Thread: opinons on a used machine...

Hi all,
After many many delays I'm finally about ready to purchase a "hobby" mill. Its got all the features I'm looking for, and I think its reasonably priced at 13K(well the upper end of 'reasonable' at least). But before I jump in I thought I would check it out here to see if I'm way off base (on price, and quality of hardware/software).

Machine has less than 400 hrs, 30 taper,3 second power drawbar, some tooling included, heidenhain TNC 310 Control, with rs232 port,Baldor variable frequency motor control, 1 phase or 3 phase, 3 hp motor.Automatic way lube.
I'm in northern california and the machine is near my shop.

Any comments are welcomed.

Well, I am certainly no authority on equipment for hobby use, and don't have much experience on anything less than a full machining center. Having said that, take my opinion with a grain of salt. If I were looking for a machine for the use you describe, I would think that looks like a fine deal. Not really a steal, but not really a rip off either.

My bet is Don will have the most experience with proper pricing of equipment.

Looks like a good buy to me. Very unusual to see a Heidehain control on a Tawainese machine, but this is a good thing, as the 310 is still a current model and an excellent control. That control panel alone (i.e. no drives, motors..just the control panel) sells for $9,000 new.

I have a slightly older version of that machine with a dead Centroid control. About to start a PC retrofit.

Answer a few questions and I will give my opinion. What year is the control? How many
programmable spindle speeds, are they reversable,
and what is the knee travel?

We've been looking for something similar for our work model shop. This is at the low end on pricing.

Nice - pity it's not in Colorado or I'd send the boss over.

Chris P

what is the knee travel

Zero

9"x42" table, 30" X travel, 12" Y travel, 16" Z travel

I'll have more details about the age of the control and such on monday.

I haven't seen the machine first hand yet, but I have some experience with a sharp knee mill and it seemed very rigid, the whole head of this machine moves vertically for the Z travel, and it looks to me that it would be more rigid than having the knee move.

I say "hobby" because I am not a super hardcore CNC machinist that is going to require maximum productivity from this machine. I am a relative novice, and I will be using the machine to learn on and to fufill modest requirements for my small engineering and fabrication shop. I understand that many would reccomend a VMC, and maybe one day I will be able to upgrade.

Anyone have any gripes about hte reliability or useablitiy of the heidenhain controll? at 9k for a new interface, I'd hate to hear they had lousy customer service and were habitually faulty.

I really do appriciate all of the feedback! Keep it coming.

Well to answer Dualkit first;
What year is the control? ~1999-2000
How many programmable spindle speeds? variable 0-4000
are they reversable?yes
and what is the knee travel? no knee its a bed mill.

To answer Stampyoldani;
I wouldn't call this a hobby machine at all. The TNC 310 is a super reliable control only problem I have ever seen is a little LCD burn in from a customer that left the control on 24/7 for years.
As far as useability the only limiting factor, I feel, is block processing time for 3D contour milling (I.E thousands of lines of .001 movement).
Heidenhain service and support of the control is good.
Also that machine uses linear scales on all 3 axes making it much more accurate and repeatable since its a true closed loop.

The same thing new appears to be about $22,000
in some of the catalogs I have looked in, I would
try to get it for 1/2 of that $11,000 for starters. If you don't want all the bells and
whistles. Mid 80's 3 hp Laguns, 3 axis, without
the programmable spindle, with the same table
travel, can be had for $3500-$4500.

As soon as you get it make a backup of all the parameters.
I know for a fact that if you use the com port on the
TNC310 control you can send in bad code
in a porgram that can and will crash the control.
Teh reason i say this is I have some problems with my post file for Gibbs
and some times the program sent into the machine
will crash the controls eprom
Now I am back to reloading the control parameters

ooh that is a bit scary, I am planing on using Mastercam to generate much of my code (from solidworks files). I was hoping that for some parts I would be able to drip feed programs directly from the computer into the running machine.

Fredj: I would suspect there is something besides a bad code, I have had problems similar with my 310 with ground loops or a bad power supply.

Back up the parameters, also the plc

the 310 is not as beefy as other heidenhains, but still better than most

Two thoughts.
I have had some experience with "Sharp". Parts where pricey and not readily available. The few parts I did get required modifications to work properly. Not being a hobbyist, I can't wait a few weeks till someone gets around to shipping a part that "should" work.

At 13K I would pass due to the lack of Rigid Z travel and Auto-Tool Changer. I would also pass at 1/2 that price for the same reason.

However, if machine fits your needs it doesn't appear abused and its clean.

Fredj- Which software version are you running? I've never had the problems of parameters get erased, unless the battery is dead and the machine sits for a while. Also of course you should have hard copy backups of you PLC and MP list. But both of these can also be stored permantently onto the Eprom.

I gave it a first look today, The machine was clean, and looked ot be in good shape, but it hadn't been used much in the last 2 years. It has some sort of baldor variable freq. drive unit. It looks to be a very good feature, and useful for my shop as it will adapt the freq to run off of the 220 single phase that I have. But it makes a whiny noise at low rpm. The spindle sounds good, with just a quiet whirr at high rpm. The tool changer was quick and a nice feature, the vertical travel is assisted by that air cylinder thats on the side of the machine for really smooth travel. It has a place for a 4th axis board in the controls. and It has fully programmable spindle speeds and coolant,although the coolant plumbing was missing.

Overall the machine looked good, I was a bit dissaponted that the only inputs appear to be either manual programming, or by the rs232.

I borrowed the programming manual and am going to learn a bit about the control so I can prepare myself to check the machine more thoroghly later this week.

It seems like the consensus is that it not a horrible machine, but could get expensive to service. which makes me a little nervous although the machine really appears to be in excellent condition.

At this point my major holdup is that I need to figure out the controls.

Keep it coming, I appriciate the feedback.

The machine can hold about 6000 blocks of program, so drip feeding may not be required[?], as long as you don't try to hold too many in the machine

Heidenhain service is the best in the business. They swapped my control via UPS red label when my 24v supply fried it,I had it in the next day and running. They billed me when the repaired my unit, cost ~1200 bucks IIRC.