Sparky_wrench,
I didn't know that electronic handwheels could develop backlash, I thought this would only apply to mechanically linked handwheels. What is physically happening to the electronic switch in the handwheel to develop backlash and require a comp adjustment?
I visited the local Southwestern Industries (SWI) rep yesterday, and was given a demo for the ProtoTRAK SLX Controller box which is used on the SWI 1630SX lathe. It of course went good, though there was one instance where the simulated cutting of a thread ran the cutter into the chuck. He said it was a bug in the simulator model only and wouldn’t occur if the controller had been connected to a physical machine. He also admitted he hadn’t upgraded the software from version 1.0 to the latest version. Hummmm.
The controller is a Black Box and the rep told me that the user is locked out of most of the CNC functions going on in the background, including Windows XP. That doesn’t thrill me either, running a CNC lathe on top of Windows XP, or any version of Windows for that matter. This I see as an important difference, though running a full-blown computer operating system in the background does have its benefits, like support utilities, file converters, spreadsheet program editing, familiar Windows file structure and manipulation, external keyboard, mouse, and others.
Sparky_wrench, what kind of support have you needed from SWI? What problems have you encounter with these machines, any common ones? I will ask about the stepper/servo drives and the max force they can develop and compare that to the HAAS TL-1. Thanks.
Geof, that’s a good suggestion to test the actual material, especially loading the machine down hard. I have an ACRA 1340 TVS,
http://www.acramachinery.com/Manual_...es/1300TVS.htm,
(electronically variable speed) manual lathe with a high (500-3000 rpm) and low (100-500 rpm) gearbox. It seems to have plenty of torque at the low end and I have had no issues there. I really like the ACRA. As for the new machines, neither company has the actual machine on the floor to demonstrate. I have seen the HAAS at a new customer’s shop, and the owner loved it. But I think most anyone who just bought a $30K lathe better love it or repeat “I love it” a few thousand times till they do! Thanks, Geof.
SWI really pushes their computer driven user interface, and the canned routines for user friendliness and versatility. When the SWI rep saw my HAAS Toolroom lathe brochure, he smiled and said let me tell you two things about the HAAS machine (I’m not a Machinist by trade, so bear with me on the terminology, description, and details below):
1) The HAAS digital readout (DRO) gives its location relative to the home location which is at both X and Z max from the chuck, at the tail end of the machine, and displays this somewhat useless value. I asked if the absolute home display value can be reset to wherever the operator sets it, and he said no. I need to verify this with the HAAS rep. I didn’t ask if the DRO had a relative or incremental mode which could be set to any location, and much more useful to the operator.
2) The HAAS user input and canned routines (not straight g-code input from a CAD/CAM program) do not allow the machine to cut both towards the centerline of the part and away, within the same cycle. He says this is because when the tool offsets are programmed at the beginning, only one side of the cutter tip is located and the HAAS controller doesn’t know where the back side of the cutter tip is. An example of this operation would be cutting an OD groove with a 45 degree ramp towards the centerline of the part, a flat, and then a 45 degree ramp away from the centerline of the part. He says the HAAS controller will choke on the 45 degree ramp away from the centerline because the controller doesn’t know where the backside of the cutter tip is. In this example, the front side of the cutter was located. If it had been setup to cut away from the centerline, fine, but then it wouldn’t know how to cut towards the centerline. This operation would require a true g-code routine from a CAD/CAM program, or manual g-code programming. The concept makes sense to me, but I need to confirm this. It would be a serious limitation to manual programming, but it may also be sales hype!
Sorry to write such a long post, but I find this fascinating and I enjoy understanding as much as I can.
Thank you.