endmill

[IanN]

Can't just help but put in my Two Cents Worth here as we are also in "the ***** Class" as so crassly painted by the Maestro !!
We have joined this most knowledgable Forum not to create any Models or the like but just so's we can LEARN from some of the good Guys here who'd share their Brilliance, Expertise and Experience in Machining and Technical Works.
Regrettably, all this has taken a different meaning to some Folks here.
All we can do now is stand by the roadside and shake our heads ashamedly.
Sad indeed.
aRM

Hi aRM,

Sorry for the delay in responding to your comments, I only check forums once or twice a week.

As I said to Tom, you are quite right to pull me up for my frustrated reference to "idiots". As I stated, I teach engineering apprentices (I don't know your background, but if you are a qualified machinist or engineer, remember "trade school"?). Over a five year period we try to drum in certain knowledge but there are a couple of areas where we know, deep down, we are probably wasting our time. "Blowing down" a machine is one of these areas. For one day a week we can talk about it, show the evidence, all agree it is a foolish practice, but on the other four days the students are at their place of work and see older, more experienced machinists doing what we have told them they should never do.

A few students may remember and follow good practice for the rest of their lives, but most will fall in to bad habits. They cannot justify what they do, but they do it anyway.

I'm sure you will have been in discussions with people who clearly know they are wrong but refuse to accept it. The situation is easy to recognise - When they cannot show that your points are factually incorrect, and when they cannot provide any evidence to support their view, they will often resort to one (or both) of two tactics:

1) Change the arguement in to something they CAN win - avoid answering questions, talk about other topics - politicians do it all the time

2) Say "But eveybody does it" - Taking pens and paper home from your place of work? The occasional use of recreational chemicals? "Don't worry! Everybody does it". Well no they don't and it doesn't make it right or sensible.

When you see those tactics in use, you know you have "won" the arguement and there is no point in further discussion because the other side will simply not accept reality

Maybe some people will view the video I posted and think "I've been blowing down my lathe for years, when you sit and think about it, perhaps it is not such a good idea. Maybe that is why I had to replace the headstock bearings. Perhaps I should dismantle the lathe saddle/apron and just check the feed gears...." and others will carry on without questioning their believes "Well I've done it for years, everybody does it, that video is just fake news..."

I appologise again if my inappropriate use of the word "*****" offended. Like you, I am a member of a nunmber of forums in order to learn - I've been in engineering for over 50 years, I'm past retirment age, but I still learn new things and pick up bright ideas from forums such as this, and I'm still working because engineering is fun. I spend all day doing what I love to do, and at the end of the month, they pay me!

All the best,
Ian

 

[SmithDoor]

He says he is making a gear pump so that will imply two overlapping holes so intent would be to plunge with the milling cutter. The unusual size requirement is so there is very little clearance between gear and the wall of the pocket.

That sounds steel or cast iron if that is case then HSS cutter would work.
It also sounds like this new pump some adjustment you could use a standard cutter.
or use a tool post grinder on a HHS cutter and grind to size.

Dave

 

[Jasonb]

I think on the Demon V8 it is set into the end of the engine block which is aluminium.

Yes I did suggest skimming a thou or two off the crests of the gears so a fractional imperial cutter would give a close fit, though I would not bee keen to plunge on an item like this as the bottom of the hole won't be truely flat so the pump wont work quite as well with small gaps.

 

[Badhippie]

God I wished I had the luxury of having CNC or have somebody repair the equipment I use that would be great. I would like to touch on the cleaning of mill or lathes. You might be correct to some extent about blowing metal in places it don’t belong. But don’t you think that brushing off the equipment also puts metal in the nook and cranny’s of the equipment???
Same way as using coolant will wash debris into places it don’t belong. And using air to cool cutting tools.
If your wipers and way covers are in good shape this should stop most of the debris.

Also this is happening as you use the machine debris are working there way under and in between and over places that cause wear. Something that has not been mentioned and apparently is not in the training or schooling in some parts of the world. Is the safety hazard that blowing equipment off poses. Yes blowing off the equipment is a safety hazard.

Is using air the best thing to do?? No it’s probably not. But it is more common then most people know. People that work in a production shop don’t have much time in between set ups and jobs. So air is becoming used more because it’s faster to use. Don’t get me wrong that don’t make it right. But I think that’s some of the problems today.
BTW have you looked at keyway end mills they are slightly undersized and are square cut.
They are what I use most of the time to cut keyways in shafts

 

[chrsbrbnk]

You are supposed to clean the change gears once in a while, and a little oil might help. Tubal cain's video just shows an incomplete job of cleaning and lubrication. professional shops pretty much all have air compressors ,wonder why? The plunged end mill approach of hole sizing and making just has varying amounts of accuracy in size and location only experience is going to tell you when and what is appropriate. A shop I worked in ground down the od of a lot of end mills just for hole sizing

 

[SmithDoor]

They make 11/32" end mill that is .34375"
That is only .002 off size odds are after milling it will be very close.

Dave

Hullo members, any information where I can purchase a .346" 4 flute carbide endmill? have searched the net no result. rrocky

 

[IanN]

God I wished I had the luxury of having CNC or have somebody repair the equipment I use that would be great. I would like to touch on the cleaning of mill or lathes. You might be correct to some extent about blowing metal in places it don’t belong. But don’t you think that brushing off the equipment also puts metal in the nook and cranny’s of the equipment???
Same way as using coolant will wash debris into places it don’t belong. And using air to cool cutting tools.
If your wipers and way covers are in good shape this should stop most of the debris.

Also this is happening as you use the machine debris are working there way under and in between and over places that cause wear. Something that has not been mentioned and apparently is not in the training or schooling in some parts of the world. Is the safety hazard that blowing equipment off poses. Yes blowing off the equipment is a safety hazard.

Is using air the best thing to do?? No it’s probably not. But it is more common then most people know. People that work in a production shop don’t have much time in between set ups and jobs. So air is becoming used more because it’s faster to use. Don’t get me wrong that don’t make it right. But I think that’s some of the problems today.
BTW have you looked at keyway end mills they are slightly undersized and are square cut.
They are what I use most of the time to cut keyways in shafts

Hi Mr Hippy,

I think we are in total agreement with each other:

Swarf will always go places you don’t want it

Cleaning with a brush or shop vac is not perfect

“Blowing down” a machine is not a good idea and will introduce more problems and make the existing ones worse

I agree on every point

You mention “wipers” - as an aside I’ve noticed many people do not wash and clean the felt pads that are used as wipers. In our college shops, these are washed and dried once every 6-8 weeks as the machines are in almost constant use. If you have a home shop you may only work in there once a week, and use your machine occasionally, so the wet felt wipers may be resting on the bed ways for a couple of weeks. If you use soluble cutting fluid I would wash and dry the wipers at the end of session

All the best
Iann

 

[IanN]

You are supposed to clean the change gears once in a while, and a little oil might help. Tubal cain's video just shows an incomplete job of cleaning and lubrication. professional shops pretty much all have air compressors ,wonder why? The plunged end mill approach of hole sizing and making just has varying amounts of accuracy in size and location only experience is going to tell you when and what is appropriate. A shop I worked in ground down the od of a lot of end mills just for hole sizing

Hi Chrsbrbnk,

Do you believe the debris shown in the video is the result of natural wear of the gears?

We have a differing opinion on the problem shown. You favour ignoring the cause and curing the symptoms to hide the true issue. I prefer to solve the source of the problem

I am aware of the reasons why industrial shops have air supplies. In our college shops we have piped air - without it we could not operate pneumatic chucks or the numerous air-tools in common use. Do you seriously believe it is provided to “blow down” machines?

All the best,
Ian

 

[Badhippie]

Our wipers here in the states are mostly made of rubber. Or have been replaced with rubber.
There are some older units that still have felt
Thanks
Tom

 

[Jasonb]

Seems Haas cater for both schools of thought.

 

[chrsbrbnk]

It's pretty obvious the crap on the gears is blown in from the air hose , its also pretty obvious no one has looked in there cleaned them up and lubricated them.
In the industrial shops I 've worked in , visited, and several I've seen on the internet virtually all the machine/work stations had air nozzles , most with quick connects to address other operations. The primary exception was around the grinders that were cleaned with vacuum cleaners or brushes. Several of the newer enclosed cnc machines have both a coolant hand spray nozzle and an hand held air nozzle. Application of all them require some amount intelligence while using. I suppose one could take a poll and figure out the reality of use.