig into" the work. For many metals, this isn't a problem, perhaps because the chips break off easily, or the metal is soft enough. But, with brass anyway, the digging in can be a problem. As noted in the topic.
This cutting (rake) angle thing really shows up in lathe turning, where you can easily grind your own cutting angle.
Here's an article on rake angle:
https://en.wikipedia.org/wiki/Rake_angle
Ed
7j43kAnyway, they're sometimes called brass bits, but more often called straight flute bits.
what is the advantage od using such a bit for brass? what is the problem with using a conventional bit?
After ruminating about the discussion here I decided to grab a drill and have-at my B&O Q-3b headlight!
Q_headlight1 by Edmund, on Flickr
This is the "before" status.
I popped the smokebox front off. The headlight casting is pretty solid!
Q_headlight5 by Edmund, on Flickr
After some careful drilling at about 200 RPM with a #55 bit, I have a nice, clean bore for the wires that will lead to a little surface-mount LED.
Q_headlight4 by Edmund, on Flickr
Probably a little larger than the hole needs to be but I like to have a little play when I "set" the LED in place. I use canopy cement and when the glue gets tacky I use a battery to light the LED so I can aim it properly before it sets.
The tender lamp is another story. I'm not going to bother trying to drill this little jewel.
Q_headlight2 by Edmund, on Flickr
Also, I'm going to have an auxiliary water tank semi-permanently coupled to the tender so the back-up light would pretty much be for naught anyway.
Q_headlight by Edmund, on Flickr
Regards, Ed
Thought I'd mention that there are special drill bits for brass. You guys have been mentioning about how your bit pops through at the end of a hole.
Anyway, they're sometimes called brass bits, but more often called straight flute bits.
Nowadays, the seem to look like this:
When I worked in a machine shop back in the '60's, we had drawers full of straight flute bits. They didn't look like the above; they looked just like regular drill bits, but with no twist. The above is kinda stubby.
The reason why brass drills are funny looking is because brass is properly cut with what is called negative rake. Which means that the self-feeding of a normal bit is inappropriate.
I doubt anyone here cares that much, but I thought I'd still inform youse guys, anyway.
You can, by the way, regrind a regular bit for use as a brass drill. It ain't elegant, but it works.
The acetylene headlights have a sort of "top knot" on top. And are usually squarish and much smaller than the REALLY early headlights.
Here's a couple:
Alexander produced another book for steam locomotives from 1900 to 1950. The last acetylene headlight I see is on a Reading 4-4-4 built in 1915. In 1914, there was also the Erie 2-8-8-8-2 and the first PRR K4 Pacific.
I would put The Big Change at WWI.
There were also oil headlamps using "Safety Oil B"
Read about them in this interesting test report:
https://archive.org/details/reportoflocomoti00loui
Holding a chestnut mare across the track?! (Pg. 37-38)
Headlight by Edmund, on Flickr
Fascinating.
yes, smokebox
7j43kSo I just looked at the locos for 1888, and found them all sporting acetylene headlights.
acetylene. wouldn't have thought of that.
the headlamp fixture on my engine is square-ish. i'm guessing not electric. I see cylindical headlamps in most photos which are after 1900.
gregc 7j43k when there's a working headlight, they typically drill straight out the back, and then downwards behind the headlight. Two holes. is this how the prototype routed the cable, through the boiler (firebox), or just easy on the model?
7j43k when there's a working headlight, they typically drill straight out the back, and then downwards behind the headlight. Two holes.
is this how the prototype routed the cable, through the boiler (firebox), or just easy on the model?
Not on the prototype. The electrical wiring of a real steam locomotive NEVER goes inside any part of the boiler.
It's just what I see on HO brass locos. W&R comes to mind, for example.
The front section of a steam locomotive boiler is the smokebox. 'Cause it's full of smoke. The rear section of a steam locomotive boiler is the firebox. 'Cause it's full of fire. Easy to remember.
this is an early loco, rebuilt in 1888. i'm curious what kind of headlamps locomotives had at that time, considering Edison only invented the light bulb in 1882.
I've got a neat book by E.P. Alexander called "Iron Horses, American Locomotives 1829-1900". It's a two-page spread for each sample locomotive, with a picture on the right side. And the pages are all dated. So I just looked at the locos for 1888, and found them all sporting acetylene headlights. Acetylene headlights are self-contained, meaning there are no supply pipes. If you haven't installed the headlight yet, you might consider drilling through the bottom of the headlight instead of the back--less wire to show.
Also, in 1888, locomotives did not light their headlights during the day. So, if you don't run your locomotive in the dark, you don't need a working headlight.
i found a few photos showing something coming out the back of the headlamp, but i'm not sure if it went into the firebox or into a presumably hollow handrail as suggested by HNTX.
As I said, nothing goes into or comes out of an acetylene headlight.
What you are seeing is almost surely an electric headlight. Generally, the wiring for them comes out the back, using flexible metal conduit. That goes over to a junction box on one of the locomotive handrails (sometimes with some intermediate conduit and fittings). And back to the cab to the on/off switch.
i have black wire wrap wire (30g) that I could even glue to the boiler if i had too.
Some years ago I use #43 enameld wire for LED wiring. No idea the diameter of the wire. It might work.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
7j43kwhen there's a working headlight, they typically drill straight out the back, and then downwards behind the headlight. Two holes.
I use a small dental burr in my dremel. Very high speed and drill a hole in the housing and then into the boiler. I use LED's,so magnet wire will work. You have to be careful when you thread the wire through holes. After getting the wires where you want them I put a drop of caulking in the holes around the wires, this will hold the wires and provide some insulation.
Pretty much all brass steamer smoke box fronts come off like he shows, might take a little prying or a light tap from behind with a small micro punch and a tack hammer thru the length of the boiler to free it. I also put the headlight in my jewelers vise and using my cordless drill and a good sharp bit drill thru the back, to slow and it will really grab when it breaks thru. I find a good fast metal cutting speed, which is slower that drilling thru wood is best. I now have a small bench top drill press and this makes it much easier to control the bit and speed. I then use my pin vise to make the necessary hole in the boiler shell to route the wires. I am analog DC, so no worries about blowing up decoders. A MV lense with the foil backing removed works for a lense, as does some acetate materal cut to shape and glued in. I leave the inside of the headlight in shiny brass, gives a nice golden glow to the beam, espically with using a regular bulb. I am anti LED in most steam headlights, prefering a good old bulb. But that is my personal preferance. Mike the Aspie
Silly NT's, I have Asperger's Syndrome
I have faced the same dilemma several times on various brass HO locomotives that I have painted and installed decoders in. Sometimes I'm lucky that there is a "cored" replacement headlight from Cla-Scale or Precision and I'm able to replace the stock headlight. Still, routing the wires past the lead boiler weight can be a challenge. I try to use a small piece of heat shrink tubing as a loom to help prevent the wire from being pinched inside the boiler.
Presently I'm working on a B&O Q-3b and the more I look at the project the more I conclude that the headlight will get a MV Products lens. Same with the vanderbilt tender which is nearly impossible to get into the tank to even route any wires.
Then there is the engine-tender wire connection which, if wiring a headlight now jumps up to five wires. As George cautions, almost all brass steam uses the locomotive chassis and in turn the whole boiler as a pickup for the right rail so everything is "hot".
I have been successful in drilling a solid headlight for running headlight wires but it can be a challenge. I always remove the headlight from the locomotive as the drill will have a tendency to grab, especially with brass. Trying to drill with a pin-vice was not working, I used a very slow RPM cordless screwdriver fitted with a tiny chuck from Micro-Mark holding the casting in a jeweler's vice.
In some cases, like this Pennsy B6, the whole smokebox front can be pried off making the job much easier.
IMG_9496_fix_B6sb1 by Edmund, on Flickr
Good Luck, Ed
FWIW, on brass steam locomotives, where the headlight is on top of the smokebox, ahead of the stack, when there's a working headlight, they typically drill straight out the back, and then downwards behind the headlight. Two holes.
Whether DC or DCC, you don't want the wires shorting to the body--nothing good can come from that. So, after installing the headlight, check if it lights up. Then also check to see if there's continuity between either wire and the body. If there is, fix it. If not, consider putting a teeny blob of epoxy in each hole to keep it that way.
Oh, yeah. Also do what it takes, resistor-wise, to make sure the bulb/LED never burns out. So's you don't have to do this again.
If you are thinking of DCC for the locomotive, be careful of making the brass body a ground path. It could fry the decoder
George In Midcoast Maine, 'bout halfway up the Rockland branch
Headlight wiring on steam locomotives was routed outside of the boiler jacketing, usually alongside the hand railing if the generator was close to the cab. On some engines, the hand rail itself served as the conduit for the cabling, especially on streamlined engines.
i recently obtained an OMI brass steam loco. It does not come with a headlight. My problem is that there is no hole for wires between the brass headlight opening and the interior of the shell.
the headlight fixture is forward and above the boiler. I believe i could drill an angled hole through the back of the fixture into the boiler. But i wonder if headlights were acutally wired. Wouldn't any headlight cables be routed outside the boiler?