Leveling an hardinge hlv-h lathe
For now I will try 4 thou steel shim under the bed and start headstock alignment work. I guess the high spot in the bed plate was cancelled out by the low spot in the base casting.Ī total of 2.5 thou is now removed from the original bedplate thickness, so another regrind could be done if required if I could find a quality facility. High spot testing with the camelback high spot test also looked as good as I can measure. My indicator test now looked very good (no measured error) except at the extream tailstock end. I took it home and reattached the bed plate to the base. The top grinding results were a big improvement, but now there was a high spot of about. I decided to try surface grinding of the top at a local machine shop (30 minutes away). I also found that the base casting was low in the middle -based on a high spot test using an old camelback straight edge. The grinding machine had simply followed the worn surface! The grinder had actually only removed 0.0002 from each end and 0.002 from the middle low area.
![leveling an hardinge hlv-h lathe leveling an hardinge hlv-h lathe](http://www.lathes.co.uk/hardinge/img5.jpg)
The top grinding was not parrallel as expected. The largest error was exactly where the before grind error was (near front of headstock).įinally I took the bed plate off the base and did micrometer measurements along both edges of the bed plate.
![leveling an hardinge hlv-h lathe leveling an hardinge hlv-h lathe](https://www.machmarket.com/images/39478/392x378x90/5097369f7e1b5.jpg)
This tool gave the same error as using the tailstock as a sliding base. I constructed a better sliding indicator tool that had three point contact on top and two point contact with the dovetail. Now it varied by 1.5 thou -I was NOT happy. Before the regrind the indicator varied by almost 3 thou over the length of the bed. Once home I did some indicator measurements by using the tailstock as a sliding base and contacting the underside dovetail. It looked great when I loaded it up and drove home. Only 0.002" were removed (according to his measuring) from the top and about the same from the sides. He ground the top first and patiently let things cool between passes (2 days total). His grinder was old but looked well maintained and I think called blanchard. There is only about 2 places that will do this work that I could find -and they were a 7 hour drive away! The one I picked insisted on bringing the bedway and base together so that any warpage due to it's 33 year previous life would not be a factor. I had my bedway reground here in Ontario. I need to have this done to my lathe and I haven't researched the cost yet, but as with all things Hardinge it will be expensive! Since this is such a critical thing to get right I'm going to go with an experinced Haridnge shop on the bed regrindĭon, Thanks for that information.
![leveling an hardinge hlv-h lathe leveling an hardinge hlv-h lathe](http://www.babinmachine.com/images/hlvrebuild/hlv8.jpg)
Over the years I've read a few horror stories about grinding shops ruining the bed plate to high temperature damage and other ways they were damaged. Since the carriage follows that angled edge, if that gets out of wack then you'll have problems. It is also critical that the angled sides of the bed plate are parallel to each other and the center line of the lathe. If there are existing shims under the bed plate then you know it's been reground at least once, and you'll need to factor that in. You will need to keep track of how much material you take off and add the same amout in shim stock under the bed He's a friendly guy who has freely shared information with me, and I know to a lot of other Hardinge lathe owners as well - you might want to give him a call.
![leveling an hardinge hlv-h lathe leveling an hardinge hlv-h lathe](http://www.lathes.co.uk/hardinge/img4.jpg)
I've learned a few things about that topic from talking to Paul at Babin Machine. Jim - I forgot to mention some things about the bed grind question you asked.