It is funny how we adopt “common” wisdom so often without research. We trust those around us who are doing similar things to give us good advice and most of the time they do. Recently I ran into what could have been a very expensive problem because I trusted similar things advice. A Haas tech rep told me that if I don’t run the mill on parts that once a week I should at least run a program that will keep ball screws lubricated. I ran this program the other day and walked off. The next day I go and look and laying on the Y axis way cover was my Cat40 holder and now broken end mill. Here is the culprit responsible.
no name retention knob
Shops around here have told me that they save money on retention knobs and typically look for cheap prices or used but in seemingly good condition knobs from places like EBay. They also never torque these things in but just crank on them until tight. Now I know every person by that metric has a different torque value. Since my arms are pretty big I crank them down.
The end result of something like this can ruin your spindle at worst with damage to the inside of it from a loose Cat40 holder clanging around. This is a very expensive repair and will eat up both your time and money. I talked to Technology Sales in Chattanooga TN which has supplied me for years and we got off onto a whole world of things I had no idea of. None of the people around here who have machine shops do either as far as I know.
JM and no name retention knobs
Now I happened to have some used JM knobs in use and I will talk about what I observed with them shortly. For now though look at the difference in the construction of the no name and the JM knobs. Now go here and read https://rktorquetest.wordpress.com/pdf-downloads/ . These articles are six and seven years old but the information is current and in searching I could not find anything that supersedes what they talk about with a newer better design. The tooling guy at Technology says there is nothing better and the customers he has that try them migrate solely to the JM knobs rather quickly. These ran me $28.00 each and it is just one of those funny things we machine shop owners do at times. We balk at high prices in some areas because we just don’t know there is an underlying reason to spend the dough anyway.
Judging by the studies done and the specified torque value for the Haas style knobs of 22.5 to 25 foot pounds I was probably only three to four times what I should have been. I have no doubt the no name knob was also not good from the very start but I exacerbated the whole situation with the gorilla torque method. JM also sells a knob socket which you can use to correctly install knobs. In all the shops I have been in I have never seen or been told about this.
JM retention knob torque socket
I switched to Schunk hydraulic holders for my HSM Adaptive cutting because you get perfect concentricity on your end mill center line which gives better life and cut quality. I did not realize however that typical retention knobs would introduce measurable distortion of the tapered shank on the Cat40 holders as one of the articles in the web link demonstrates. I could prove to my own satisfaction they were telling the truth by looking at my holders which had been in service for some time.
The ones with the used JM knobs even though no doubt over torqued showed an even contact pattern on the tapered shank. The ones with the no name wonders showed a ring of contact at the top and bottom but very little in between. I can see with my own eyes what they were talking about. I and can also easily believe because of this that there were induced inaccuracies from distortion of the tapered shanks as the study said.
I think it would be time well spent for any milling machine owner to investigate what practice your shop uses and make changes before it comes back to bite you like it almost did to me. Save your spindle and improve your surface finishes and accuracies in one easy step.
Posted in Uncategorized
Tagged CAMWorks for Solid Edge, CAMWorks for SolidWorks, Delcam, EdgeCam, Esprit, Haas, hsmworks, Inventor Pro HSM 2016, Mastercam, Powermill, Retention knob, Surfcam, vertical maching centers
It was a couple of years ago when I gave up on Solid Edge ever getting the market share it deserved. One of the chief reasons was what I perceived to be a new ploy by Autodesk to assemble pieces of the complete manufacturing puzzle together to smother competition. This first really began with the acquisition of HSMWorks and continued with the purchase of Delcam lock stock and barrel. Today I was perusing the CNC Cookbook site and specifically this area. http://www.cnccookbook.com/CCCNCSurveys.html
Reading the CAD and CAM surveys was a bit of an eye opener. Now there is a section in here where they talk about how they generate the data used if you are interested. I was not as I figured with a couple of million visitors a year the surveys probably had a pretty good representation of what is reality in shops earning a living with software.
As a CAD side note here go through the years and see how poorly Solid Edge fares here. This has been my personal experience also for years as I have heard “you use Solid Edge? you are the first person I have met to do so” so many times it makes me ill. This is true by the way 60 some miles north of the SE headquarters in Huntsville. It fully explains why there are fewer than 500 users at the annual convention which ought to draw many more with its bargain rate pricing. The users just are not out there to begin with and CNC’s surveys are the first independent effort at generating market share data I have found that appears valid based on my own experience. It is what happens to a fine product whose future is determined by people who would just rather it went away.
Of even greater interest to me were the CAM surveys done here in 2010,2012,2014 and 2015. Go there and read in full these various years for CAD and CAM but in a nut shell here is what they had to say about CAM market share.
HSMWorks all Inventor and SW 1% 17%
Camworks I assume SW and SE 2% 5%
NX 6% 5%
Powermill 2% 5%
Featurecam 5% 3%
Mastercam 29% 27%
Basically Autodesk has gone from nothing to 25% of the higher end CAM per CNC Cookbook criteria.
In the “low-cost” category per CNC cookbook data we have Fusion 360 going from 0% in 2012 to 55% share in 2015.
I have been fascinated with the well planned multi-year conquest of Mid Range Manufacturing started by Carl Bass a few years ago and this survey was the first time I could see quantifiable results coming in. It does not look good for the competition. It is not my intent to hammer on the subscription thing here but with these stellar numbers I wonder why common sense has not overtaken the agenda at Autodesk. It is time to rethink this and stay with the seats and subs and let users choose. You guys are whipping the market as it is far better than I had imagined so don’t get greedy and keep winning customers just the way you have been by earning it with superior products and prices. Clearly it has been successful to date and market share is accelerating.
The other amazing thing here is the stark contrast to Dassault. SW has been famous for vaporware and grand visions from the bizarre mind of some French guy who could care less about reality. For years they have trotted out one cloud based thing after another just to watch them crash and burn. Autodesk on the other hand has Fusion 360 and the only thing that has crashed here is Dassault’s abortive plans to be first and foremost with the cloud for manufacturing.
I just sit here and think about SE as I write all this. Here longer than Inventor with 8% current market and here as long as SW with 22.7% bringing up the rear with 1%. It really makes a difference when the guy in charge has a plan. There was a brief period of hope under Newbury Cooper but they were run off for the cardinal sins of competency and caring about the future. Things not valued at Siemens who is struggling financially and can’t figure out why. SW’s share by the way has declined from 25% in 2013 and that is the result of mismanagement also. SW has had to work really hard to run off their long-suffering and amazingly loyal customers but they have begun succeeding.
Here is my vote for Autodesk to not change things as they were at the end of 2015 and continue on the way they were with a proven method for conquest.
Posted in Uncategorized
Tagged Autodesk, camworks, CAMWorks for Solid Edge, Dassault, Featurecam, Fusion 360, Inventor HSM Pro, Mastercam, Powermill, Siemens, Solid Edge, Solid Works, Solidedge, solidworks