[ger21]

If anyone here doesn't like what others have to say, please ignore them. Name calling and posts that do nothing but argue will be deleted.
Don't turn this into a Tormach thread.

[mactec54]

handlewanker

There is nothing wrong with what you want to do, with having a mechanical lever, for the draw bar activation, there is nothing new to do it this way, there are machines that still use a lever system, just having an air cylinder is easier to do the job

In the photo being shown, with the air cylinder he has on the mill, there has been no design put into that part at all, that is an air over oil setup, is way bigger than it needs to be, this has been a off the shelf item, just mounted on top of the head

You could do the same with around 3" tall cylinder, may be less, most machining centers have a multi stack/stage air cylinder, as in the photo, this can be really small when designed for the job it has to do, a photo of a multi stage air cylinder

[handlewanker]

Hi.....I expect you're quite right, but I am against having the air solution and prefer to go all electric......less plumbing, less leaking etc etc.

Louie, you're somewhat right too.......in addition to the ER32 collets I also invested in a set of ER20 for the HS spindle.

It is quite on the cards during a milling set up that you'd need more of one type of collet if the cutters, drills etc are within the same crush down size of the collet, meaning you need to keep buying extras of the same size etc......I prefer to add to the ER32 stuff as and when...... I've got a couple of sets already.

If I'd plumped for the ER20 chucks for the milling spindle I'd be limited to the max size you can get into that collet range which is 13mm max.

I fully imagine that a long series 20mm cutter would be more stable when you're shaving the side of a large piece of work, or down in a pocket etc, than the same length in 13mm.....my choice.

My mistake....'tis push not pull to release.

Now the draw bar has been sorted out, it only needs Defeng to submit his design for approval.

BTW.....one thing no one has commented on or realised and that is with an air solution (or electric too) the cylinder doing the pushing is attached to the frame of the mill head, or even the spindle body.

When the cylinder pushes it is applying the load directly to the draw bar end and also the spindle bearings when it pushes down on the draw bar......by nature of the fact that the spindle is a rotating body and the push mechanism is fixed......it cannot be any other way in that design.

In the design I have the push is only on the draw bar and is isolated from the bearings.....try working that one out.
Ian.

[mcphill]

...cylinder pushes it is applying the load directly to the draw bar end and also the spindle bearings when it pushes down on the draw bar...it cannot be any other way in that design...

You are 100% wrong. I will let you figure out why.

[mactec54]

Now the draw bar has been sorted out, it only needs Defeng to submit his design for approval.

The blind leading the blind

When the cylinder pushes it is applying the load directly to the draw bar end and also the spindle bearings when it pushes down on the draw bar......by nature of the fact that the spindle is a rotating body and the push mechanism is fixed......it cannot be any other way in that design.

Not correct, it all depends on how it has been designed, as to where & how the load/force is applied, if designed correctly there is zero load on the Bearings with the use of an air/oil or electric for activation of the draw bar

In the design I have the push is only on the draw bar and is isolated from the bearings.....try working that one out.

Very easy, no working out to do, thousands of machines already are doing it like this, but if you are using your lever design everyone would like to see what you have come up with

[ihavenofish]

When the cylinder pushes it is applying the load directly to the draw bar end and also the spindle bearings when it pushes down on the draw bar......by nature of the fact that the spindle is a rotating body and the push mechanism is fixed......it cannot be any other way in that design.

well no. some do certainly, usually low end basic machines, but they use bearings designed to handle the load of releasing the drawbar. most industrial machines, and even tormach's drawbar for example, dont put any load on the bearings when the tool is released. its a nice easy system.

In the design I have the push is only on the draw bar and is isolated from the bearings.....try working that one out.
Ian.

its been worked out - 100 years ago. the question has always been why you are reworking it in your mind?

[G59]

Right on.

[integymachine]

Does this machine also require an air supply to blast the taper during tool change? Or possibly for positive air pressure inside the bearings to keep debris out.
I would be positive that a manual change or a lever actuated draw bar like an Emco pcmill doesnt require air because the operator can wipe the tapers.

Sent from my LGLS740 using Xparent BlueTapatalk 2

[ihavenofish]

there is no air path through the spindle on the iso20 model. so no air cleaning of the taper.

its perfectly valid not to want to use air, but he seems to be kicking the idea down as if its a bad one, when its the standard on many of the best machines money can buy.

[handlewanker]

In the ideal World......where have I heard that before.........because thousands of things all follow the same path doesn't necessarily mean it's the ideal one.......sometimes it's the best one, but that's not ideal.

Ideal, interpreted as the best that CAN ever be, as opposed to the next best that could be.

BTW.......if you apply a force to an object you also apply a corresponding reverse force.....unless you are jet propelled and create the force without needing a place to apply the force from.

The power draw bar DOES apply a reverse force to the machine's frame, casting whatever it's attached to.......not a problem, but the main force is applied to the top of the draw bar AND THAT APPLIES FORCE DIRECTLY TO THE BEARINGS PER SE via the spindle, .....in case you missed that out......how can it not be so.......enlighten me if otherwise please.

True, the spindle design calls for heavier bearings that cater for the extra loading when the power is applied......not an ideal solution, but the best that is around, considering.

I don't think Defeng would take kindly to being classed by Mactec59 as blind in the design field........this whole thread is about his design(s), and on that score I placed my money firmly on the nail.

I'm going for the electric power draw bar design as it's an instant fix despite it also being in the class as not the ideal solution but the best that can be.

I invent and design things for solutions to apparent problems......that is my interest and to date has paid me quite a few thousands dollars (20K +) for inventions that really worked and were adopted by industry for their use when the existing methods failed......long story.......so I speak from a background of achievement, not wishful thinking, and if Thomas Eddison was alive he'd no doubt say...."That's my boy".....LOL.

The apparent problem I've previously stated is that the Bellville spring washers are in a relaxed state when they are most needed to apply the maximum clamping force and at their most compressed state when they are being forced to release the tool from the draw bar gripper.....not the ideal state of affairs, but the best that is currently available.

Without hijacking the thread with infinite nit picking question answering, I'll just state that I have a design that applies the reverse to the currently well used designs and does not load the bearings at all, but as the electric design is an apparent instant quick fix, that's what I'll be using.

I don't know if Defeng is also working on an alternative pneumatic PDB for the SVM-0, as some others seem to prefer it......that's his prerogative.
Ian.

[handlewanker]

well no. some do certainly, usually low end basic machines, but they use bearings designed to handle the load of releasing the drawbar. most industrial machines, and even tormach's drawbar for example, dont put any load on the bearings when the tool is released. its a nice easy system.







its been worked out - 100 years ago. the question has always been why you are reworking it in your mind?

Oh?....... I wasn't aware the CNC industry was around 100 years ago., or PDB's either.

Perhaps you could back it up with some info as to how it worked.....no sense in me re-inventing the wheel.....talk is cheap, tangible results count more.

BTW, it's not only in my mind but in my computer data base too.
Ian.

[Dingenman]

Pff... Ignore mode should stay ON but someone here makes it very hard to resist to comment.

All I want to say is: do some research (the information is available) before placing incorrect statements about technical challenges which have been dealt with a long time ago.

Sorry to have intervened your monologue..

[rustyh]

BTW.......if you apply a force to an object you also apply a corresponding reverse force.....unless you are jet propelled and create the force without needing a place to apply the force from.

So a jet engine doesnt have a corresponding reverse force!! I'd love for you to explain this one!!

I invent and design things for solutions to apparent problems......that is my interest and to date has paid me quite a few thousands dollars (20K +) for inventions that really worked and were adopted by industry for their use when the existing methods failed......long story.......so I speak from a background of achievement, not wishful thinking, and if Thomas Eddison was alive he'd no doubt say...."That's my boy".....LOL.

Egotistic as usual, I would imagine Thomas Edison would put you right on pretty much everyone one of your thought processes

I would suggest .......respectfully of course.....that if time to unclamp tools is so important, perhaps ya'all need to invest in a course for advanced Gcode programming which would be better to maximise the cycle time instead of quacking about a few seconds pushing a button for QCT with an electric solution.

Under Mach3 control and with ATC in the picture, the electric power draw bar is controlled by the program, so the cycle time is hardly affected anyway.....wise up, ya' blinkers are on too tight.......LOL.

Only a few days ago, you were delving in to your first G-Code tutorial Videos, now you know all this too, thats some quick learning, going to have to call you jonny 5

[rustyh]

Rustyh..........learn how to spell or get your spell checker fixed....its Defeng, not Defneg...........rotflmao....

I invent and design things for solutions to apparent problems......that is my interest and to date has paid me quite a few thousands dollars (20K +) for inventions that really worked and were adopted by industry for their use when the existing methods failed......long story.......so I speak from a background of achievement, not wishful thinking, and if Thomas Eddison was alive he'd no doubt say...."That's my boy".....LOL.

I know you're quite sensitive when it comes to spelling, so just thought I had better point out that Edison is spelt with one "d".
Right I'd better "rotflmao" you must be using the same spell checker as me!

[mactec54]

I don't think Defeng would take kindly to being classed by Mactec54 as blind in the design field........this whole thread is about his design(s), and on that score I placed my money firmly on the nail.

You are missing the boat, Defeng has not done any Design what's so ever with the setup of the air/oil cylinder, this setup that he is showing is an off the shelf item just mounted on top of the head above the spindle, with the way this has been mounted it will place a direct load on the Bearings when activated, which is wrong, so no thought/design has gone into this part at all

So if he was waiting for approval then my answer was correct

[louieatienza]

.....unless you are jet propelled and create the force without needing a place to apply the force from.

Ian.

I'm sure Sir Isaac Newton and Antoine Lavosier would tend to disagree (Newton's 3rd law of motion, conservation of mass)

[louieatienza]

You are missing the boat, Defeng has not done any Design what's so ever with the setup of the air/oil cylinder, this setup that he is showing is an off the shelf item just mounted on top of the head above the spindle, with the way this has been mounted it will place a direct load on the Bearings when activated, which is wrong, so no thought/design has gone into this part at all

So if he was waiting for approval then my answer was correct

Are there advantages of using air over oil on a system such as R8 QTC where more force is needed to depress the draw bar?

[mactec54]

Are there advantages of using air over oil on a system such as R8 QTC where more force is needed to depress the draw bar?

Yes it can be a lot better than just an air cylinder, you can generate a lot more force, & have a very small unit, smoother movement than with just an air cylinder, air cylinder stages can be less also, just think of it like the brakes on you car, you have a small master cylinder piston, pushing the fluid to a large diameter piston, depending on the ratio of the ( 2 ) piston will determine the force you get, it can easily be thousands of lbs output from a 100 PSI air supply & still be a very small unit, there is a lot that you can find on the internet on this subject

A small machine like this though, with a need of only 800lbs, a multi stage air cylinder is all that is needed this can be very small around 3" tall or less

[ihavenofish]

Oh?....... I wasn't aware the CNC industry was around 100 years ago., or PDB's either.

Perhaps you could back it up with some info as to how it worked.....no sense in me re-inventing the wheel.....talk is cheap, tangible results count more.

BTW, it's not only in my mind but in my computer data base too.
Ian.

the iso standard tool holder, the one used in your iso20 spindle was developed in 1911. power drawbars followed shortly after.

cnc machines as we know them today have been around since the 1950's.

nothing here is new. at all. not a single feature either mechanically, electrically, or even on the computer side. the only thing new on a machine like the svm-0 is the low cost and speed of the computer.

watch the tormach videos on the drawbar and youll see how they manage to release the tool with an air cylinder while putting no force on the bearings. the iso20 spindle defeng is supplying is capable of this, though his current drawbar release system seems to not use it.

pressure on the bearings is NOT necessarily bad though, IF the spindle is designed to handle the load. most steel bearing low speed spindles like the iso20 are perfectly capable of taking the small drawbar release force. a ceramic bearing, or one balanced for high speed, i would not want any force on it.

[jips]

Yes it can be a lot better than just an air cylinder, you can generate a lot more force, & have a very small unit, smoother movement than with just an air cylinder, air cylinder stages can be less also, just think of it like the brakes on you car, you have a small master cylinder piston, pushing the fluid to a large diameter piston, depending on the ratio of the ( 2 ) piston will determine the force you get, it can easily be thousands of lbs output from a 100 PSI air supply & still be a very small unit, there is a lot that you can find on the internet on this subject

A small machine like this though, with a need of only 800lbs, a multi stage air cylinder is all that is needed this can be very small around 3" tall or less

And what about the life time comparison between this two different systems air vs oil ? Maintenance etc...