Camshaft gun drilling source?

I used to know a guy here that made barrels for reproduction muzzleloaders (haven't seen him in over 20 years). Try a local gunshop. The gunsmith that they use might have a setup for doing it.

 

How long and what size hole? Do they really need to be "gun drill' straight?

I would think with just a normal lathe you could drill from one side, flip it round and drill from the other no? Just need to buy a long enough drill or make a shank extension depending on diameter.

 

you doing the crank too? If you are going this far....

 

On some camshafts that are hollow, some aircraft for example, the lobes are flame brazed onto hollow bar stock. That would allow you to use a much harder steel alloy on the lobes, and I believe thats why it was done on aircraft.

 

Pitty we don't live on the same continent ,I've got a 2,5m with 100mm spindle bore in my shop you could use that anyday you wanted .How big is the billet to get the lift you want .It was posted somewhere else that the 430 's(or one of the later Fcars ) lobes were press fitted onto the shaft ?

 

ROMAO!

 

There's a part I do that's got a drilled hole with depth = 70x dia in some fairly hard drive shaft mat'l . .. you should be able to get a guy with a lathe to do that for you . .. I think mine has a 2.5" thru hole but you're not just 'round the corner.

 

It's a part I do on the mill . . . it's pretty straight but the drill is only .125" . ... still the depth/dia ratio you're talking about. I'd go from either end and let them intersect in the middle.

Dragging the tail stock in and out will make a man out of you .

Edit: when I say pretty straight gut feeling is within .01-.02"

 

mk e,
What kind of a drill bit are you planning on using?

That kind of depth/dia ratio seems to call for a gun drill, eg:
http://www.wim.hk/en/news_detail.php?id=53
http://www.sterlinggundrills.com/deep_hole_gun_drills.shtml

 

Deep drilling shafts has always been tricky business for me (I don't have a proper gun-drill). Without a hollow drill I'm not sure how you'll get coolant much past a few inches inside the hole much less keep chips clear and keep it even close to centered.

Considering everything on your plate this might be one thing to outsource. It might not be really expensive to let someone else drill the blanks.

 

http://www.grovergundrilling.com/quote_from_grover_gundrilling.shtml

Worth a shot?

 

Certainly looks like they could handle it.

 

Also bore and chamfer each end after drilling and you'll have your centers back atleast for the length of your boring bar.

 

Yeah I used to think that . ... . paralysis by analysis . .. being an engineer I sent my parts out for gun drilling . .. then someone with 40+ years manual machining experience started working for me and told me to go in the office where I belong and order a long drill . He's forgot more than I know about cutting metal . .. . but ask him to troubleshoot something electrical .

Something else to keep in mind. .. careful you don't heat treat/quench it with coolant down inside the oil . .. run it slow and maybe use tapping oil . .. the large bar stock will help as a heat sink . .. might want to do a few inches at a time from each and let the bar cool for heat sink purpose. Not a problem with CRS or aluminum but I think you're using alloy.

http://www.shoprutlandtool.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&catalogId=10001&langId=-1&productId=38825

1/4" dia 16" long drill to get you started . .. old faithful McM only go to 12" . .. now get to work .

Sean

 

Hey Mark,

There's a gun drilling specialist in the Philadelphia area. I'll get you some information tomorrow. They do DEEEEP holes.

I've been so busy that I got out of the habit of visiting here. Probably missed out on some great bench talk.

Had my supercharged 308 at the Penn-Jersey "Spring Fever Run" yesterday. The twisty roads and the car were a blast! Somehow it tore a fairly new C.V. boot.

Wil