I have been trying to make my own quarter elliptical rear spring setup. I have built all the brackets and everything looks great but I can't find a bit that will drill more than one hole before burning up. I checked the 4x4 sites and the only "secret technique" I could find was to use masonry bits but the two different ones I tried woudn't even touch it. These setup seem fairly common so what are you guys using to drill through springs?
Go slow, use lots of pressure, and try that stuff called "Cutting Fluid". They call it that for a reason.....
I've used the standard carbide bits I got from work, kinda pricey if you buy them. You might check with Den-Col over on Wash. and I-70 but don't know if they sell retail.
I'm using cutting fluid and a drill press. I have succeeded in drilling five holes 1bit per hole. I have varied speed and pressure. I have so much money in bits now that I am afraid to even try another kind. I like the idea of punching the holes but I'm not even sure who would do that. The sellout is to buy the expensive posies kit. If anyone else has suggestions I'm open to them. Time is valuable and I've burt up half of my three day weekend on this!
what do you mean you are going through bits? like you snap them? you know you can regrind the bit right....
What kind of RPM are you using with the drill? I'll be the first to admit I know next to nothing about these things, but I think you need a decent drill press, a pretty slow RPM setting (500-750 ???), and lots of oil when drilling thick metal. It also helps to drill small holes to start with and work your way up to the final size. Hopefully somebody else can confirm or deny this before you spend any time or money.....
The bits dull out FAST no matter how much pressure or what speed I use. I ground three of the bits but they wouldn't cut after I did it. I admit I don't know how to grind them though and I don't have a bench grinder so I was using a angle grinder. Maybe I just need a bit grinding lesson? That would solve my problem for sure. Do those drill bit grinding machines work? Thanks for all of your help guys!
Cant grind the bits with an angle grinder, I have been where you are, wanting to do a job real bad with what I have on hand. Get a bit grinding fixture at Sears, you will need a bench grinder. Spring steel is tough, as you know. Get the tips sharp and the right angle, then you can repeat the process.
Most people don't realize it, but a drill bit cuts metal better when it's going slower at a constant speed with constant pressure. You really know it's working when you start getting those little pig tails of metal.
Sharpening bits is very easy with a bench grinder. I'm sure there are jigs and what not to help, but find someone to give you a lesson and just do them by hand. You'll never look back. This is one of those essential skills you really need to acquire if you're going to do much of this work. If I knew how to draw on a computer I would make some diagrams to show you what to do, but as I can't I think I would have trouble describing it well enough. Someone will show you. Ask around at the local hardware. Good luck. Pete Oh yeah. Definitely start your holes with a pilot hole...maybe 1/8".
I have been in the spring shop for a lot of years,These several previous posts are correct. sharp drill bit,slow speed and cutting oil.You will go through them like a knife through ****er.
Sounds like you may have work hardened the steel.Good high speed or cobalt should still get through it slow and steady.It may take a few sharpening before you get through it.You could use an angle grinder just clamp it up in a bench vise if you have one.It takes lots of practice to sharpen a drill correct.Even the drill sharpeners are just a good start point.I would thin the center web on the drill bit to help reduce some of the center drilling pressure.Burl.
Well, you can sharpen bits with an angle grinder, but you've got to have a steady hand. I've used an angle grinder to sharpen bits for years, never had a problem with doing it. They might not be dead on angle wise, but they seem to cut every bit as good as new ones. You can control the "bite" angle of the bit with an angle grinder, not sure the bench grinder jigs will allow that.
sounds like sharpening bits by hand is going to take some practice. So do the drill bit sharpening machines work or do I just need to learn the craft?
Use a carbide drill. low rpm [ to figure out rpm, the standard method is by using surface feet. For hard steel surface feet is about is about 35 to 40 sf x 3.82 `/. by diameter of drill, that will get you your rpm. ] don't forget to use oil for lube. And put some wait on drill when drilling that will prevent the drill from chartering and chipping.
Yes, the web gets too thick to cut right. How big a hole are you drilling? Pilot hole first? I do not sharpen ANY drill bit under 1/4 inch, they are too cheap. Practice with someone watching over your shoulder or look at a new bit and try to dulicate it. You should be learning on a bench grinder. They CAN be sharpened on an angle grinder but it's harder to learn. I sure hope you aren't buying junk from Harbor Freight or similar places. Buy a good brand, Greenfield, TRW, etc.. I like colbalt. I drilled a friends springs years ago for teflon ****ons, go slow and constant pressure. Once it starts cutting go with it. Have someone else apply lots of good liverkilling cutting fluid, Tapmagic is my fav.
If you know what your doing you can sharpen a bit that will cut great and last a good while. It took me a while to learn how to sharpen one but eventually I got good at it and can sharpen one in just a few seconds. If you dont know how or dont have anyone to show you, you might want to look into buying yourself a DRILL DOCTOR. They sharpen bits really well and all you have to do is chuck it up in the holder and move/rotate the handle. Only down fall is I think they will only hold a 1/2 drill bit (atleast the ones ive seen). I have one but i rarely use it, I can sharpen one faster than the time it takes to get it out and chuck a drill bit up. I have tried the whole angle gringer deal to, its hard to do esp if you dont know how to sharpen a bit to start with. Get a bench gringer and it will make things much easier. I guess it depends on what your drilling, and it sounds like you are trying to drill some hardened metal. Turn the RPM's down and go slow, use plenty of cutting fluid.
I have a rule of thumb for cutting metals is pretty easy to follow. RPM (of the cutting tool) = the cutting speed of the material x 4/ the tool diameter. or RPM = (CS X 4)/D. Figure that the cutting speed of mild steel is 100, take it down to 80 for spring steel. For a 1/2 drill, it would be (80 x 4)/ .5 which is 640 RPMs. Tips for drill press work, use a vise or clamp the material down to the table. Use a spotting drill or center drill to initiate the hole. Anything over 1/4 in diameter, I use a pilot drill and open it up in steps. If you can find them, go with a ***anium nitride coated drill. They are better on harder materials, better than cobalt. Bob
post a couple pictures of your design. I was going to do the same and had thoughts about drilling the spring steel also...
When I drilled mine I used a small bit first...like maybe 1/8 in. thats your pilot hole...then went up to maybe 3/16 then quarter all the way up to the size I needed. Used WD-40 to keep it cool as it was all I had...just keep the bit from burning up. I only used one of each size bit without having to resharpen and so I guess it worked!
Keep in mind, when step drilling you select a pilot bit that's just barely larger than the web thickness of the next bit. That prevents the bit from chattering and binding.
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