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Heidenhain TNC355 opinions wanted

Kempsmith2

Plastic
Joined
Jun 22, 2011
Location
Saskatoon, Canada
I'm considering installing a TNC355 on my late 80's FP4NC. It came with a broken down very early Dynapath that I really don't want to get involved with. My question is just how well the TNC355 would perform today with CAM software. I don't intend on doing any great amount of surfacing so if it's a bit slow that's not a big deal, but I would want to be able to reliably drip feed large files. Any opinions on the idea of installing this particular old controller? How is it to operate for general work? This will be a retirement hobby machine so I don't want to spend too much, but I also don't want to go the LinuxCNC type route. After 30 years of using a Dialog 11 I want an industrial hardened control that I know is going to work without bizarre bugs, as I no longer have the patience to be constantly piddling around to keep a PC functioning.
 
I use a TNC355 on my 1991 Hermle UWF851 multiple times a week to cut complex 3D surfaces. It's not the fastest but I drip feed all of the code over an RS232 connection with TNCServer software (free download from Heidenhain). Works flawlessly. I use HSMWorks and implement all of the tool paths I used with a brand new 2013 vintage Haas without any issue. As far as how it works, it's hands down my favorite CNC control I've used. Straightforward and rock solid.

You'll want to change parameter 60 (speed pre-control) to 1 (off) as that drastically improves the speed of the machine when running adaptive and surfacing toolpaths.

Since you are upgrading the control is there any reason you wouldn't go with a slightly newer TNC control that can handle higher transfer data rates. I don't have any knowledge of these newer TNC controls but would think something released in the mid-late 90's would have faster transfer speeds and probably wouldn't cost much more than a 355 but I could be wrong.

Interested in your decision process, keep us posted!
 
I use a TNC355 on my 1991 Hermle UWF851 multiple times a week to cut complex 3D surfaces. It's not the fastest but I drip feed all of the code over an RS232 connection with TNCServer software (free download from Heidenhain). Works flawlessly. I use HSMWorks and implement all of the tool paths I used with a brand new 2013 vintage Haas without any issue. As far as how it works, it's hands down my favorite CNC control I've used. Straightforward and rock solid.

You'll want to change parameter 60 (speed pre-control) to 1 (off) as that drastically improves the speed of the machine when running adaptive and surfacing toolpaths.

Since you are upgrading the control is there any reason you wouldn't go with a slightly newer TNC control that can handle higher transfer data rates. I don't have any knowledge of these newer TNC controls but would think something released in the mid-late 90's would have faster transfer speeds and probably wouldn't cost much more than a 355 but I could be wrong.

Interested in your decision process, keep us posted!

Thanks so much BugRobotics, that's exactly the sort of insider information I was hoping for. The 355 is sounding like exactly the controller I want.

There's a number of reasons I'm leaning towards the TNC 355. A big one is it appears the most straight forward with the least number of unnecessary extras, yet still decently capable of serious work. I want a control I can install, troubleshoot myself and repair without costing a fortune. When I go into retirement I suspect money will be getting tight so I can't have something rare or too up-to-date that'll be costly to fix. The 355 appears to have been fairly popular as there are plenty available on the market right now, still commanding reasonable prices, rather than being sold off as scrap. Heidenhain has a pile of free documentation available for it, including a very thorough Technical Manual for installation and setup/commissioning. It was an optional control for the Deckel at the time so it must have been well compatible.

The TNC 355 appears to come out in 1987. The next step up which I also have my eye on is the TNC 360 from around '93 or '94. It's still the same keyboard but getting more powerful. The TNC 370 appears to have come out just a bit later and it's very similar but with a faster processor yet, and a new style QWERTY keyboard. Browsing the manuals, these two controls are getting more complications piled on able to cause grief, so that's putting me off slightly, but on the other hand, as you suggest it probably wouldn't cost much more. But we'll see, still early in my search. Any other suggestions are welcome.
 
BugRobotics pretty much covered everything from the user point of view

Regarding a DIY retrofit, how are going to approach the PLC programming? I'm asking because from reading the manual I gathered that machine builders that used this control back then worked together with Heidenhain, meaning, they composed the PLC program on the control for that particular machine, then this program gets sent to Heidenhain who then compile it and burn a chip that you then install in the control and run.
You might of course run your custom PLC program from memory, but it wouldn't be the most reliable way of doing it.

Another idea would be to chose the donor machine so that it is about as similar to your Deckel as possible, and rewire the Deckel the same way the donor machine was set up, but might not be as easy as it sounds.

From troubleshooting the TNC355 on my Mikron, I can tell you that while the manuals were very useful, they are far from complete, and I had a distinct feeling they were written to be used as a learning aid in a class, not as a complete instruction on how to set it up or troubleshoot.
I had issues with the IO board on my TNC, and it was quite straight forward to diagnose, but I don't think it would be as easy to troubleshoot something on the logic board...

While I think TNC355 might be a better fit for you than the LinuxCNC, the latter one might be easier to implement and work just as well, and if something on the pc-control side does fail, it wouldn't be too difficult to replace in 5 years or more
 
Very good points jz79. I'll be the first to admit when it comes to PLC programming I haven't a clue! I have no experience whatsoever, I'd be diving into the dark in that area. I've been studying the Technical Manual for the TNC 360 and apparently it is entirely possible for the user to create/edit the PLC program, and then compile to the internal EPROM, entirely from the TNC's keyboard. I read it as being pretty straight forward (famous last words). There are some 128 pages in the PLC programming chapter but still a person has to have a clue what they're doing, and I'd be starting from zero. As you say, if the donor machine was similar enough to the Deckel I should be able to edit the existing PLC program. I'm sure I'd be fumbling in the dark but I'm confident a person could do it. It's actually adding a bit of an interesting challenge to this retrofit idea.

I'm leaning towards the TNC 360 at this point. It's very similar to the 355 with even the PLC program being transferable. No great reason other than being a slightly later model so there must be some refinements. The 360 uses all the same readily available components as the 355 and the logic unit itself is also readily available.

Dan
 
I'd probably get a line of communication going with the Heidenhain crew in Germany that still use and repair these specific controls. Every time I've contacted Heidenhain or Hermle, most recently about a non-stock axis drive replacement, they always send my inquiries to Germany.
 
Those controls have got to be 25 years old or more.

I would consider something newer unless they are free

I have done modification of PLC programs on a heidenhain, not rocket science

Newer ones have a built in logic analyzer
 
It's a good point gustafson and I'll agree it does seem foolish to retrofit with such an old control. I've been looking at the TNC 4xx series and they are tempting, at least getting up to the later 90's. Decisions Decisions.....

I happened to look at the Wikipedia page for Heidenhain and apparently they'd built nearly 200,000 CNC controls by the end of 2006. Holy cow, no wonder there are so many used ones on the market.

Dan
 
The 410 has flatscreen and pretty large memory
426 is pretty sophisticated and I think uses a hard drive

I don't know what your budget is

I paid I think 8 grand for a TNC 310 20+ years ago new.
Whole control was the size of the flatscreen

analog drives were 350 a piece, VFD...
 
This is a budget program ,yes?
Wonder why you are not upgrading the current control that is already fitted and presumably worked at one time.....
Dynapath is an industrial control, can drip feed and is capable of some surfacing right from the control...they are conversational
Dynapath controls can be upgraded i believe..
Might have a look at :
DynaPath

Might be worth a call.
Cheers Ross
 
Yes actually Ross I used the same logic when I got the machine; the Dynapath ran the machine for many years so I'll just keep it and upgrade the best I can. But, before I got the machine someone had been at the controls, as if using it for parts, I don't know, but after getting it I found a couple of the connectors interfacing with the machine had been cut out. As it is now the wiring is untraceable. I could probably figure it out if I had the Dynapath pinouts and access to the PLC program but why waste the time with such a control. It's a very early generation unit so to upgrade at all basically means replacing the whole thing. On top of that the console is a god awful looking thing. I did make a light attempt to contact Dynapath a couple times for upgrade information by email but got no response, so I took that as a sign that I'd be better off dumping the whole works in the bin and start over.

My work mill will be getting retrofitted to a TNC 640 once the Covid situation improves so I'll be getting very familiar with Heidenhain programing, making a TNC the obvious choice for my home shop. The 640 is laid out on my bench at work as we're building a console for it now. It's a beautiful looking control, but so far I haven't been able to find the "Launch" button for the space shuttle.

I wouldn't say it's a low budget operation, but I'd rather not spend much on it simply because I don't expect to be using it that much, and when I do it'll probably be quite basic stuff. A lot of manual operation probably and at most recreating broken/worn parts like vintage engine castings or similar type surfacing. A 4th axis for gear cutting mainly. After a working life of machining I don't intend on spending my retirement running machinery the whole time, and I most definitely won't be doing paying jobs from other people. So this is the reasoning for leaning towards a basic control like the 355/360. One I can walk up to after several months of inactivity and immediately have it doing what I want with no hassles.

Dan
 








 
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