# Boring in the mill with lots of chatter. Ideas?



## Janderso (Jan 19, 2022)

I have yet to be able to bore with this mill. It’s not the mill. I have a 30 taper, I can use the ER40 chuck or the 30 taper holder.
I must be missing something.
I have way too much flex with my options available.
The best I can do is 8” with a short Criterion bar To the spindle lugs.
The boring head is a 2” Shars. The table is locked, the quill is locked, the gibs on the boring bar are tight.
Ideas? I can make this thing sing big time with terrible results.

Heck, my wore out BP with an R8 did a better job.


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## rabler (Jan 19, 2022)

I guess my first thought is have you put an indicator on the business end of the boring bar and tried to move it with finger pressure?  Then working back up the stack to see where and flex comes from?  It does look like a long setup so I'm just shooting from the hip here.


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## DavidR8 (Jan 19, 2022)

Aside from yours being a 30 taper I have the same setup.
I'd opt for the ER chuck if you can push the straight shank on the boring head further into the collet.


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## derf (Jan 19, 2022)

Try changing the angle of your boring bar. Sometimes the attack angle is under the centerline.


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## woodchucker (Jan 19, 2022)

from the picture, it looks like you have the cutter facing 90 degrees to where it should be.
The cutter should be aligned with the heads sliding direction, not 90 to it.

It would be better to be able to enlarge the pics more, just too low on detail.  from your pics this is 90 off


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## mikey (Jan 19, 2022)

I have a couple of guesses:

You have the boring head on a long shank that is sticking about an inch from the end mill holder at the end of your 30 taper. That is a lot of interfaces with a *lot of extension*. Ideally, you want the boring head adapter, the part that screws into or onto the head, as short and as close to the spindle taper as possible. Is there a 30 taper adapter that will screw right into that head?
You are using a long boring bar. It should be as short as the bore depth allows.
As stated above, the tip of the bar is misaligned. The flat on top of the bar should be dead on the axis of movement of the sliding part of the head. If you don't do this, the depth of cut adjustment will be totally inaccurate.


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## MrWhoopee (Jan 19, 2022)

Shorten the shank on the boring head
Shorter boring bar.
Give us a close-up of the grind on the bar.  Those brazed bars require a LOT of grinding to get the geometry suitable for a boring head. As purchased, when the cutting edge is in the right orientation to the boring head you end up with negative rake.


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## jwmelvin (Jan 19, 2022)

mikey said:


> The flat on top of the bar should be dead on the axis of movement of the sliding part of the head.



What’s the best way to do this? I’ve sometimes held a 6” scale on the tool’s top surface, but sometimes by eye.


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## jwmelvin (Jan 19, 2022)

MrWhoopee said:


> As purchased, when the cutting edge is in the right orientation to the boring head you end up with negative rake.



As in, they need additional radial clearance below the edge?


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## Janderso (Jan 19, 2022)

mikey said:


> I have a couple of guesses:
> 
> You have the boring head on a long shank that is sticking about an inch from the end mill holder at the end of your 30 taper. That is a lot of interfaces with a *lot of extension*. Ideally, you want the boring head adapter, the part that screws into or onto the head, as short and as close to the spindle taper as possible. Is there a 30 taper adapter that will screw right into that head?
> You are using a long boring bar. It should be as short as the bore depth allows.
> As stated above, the tip of the bar is misaligned. The flat on top of the bar should be dead on the axis of movement of the sliding part of the head. If you don't do this, the depth of cut adjustment will be totally inaccurate.


I’ll have to do some homework to see if there are shorter hardware options. I could always cut the bar.
Regarding the cutting edge, I just stuck it in to show the length.


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## Janderso (Jan 19, 2022)

MrWhoopee said:


> Shorten the shank on the boring head
> Shorter boring bar.
> Give us a close-up of the grind on the bar.  Those brazed bars require a LOT of grinding to get the geometry suitable for a boring head. As purchased, when the cutting edge is in the right orientation to the boring head you end up with negative rake.


I thought i put the criterion tool in. It has a proper edge, the ones in the kit need a lot of work for sure.


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## MrWhoopee (Jan 19, 2022)

jwmelvin said:


> As in, they need additional radial clearance below the edge?


No, the back rake on top of the carbide needs to be ground. As received, the top of the carbide is parallel to but above the centerline of the shank. When the bar is rotated so the cutting edge is on center with the boring head, the carbide has a negative back rake. 
In this picture the bar on the left is as received, the one on the right has been ground to provide a neutral or slightly positive rake.


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## Janderso (Jan 19, 2022)

jwmelvin said:


> As in, they need additional radial clearance below the edge?


They need to have all the clearance you would see in any normal cutting tool. The brazed carbide tools need to be shaped.


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## Janderso (Jan 19, 2022)

MrWhoopee said:


> No, the back rake on top of the carbide needs to be ground. As received, the top of the carbide is parallel to but above the centerline of the shank. When the bar is rotated so the cutting edge is on center with the boring head, the carbide has a negative back rake.
> In this picture the bar on the left is as received, the one on the right has been ground to provide a neutral or slightly positive rake.
> View attachment 392964


Well done. 
Notice the cutting edge is way off center line on the as shipped tools.
A good example of how moch work they need.
I think my biggest problem is the 8-10” the cutting edge is from the spindle lugs.


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## mmcmdl (Jan 19, 2022)

Too much hanging out of the holder and too small a boring bar .


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## mmcmdl (Jan 19, 2022)

woodchucker said:


> from the picture, it looks like you have the cutter facing 90 degrees to where it should be.
> The cutter should be aligned with the heads sliding direction, not 90 to it.


This too !


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## woodchucker (Jan 19, 2022)

MrWhoopee said:


> No, the back rake on top of the carbide needs to be ground. As received, the top of the carbide is parallel to but above the centerline of the shank. When the bar is rotated so the cutting edge is on center with the boring head, the carbide has a negative back rake.
> In this picture the bar on the left is as received, the one on the right has been ground to provide a neutral or slightly positive rake.
> View attachment 392964


I have no trouble with mine being straight. It cuts perfectly well.


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## Janderso (Jan 19, 2022)

I have some off shore tools but mostly Criterion and Bokun brand.
In the last pic is another example of how much work is needed just to get the carbide cutting edge to the centerline.
I’ve tried just about every tool in my box but the excessive distance is causing unbelievable chatter.
Tool on centerline, parallel with the adjustment screw, as short as possible, etc.
I thought it might be spindle bearings but the runout is within factory specs.

I sure would like to see your boring head set up!


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## Winegrower (Jan 19, 2022)

I have never had to grind my import boring bars, you just have to be careful not to set too aggressive a rake angle, and make sure the bore radius is large enough for back relief.   It’s possible to try to bore too small a hole for a particular bar and orientation.


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## mmcmdl (Jan 19, 2022)

The bar isn't the issue . The stick out is . Think of boring on the lathe . You have a 12" boring bar , you're going to get chatter . You have a 2" bar , you're not . Cut that shank if that's the only holder it will fit .

It's looking like that is sticking out 8 inches on that little BB ?


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## Janderso (Jan 19, 2022)

mmcmdl said:


> The bar isn't the issue . The stick out is . Think of boring on the lathe . You have a 12" boring bar , you're going to get chatter . You have a 2" bar , you're not . Cut that shank if that's the only holder it will fit .


Oh I’m cutting baby!!
Dave, could you show me your boring set up?
If it’s too dang cold out there I understand.
How you feeling.


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## DavidR8 (Jan 19, 2022)

I guess there’s no way to hold it directly in the 30 taper thing right?
I’m thinking that a 30 taper adapter for the boring head is the solution. 
I had a think about my setup and the first time I used it I just stuck the straight shank in the er30 collet. But I remember it chattering. 
Then I pulled out my MT3 collets and chucked it directly in the spindle. 
Presto no more chatter. 


Sent from my iPhone using Tapatalk


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## mmcmdl (Jan 19, 2022)

I'm doing fairly well . Actually , I'm not in that bad of shape for the shape I'm in !   I sold every boring head I've ever owned Jeff . I have my Narex and my Wohlhaupter boring/facing heads left . Just thinning the herd out over the years .


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## Janderso (Jan 19, 2022)

mmcmdl said:


> I'm doing fairly well . Actually , I'm not in that bad of shape for the shape I'm in !   I sold every boring head I've ever owned Jeff . I have my Narex and my Wohlhaupter boring/facing heads left . Just thinning the herd out over the years .


You have a Wohlhaupter? Oh there is some suckage going on here.
They only cost about $3,000-$5,000 last time I looked.
Sweet tools though.


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## mmcmdl (Jan 19, 2022)

Janderso said:


> You have a Wohlhaupter? Oh there is some suckage going on here.
> They only cost about $3,000-$5,000 last time I looked.


I kept my mini Wohlhaupter and the big Narex . I haven't looked at the prices these days but I sure remember what I shelled out for the Narex years back . You never saw the B/F ing heads ?


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## benmychree (Jan 19, 2022)

You should get a boring head with a 30 taper shank and mount directly into the spindle taper; way too much overhang, no wonder it chatters.


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## woodchucker (Jan 19, 2022)

mmcmdl said:


> I'm doing fairly well . Actually , I'm not in that bad of shape for the shape I'm in !   I sold every boring head I've ever owned Jeff . I have my Narex and my Wohlhaupter boring/facing heads left . Just thinning the herd out over the years .


I was not even aware that Narex was into machine tools. They only recently made it to the states for Woodworking chisels and such..  So I wasn't familiar, but looking at their boring head, it looks as nice maybe even better than a Wohlhaupter.


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## mmcmdl (Jan 19, 2022)

woodchucker said:


> I was not even aware that Narex was into machine tools. They only recently made it to the states for Woodworking chisels and such.. So I wasn't familiar, but looking at their boring head, it looks as nice maybe even better than a Wohlhaupter.


They've been around forever , and they ARE very nice heads . Either one will peel a tenth off with no problem . These two heads will be the last tools I'll ever sell . ( I hope )    The two put together for size comparison. 

This is getting fun . I know where my sh** is down the basement and it's easy to find .


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## benmychree (Jan 19, 2022)

I had a big Narex, cost about $2700 as I recall about 30 years ago, I think, I used it on my Universal HBM and the #3 P&W jig borer; I was not too impressed with its ridgidity on the HBM, chattering.  A nice boring/facing head for smaller mills is the Chandler Duplex, very nice, have one now with 30 taper mount; shanks are interchangeable on them.


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## mikey (Jan 19, 2022)

jwmelvin said:


> What’s the best way to do this? I’ve sometimes held a 6” scale on the tool’s top surface, but sometimes by eye.


Lay the flat part of sliding part of the head on a flat surface; I use the anvil on my vise next to the mill. Now eyeball the flat on top of the tool so it is parallel to that flat surface. Your eye can get it straight to within a few tenths this way - good enough, I think.


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## mikey (Jan 19, 2022)

woodchucker said:


> I have no trouble with mine being straight. It cuts perfectly well.





Winegrower said:


> I have never had to grind my import boring bars, you just have to be careful not to set too aggressive a rake angle, and make sure the bore radius is large enough for back relief.   It’s possible to try to bore too small a hole for a particular bar and orientation.



I normally use cobalt HSS tools ground for use in a boring head so the flat on top of the tool is ground to center. However, I have brazed tools that are not and they cut fine. I will grant that the ideal is to have the flat on center but it is more important to align the tool so the tip is aligned properly or your leadscrew readings will be off.


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## Tipton1965 (Jan 19, 2022)

mmcmdl said:


> The bar isn't the issue . The stick out is .


My thought exactly on first glance.  You have a springy diving board there.


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## benmychree (Jan 19, 2022)

mikey said:


> Lay the flat part of sliding part of the head on a flat surface; I use the anvil on my vise next to the mill. Now eyeball the flat on top of the tool so it is parallel to that flat surface. Your eye can get it straight to within a few tenths this way - good enough, I think.


A few tenths of what?


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## mikey (Jan 19, 2022)

benmychree said:


> A few tenths of what?


Of dead parallel when compared to a reference surface.


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## Larry$ (Jan 20, 2022)

Interesting! I just bored some tough steel yesterday. Nice clean shavings, no chatter. Cheap Chinese brazed bars in a cheap Chinese boring head with R8 shank in a 18 year old mill. Bars have round shanks and I use the eyeball method of alignment. Slight positive rake. Bars have been sharpened but original profiles hit or miss maintained. .003" down per rev. combined with a .005 to .008 DOC. I'm turning it relatively slowly @ about 200rpm because it is a fairly unbalanced system. Total seat of the pants machining.  IMHO the problem with chatter at the beginning of this thread  is the diving board setup.


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## benmychree (Jan 20, 2022)

mikey said:


> Of dead parallel when compared to a reference surface.


Measurable by what method?


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## mikey (Jan 20, 2022)

benmychree said:


> Measurable by what method?


Tell you what, John. Just put in whatever word or measurement that makes you happy, okay?


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## Liljoebrshooter (Jan 20, 2022)

Here is my boring head setup Jeff.

Joe


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## Janderso (Jan 20, 2022)

benmychree said:


> You should get a boring head with a 30 taper shank and mount directly into the spindle taper; way too much overhang, no wonder it chatters.


That’s probably the only way to do it. I didn’t know I could do that.
I tried to figure out how this head is mounted on the straight shank, couldn’t figure it out. It must thread on.


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## Janderso (Jan 20, 2022)

Liljoebrshooter said:


> Here is my boring head setup Jeff.
> 
> Joe


That’s a hell of a lot more robust than my ****ty set up.
Found this Criterion head with my taper. $800 on Ebay.


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## Janderso (Jan 20, 2022)

benmychree said:


> You should get a boring head with a 30 taper shank and mount directly into the spindle taper; way too much overhang, no wonder it chatters.


After a quick search, it appears these heads unscrew and i did find a 30 taper that is pretty cheap. Good enough for the Shars boring head.I think I’m making progress here.
Thanks


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## mmcmdl (Jan 20, 2022)

Janderso said:


> I think I’m making progress here.


And that's all that matters !


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## Janderso (Jan 20, 2022)

mmcmdl said:


> And that's all that matters !


In fact,
I just bought a 30 taper from Shars for $42 shipped. Plus, It has the correct draw bar threads, hard to find. They are usually metric.
It came apart really easily.
I guess I could make a metric draw bar. Never threaded metric. You know my Colchester can do it, the question is, can the operator handle it?


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## mmcmdl (Jan 20, 2022)

Janderso said:


> I guess I could make a metric draw bar. Never threaded metric. You know my Colchester can do it, the question is, can the operator handle it?


Of course you can ! You can't mess up a G job , just call it revision 1A or whatever . If you get up to rev 9Z , well , we'll have a heck of a fun thread to follow .


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## macardoso (Jan 20, 2022)

NMTB 30 Shank 1-1/2-18 Threads for Boring Head
					

<!-- <ul><li>Thread Size: 1.5"-18</li><li>Style: 30 NMTB 1/2"-13 Draw Bar</li></ul> -->




					www.shars.com
				




NMTB30 to 1.5-18 boring head adapter. I'm guessing you have an ISO30 spindle but you should look for something like this.

EDIT: I didn't read to the end and whoops, you already got one.


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## benmychree (Jan 20, 2022)

Way too much money for what it is, keep looking, Jeff


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## Janderso (Jan 20, 2022)

macardoso said:


> NMTB 30 Shank 1-1/2-18 Threads for Boring Head
> 
> 
> <!-- <ul><li>Thread Size: 1.5"-18</li><li>Style: 30 NMTB 1/2"-13 Draw Bar</li></ul> -->
> ...


That’s it.


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## Janderso (Jan 20, 2022)

benmychree said:


> Way too much money for what it is, keep looking, Jeff


Seemed pretty reasonable to me. $29 for the part. $15 for Fed X to get it here was the cheapest.
I am on a fixed income now. We’ll see what the boss says when she does the bills. I haven’t spent a dime in three weeks.


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## benmychree (Jan 20, 2022)

Janderso said:


> Seemed pretty reasonable to me. $29 for the part. $15 for Fed X to get it here was the cheapest.
> I am on a fixed income now. We’ll see what the boss says when she does the bills. I haven’t spent a dime in three weeks.


Perhaps I read it wrong, it is a affordable product after all.


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## macardoso (Jan 20, 2022)

I wouldn't grind that for $30  Maybe add an extra 0 to the end.


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## ericc (Jan 20, 2022)

Worth it for covid sanity.  I made my own boring head with a tapered shank.  No interfaces.  It seems to work just fine, but it is used rarely.  I'd rather bore on a faceplate if I can.


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## Janderso (Jan 20, 2022)

ericc said:


> Worth it for covid sanity.  I made my own boring head with a tapered shank.  No interfaces.  It seems to work just fine, but it is used rarely.  I'd rather bore on a faceplate if I can.


You sir are in a different class than me.


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## Larry$ (Jan 21, 2022)

Janderso said:


> the question is, can the operator handle it?


Give it a try. I've certainly made my share of screwups. It's called learning. Last night I set up to turn some 1/2-20tpi on  a longer piece. Center drilled, chucked in a 5C collet, my upside down, hand ground tool in place, made my scratch pass.... *error*. Lathe still set up for the last time I did metric threads. Time to change the change gears.  I'll cheat and just make a few passes with the lathe then finish with a die since this is a long part and will flex. My only 1/2-209 die is a hex (rethreading die), I don't have a round adjustable die that size.


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## Janderso (Jan 25, 2022)

benmychree said:


> You should get a boring head with a 30 taper shank and mount directly into the spindle taper; way too much overhang, no wonder it chatters.


John,
It made all the difference in the world.
I can actually use my mill to bore.
The auto feed is really cool!
I took a video but the file was too big.
I’ll attach a link later.
Thanks for all the help guys! 
Had I taken the time to grind a shorter bar I would have had better success but as it is, it worked well enough.


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## jwmelvin (Jan 25, 2022)

Looks much better. I had the same reaction the first time I used auto down feed on my knee mill.


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## davidpbest (Jan 25, 2022)

Janderso said:


> John,
> It made all the difference in the world.
> I can actually use my mill to bore.
> The auto feed is really cool!
> ...


If you want a Wohlhaupter or Narex type boring/facing head with a 30 taper, you can sometimes find them used on eBay, but it could take a while to find the right size head and 30 taper shank.  I found my complete R8 setup on eBay about a year ago, and I can confirm it’s capable of tenths level precision.  Here is a new Vertex (Taiwan) version that would set you back about US$1,100 from *this supplier* in the UK.


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## Janderso (Jan 25, 2022)

davidpbest said:


> If you want a Wohlhaupter or Narex type boring/facing head with a 30 taper, you can sometimes find them used on eBay, but it could take a while to find the right size head and 30 taper shank.  I found my complete R8 setup on eBay about a year ago, and I can confirm it’s capable of tenths level precision.  Here is a new Vertex (Taiwan) version that would set you back about US$1,100 from *this supplier* in the UK.


For $1,100, that's not a bad price if one really wanted one. The accuracy and it's unique operating capabilities makes it a valuable tool.


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## Janderso (Jan 25, 2022)

jwmelvin said:


> Looks much better. I had the same reaction the first time I used auto down feed on my knee mill.


I think the mechanical operation of the auto down feed could be improved on. It sure has known glitches.
I went through mine a few months ago. Replaced a couple parts and deburred everything. Works slick now.


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## DavidR8 (Jan 25, 2022)

What is this "auto down feed" thing you speak of?


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## MrWhoopee (Jan 25, 2022)

Janderso said:


> I think the mechanical operation of the auto down feed could be improved on. It sure has known glitches.
> I went through mine a few months ago. Replaced a couple parts and deburred everything. Works slick now.


I have to work on mine, it won't stay engaged. I have to hold the lever to keep it from popping out. It just hasn't been enough of a problem yet to motivate me to dig into it.


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## MrWhoopee (Jan 25, 2022)

DavidR8 said:


> What is this "auto down feed" thing you speak of?


Quill feed on BP type mill.


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## DavidR8 (Jan 25, 2022)

MrWhoopee said:


> Quill feed on BP type mill.


I'm completely envious!


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## Janderso (Jan 25, 2022)

MrWhoopee said:


> I have to work on mine, it won't stay engaged. I have to hold the lever to keep it from popping out. It just hasn't been enough of a problem yet to motivate me to dig into it.


The trip linkage may be broken. Very common.

I hope this helps.
I'm sure you know about H&W Repair? They have videos on this subject I believe.
This may help as well >>> = oops, it looks like I came late to the party. Don't you just love how everyone want s to help!!!!




__





						power quill feed doesn't stay engaged?
					

hey guys, got a 1974 BP 2J 1.5hp. mill, it is my understanding the power quill feed should stay engaged until the micrometer nut bottoms out right? my lever springs back immediately which is especially dangerous because the clock spring on opposit side of head is broken/damaged in some way so...



					www.practicalmachinist.com


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## davidpbest (Jan 25, 2022)

That J-head quill power feed is a Rube Goldberg contraption of the first order - right out of the railroad engineering era.  Still, I wouldn’t be without it for boring operations.


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## Janderso (Jan 25, 2022)

So, the problem was the length of my tool. 
Shy smirk


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## Janderso (Jan 25, 2022)

DavidR8 said:


> What is this "auto down feed" thing you speak of?


Oh yeah baby, turn this lever, decide if you want slow, medium or energetic and flip the lever.
You can set a depth stop too.


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## Janderso (Jan 25, 2022)

davidpbest said:


> That J-head quill power feed is a Rube Goldberg contraption of the first order - right out of the railroad engineering era.  Still, I wouldn’t be without it for boring operations.


You said it David.


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## Firstram (Jan 25, 2022)

MrWhoopee said:


> I have to work on mine, it won't stay engaged. I have to hold the lever to keep it from popping out. It just hasn't been enough of a problem yet to motivate me to dig into it.


Slightly loosen the set screw that is in the end of the feed trip lever. It pushes up on the pin that disengages the lever, if it's too high the lever won't stay latched.  Part number 144
Edit: looks like I was late to the party too.


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## Aukai (Jan 26, 2022)

I'll have to go look at that.


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