I keep braking my draw bar up by the nut. What kind of pin should I be using to help prevent this?
Also next time I need to build another one sense its getting expensive to buy them. what is the best type of metal for the drawbar to buy for one?
Thanks for your time guys!

This might sound silly, but I don't think they have to be that tight. I can't ever recall breaking on myself.

quote:

Originally posted by speerchucker30x378:
This might sound silly, but I don't think they have to be that tight. I can't ever recall breaking on myself.

What he said. I've got one I made of common ol' 1018 that I've used for years. It pulls a B&S 9 tool holder or collet up as it should. Not overly tight, B&S tapers lock well, anyway. The only reason I made one was because the original was long lost when I aquire the mill. R8 taper isn't 'self locking', but I've never known one to break, not even with a power draw bar. I have had to chase the tool holder end with a die a few times. What kind of mill,, what taper?

Thanks guys.
I've been making it tight because the bits have been sliding. But I think its because my bits are old and worn. I despretly need new ones. I have a few new bits on the way in but I may get the ones I have sharpened. I've talked to some local guys, but I dont think they've sharpened endmills.

I'm gonna go out on a limb and say that you're trying to hold your mills in an R8 or a Van Norman collet. While they are great for centering and relatively easy removal they are not the tightest closing collets that were ever invented. What you might want to consider is buying a set of ER32 or ER 40 collets and a chuck to fit your mill. They close a lot harder with less effort than the old style collets. They also save a lot of wear and tear on your mill spindle taper because the chuck stays in the mill during tool changes. I use the ER32s in my mill for general work and the ER40s for shanks larger than 20 mm. They hold like the dickens !

Just a thought.

ADD NOT:
You also won't have to play Tarzan all day climbing all over your mill to change the tools. All that monkey business is right in front of you at eye level with double closing Regofix ERs.

I'm stepping out on a limb but I'd bet I have tightened and loosened more draw bars than most

Not to metion using the same 3/4" box end wrench as a hammer to drive the collet/chuck/holder out with the draw bar

Do they have to be tight? Funny.....yes they do or cutters will pull down and drills will push up

If you don't care about accurate depth run it as un-tite as you want but for serious work tight is required

If your socking a 1" Krestcut through 4" of 4140 you need a solid holder not a collet....then you use your 3/4" wrench to drive the table......not the handle

You gotta feed that cutter so it steams!!!!

Original Bridgport solid non-pinned drawbars are 100x better than pinned imports

Before I bought another of your 2 piece draw bars I would weld the 2 together with Brutus or 680

But tight is required for all my daily knee mill work especially all inserted carbide cutters and large drills up to 2"

A horse wears a bit in his mouth

mills run cutters and drills

I'm always a bit carefully with the word "tight" now days Ted.
I had an apprentice mention to me that he had been milling something or another but for some reason the cut was not parallel. I had a look and it turned out that he hadn't tightened the vise down enough after truing the dead jaw and the cut had pushed it over a bit. I must have been having a bad day because I gave him hell and told him to make sure those fawkers were tight. Well he got it tight alright and bent the hell out of 4, five inch pallet clamps. LOL

Hmm lets see.

My 1986 Lagun FVT-2 mill had its second draw bar give out last year, those are one piece.

My 1987 Sharp SP-2 mill is on its third draw bar. Have been getting about 5-6 years on the pinned bars, and I have been known to sliver solder the joints back together and run it a few more years before the threads wear out.

Sounds like it is time to go to an Weldon type end mill holder instead of a collet, and also buy some new end mills.

JW

Did you ever have a endmill spin in your collet? You may have spun a burr on the inside. Also a R8 is not a cat 50 in a K&T. Work accordingly.

I tried a ER40 holder in a Haas vf-1, then I went directly back to a tool holder. Just not ridgid enough. Tool holders for milling cutters, sometimes a collet for a drill but, usually the Albrecht drill chuck. ER colllets do work OK for holding drill bits in the VF-1. Manual mill/VF-1,,,,, apples to oranges.

quote:

Originally posted by speerchucker30x378:
I'm always a bit carefully with the word "tight" now days Ted.
I had an apprentice mention to me that he had been milling something or another but for some reason the cut was not parallel. I had a look and it turned out that he hadn't tightened the vise down enough after truing the dead jaw and the cut had pushed it over a bit. I must have been having a bad day because I gave him hell and told him to make sure those fawkers were tight. Well he got it tight alright and bent the hell out of 4, five inch pallet clamps. LOL

Toe clamps.....if he bent them

lesson #2 shold have been max forward bolt placement towward clamped object

I tighten head bolts and ram/collum bolts as hard as I can pull a standard 3/4" box end/hammer wrench

My vise bolts get even tighter treatment

Dont forget when pushing a .013/.018 chipload put lube on the angle of your holder

Fretting will still occur and a sharp blow from a soft hammer is almost always required to break a heavily used holder loose

Solid R8's are also the way to go with air draw bars....they are nice but not tight enough

I use a standard wrench to tighen the draw bar. I have had issues with the mills spinning.

This hole knee mill needs to be rebuilt. Badly. Its an 1981(same year I was born) made by Machine World in Tiawan. I cant find anything about the company that made it.

I needs many parts replaced too. I've broke many mills because it will grab and walk to take up the slack. Tighting the gib helped allot but it will still grab and jump from time to time. Replacing those bits can get expensive.


I will upload some photos later on. My hole shop will be getting a make over over this winter. But sadly as a disabled vet I dont have much cash to get newer machinery. I can still do nice work because I've learned how the machines work and what issues they have.

Thank you for all the help and your time guys!

I have seen a huge proformance differance when using cutting oil. HUGE!

quote:

Originally posted by ted thorn:
Dont forget when pushing a .013/.018 chipload put lube on the angle of your holder

Fretting will still occur and a sharp blow from a soft hammer is almost always required to break a heavily used holder loose

Solid R8's are also the way to go with air draw bars....they are nice but not tight enough

quote:

Originally posted by James Kain:

I needs many parts replaced too. I've broke many mills because it will grab and walk to take up the slack. Tighting the gib helped allot but it will still grab and jump from time to time. Replacing those bits can get expensive.

You're feeding the material into the pulling side of the cutter. What you're doing is called climb milling and it's a no-no with non ball screw machines. Yes, you can get away with it with light feeds and tight gibs but you are just asking for trouble. With that equipment you should always feed into the pushing side of your cutter. Even with brand new machines without ball screws, climb milling can be problematic. Stay away from it.
When I first started running machines 35 years ago climb milling was just simply unheard of and if someone caught you doing it you would find yourself back, pushing brooms again pretty fast. Old style machines still have to be run the old fashioned way.

quote:

Originally posted by James Kain:
Ive seen a huge proformance differance when using cutting oil. HUGE!

quote:

Originally posted by ted thorn:
Dont forget when pushing a .013/.018 chipload put lube on the angle of your holder

Fretting will still occur and a sharp blow from a soft hammer is almost always required to break a heavily used holder loose

Solid R8's are also the way to go with air draw bars....they are nice but not tight enough

Cutting oil.....I remember the smell.....haven't used it in years

Blasocut coolant or Castrol coolant for most cutting and drilling at our place 8 to 9% coolant to H2O

Climb cutting is a skill you can master and is very very easy.....use your table locks

Check into re-grinds

Get your cutters sharpened

Been running mills for forty years. Never broken a drawbar, never even seen one broken. Never had an end mill slip. Maybe I'm doing something wrong?

quote:

Originally posted by Toomany Tools:
Been running mills for forty years. Never broken a drawbar, never even seen one broken. Never had an end mill slip. Maybe I'm doing something wrong?

You have never had an end mill pull down or slip in an R8 collet.....hmmmm

30 years of filling 55 gallon drums with chips I must be doing something way wrong

I've had disposable insert cutters slip quite often in R8, Van Norman, 5C and Morse taper collets. The occasional one in ERs too. As far as carbide and HSS cutters, I'd rather just break those fawkers off and be done with it. 99.9999% of the time when stuff like that happens I've done something silly. But I've never broken a drawbar. Wore off the threads on a few, but never broken one.

Some days you just have to make your own entertainment.

Try sandblasting the shanks of your bits and endmills. Protecting the business ends of course.

conventional for most ruffing, climb for finishing. In a pocket, conventional finishing can also get exciting in a hurry.

I made one out of stress proof 1144 3 years ago. Still going strong.

I've cut a lot of jackshafts and tie ends from that stuff. It's very tough material and doesn't require heat treatment. Very expensive crap though.

Spearchucker
I have a K&T #4 built in 1965 that has a backlash eliminator to be able to climb mill.
So someone back in the day knew about climb
milling.
Don't know why anyone would buy a Bridgeport.
Unless you don't have the room or power. A useable K#T can
be had for about the same price.
Every part can also be found easily.

I have a 9X32 column mill that works as a good drill press and a HauDong knee mill clone. The head is made in Taiwan but I dis-remember by what firm. It's just a basic 9X50 Racer / Bridgport / Lagun knee mill. I can also climb mill by setting up the gibb screws and once in a while I do if I'm octogoning barrels with shell mills or some other specialized chore. (you can with most any mill) But I'm not in a production shop anymore so I seldom do.

For someone that's just starting out, just making the odd amateur cut or has a limited tooling budget I seldom recommend climb milling unless it's a ball screw machine with no backlash. And in the bad old days when the really good Niagara or Putnam tooling was about as good as the cheap Chinese crap of today, I just never saw it practiced to much.

I have worked on Kernys, cincis and many other big horizontal and vertical mills but for 90% of the gunshops I have been in it always comes down to semi portability, no space and no three phase power. I see a lot of those big mills just sitting out in the rain around here because no one has the power to run them. Single phase machines that will fit in an idiots garage however are like gold and cost twice the money!

Just as an example check this out: $2500 Canadian is about $2000 USD right now.

http://www.kijiji.ca/v-busines...hNavigationFlag=true

There is simply no use for machines like this. Machine shops don't want that old crap and hobbyists, farmers and small shops don't have the power requirements or space for them.

Spearchucker
Yep, ain't that the truth.
I have a K&T #3 universal table combo horizontal and vertical with a two way
head and a 25" Leblond lathe with a 3" hole that
I've been trying to give away for about a year.
Have no more room to work!
Oilfield is bad right now so nobody local needs them.

I had one of the local tool salesmen coconuts in here the other day trying to sell me a Cincinnati 24" shaper. I guess he heard I had been cutting a lot of key ways in sheaves for a local electrical company. I have a 4 inch slotter but since the salesman's outfit was just a few blocks away I went down and took a look at it. Outside of the fact that it had been used once 50 years ago before it was parked it was in great shape. The 3 phase motor could be easily stripped off and scrapped and for $500 I could toss on a pretty skookum single phase 220 motor that would get it humping just fine. I was thinking out loud and finally said OK $500 for the motor and $500 to move it to my shop: "How about $500, does that work for you?" He was all smiles and told me that he really shouldn't give me such a good deal, but I'm apparently now his buddy, pal and best friend. He asked if it was going to be plastic or cheque and I told him that I didn't take plastic but he could give me a cheque. He seemed to have gotten a bit confuzzled and didn't seem to understand that he was supposed to PAY ME $500 to take it away. Not the other way around. I guess he isn't my bestest buddy, pal or friend anymore but I'm now getting emails on other junk they have for sale.

I bought a shaper once at auction. I left
the machine and took the vice. Don't make
vices that that any more.
I have a K&T built in 1952. It has a plaque
on it that reads "in 1952 this machine cost
$24,895.00"
Wonder what that would be now.

That would work out to approximately $234,000 when adjusted for inflation. If shop rates were $6.00 per hour, (which I suspect is pretty close) they would be jobbing out the machine at $2 per hour which would give a return on the machine in 6-1/2 years which is pretty close to what it is now with a 1/4 million dollar CNC mill.

quote:

Originally posted by James Kain:
I keep braking my draw bar up by the nut. What kind of pin should I be using to help prevent this?
Also next time I need to build another one sense its getting expensive to buy them. what is the best type of metal for the drawbar to buy for one?
Thanks for your time guys!

Get some 1144 Stress Prof and make one, Mill a square or hex head on the end. Choke up on a 3/8 ratchet and that's as tight as you want.

Wallyw

Is the key in the spindle in good shape?

There is a cute trick I do to save money and time on those bars Wallyw. Buy the material to the OD of the thread and then buy a coupling nut (those two inch long beggars used to join two stud bolts) with the same internal thread OD as the OD of the shaft that you have threaded for the collets. Drill the out the threads to leave the ID of the nut the same as the OD of the bar and simply silver solder the nut on to the new shaft. It's easy and quick and the silver solder is plenty strong enough over 2 inches. That way you don't have to buy a 3/4 inch chunk of tool steel shaft and turn 50% of it away.

quote:

Originally posted by speerchucker30x378:
There is a cute trick I do to save money and time on those bars Wallyw. Buy the material to the OD of the thread and then buy a coupling nut (those two inch long beggars used to join two stud bolts) with the same internal thread OD as the OD of the shaft that you have threaded for the collets. Drill the out the threads to leave the ID of the nut the same as the OD of the bar and simply silver solder the nut on to the new shaft. It's easy and quick and the silver solder is plenty strong enough over 2 inches. That way you don't have to buy a 3/4 inch chunk of tool steel shaft and turn 50% of it away.

I'd have done it just about that way Speerchucker except I had some Stress proof handy.

In my experience bits that slip in a collet indicate a loose collet. Shouldn't need to tighten draw bar that much. I've got R8 set in 32nds so usually get a good fit. If not I will cut a piece of file folder or shim material to get the fit. R8s won't close on much more than 0.002 under.