It's time to purchase another 5-axis machine, and Hurco has caught our eye because of it's attractive price. Has anyone worked or owned a Hurco, and if so, could you give me some feedback? Is it accurate? Is it reliable? etc.

Thanks in advance,

Dan

Dan,
I currently work in a small shop we have 1 older Hurco BMC25 which we bought from a company I use to work for that has a few Hurcos. My overall opinion is that it is a reliable machine that that seems well built. As far as being accurate I have not had any issues although I don't have to hold anything more than a .002". We are looking at buying a new machine soon so I have had the Haas, Okumo, Hurco, & a Makino rep in & in my opinion for the money it is hard to beat. Yes, there are better machines out there but the Hurco can handle about anything you can throw at it.

Steved.

Hi Steve,

Thanks for the input. My main concern about the Hurco 5-axis machine is the lack of glass scales. Without scales to feedback the position of the trunion and rotary table you are relying on the encoders, which will deteriorate in time. So although the machine may be accurate now, will it be so in 5 years?

Dan

Dan, I Work For Hurco In The Northeast. Have Installed Two Of The Five Axis Machines. They Are Accurrate. It's Very Hard To Install Glass Scales On The Rotary Axes. The Linear Axes Are No Problem. We Very Rarely Have Customers Use Them. Hurco Uses What Is Called Lead Screw Mapping In Their Controls. Each Axis Is Laser Mapped Every Inch Of Travel Out And Back. The Control Looks At This Mapping As It Produces Motion. Interpolating Between Mapped Points To Keep Accurracy. This Mapping Can Be Redone At Any Time As Needed. Most Customers Have It Redone When They Need Some Kind Of Major Service Likes Ball Screw Bearings Or The Like. Usually I Find Machines That Are 8-10 Years Old And Have Never Been Remapped. I Have A Few Customers Who Want Laser Mapping Done On A Regular Basis (anually/bianually), Usually To Satisfy Iso 9001 Or Qs 9000 Requirements. Ron Meyer

Nice website.

Thanks for the input Ron. I cannot debate the difficulty in adding glass scales to the rotary axis as I am not a machine designer or builder. However, I do know that it is possible, as our Hermle C800U has glass scales on the trunnion and the rotary table.

I will look into "lead screw mapping" a little deeper.

Thanks again for the input,

Dan

"Lead screw mapping" is pretty common in astronomy, where they call it "periodic error correction" to map out varaitions in the worm drive.

Actually, this is something that amatuers should look into to compensate for cheaper screws.

-Jeff

"Lead screw mapping" is pretty common in astronomy, where they call it "periodic error correction" to map out varaitions in the worm drive.
Actually, this is something that amatuers should look into to compensate for cheaper screws.
-Jeff

any bright ideas on how to do the reference measurement DIY / cheaply ?

I think the pro's use laser interferometers ? It probably needs to be dual wavelenght or heterodyne or something to distinguish between the direction of motions.

also, once you have your fancy laser interferometer, how do you mount it so that it is absolutely collinear with the axis of motion ?

Actually, infrared mice might be an option. I think some of them are good to .0005. You could measure both axis, and angular offset, at the same time.

Dan -Should I move this to a new thread?

-Jeff

How about using a rotary encoder on the screw and a linear encoder running parallel to the screw fastened to the nut somehow? Feed the encoder outputs to different axii on a DRO readout and compare the readouts (DRO head or CNC software). Record the differences and positions of differences.

Even if the linear encoder was not as long as the screw you could reposition it along the screw to map the screw in sections.

This would not be as accurate as laser interferometry, but it should be fairly accurate with use of accurate encoders.

What do you think?

Alan