Parting and grooving questions

[Anonymous]

I am new to HSM Works and have a few questions on parting and grooving operations. We run a Mori Seiki NL2500Y lathe with live tooling. We have been using Mori APL to program with and it does work pretty good. Our company wants to switch to HSM Works seeing they are going that direction for the CNC milling machines.

Their biggest reason for switching is so that we can work with Solid Works models. The idea that when our designers change the model the changes will update in the Cam. Also, the Cam programmer can work with the model and not have to make his own toolpaths from scratch. Sounds good on the surface but digging deeper It’s not that easy.

We will have to use spun profiles for about 99% of our work and as I found out the spun profiles are not updated when the model is updated. Also, we have to massage the model on most parts. Most of our parts have geometry that needs to have .007 to .010 grind stock added to some diameters while other diameters are to size on the same model.

Here are a couple of things I am wondering about. In Mori APL parting operation, we would part the part to a safe break off point, say .200 diameters then break the part off which leaves a .200 nub on the stock in the chuck. We would then rapid the parting tool to about .220 and then use the parting tool to part off the .200 nub. This works great for us.

Question 1.

My understanding after reading some forum topics is that the parting tool retracts a federate rather than a rapid move if you have a 3” diameter part this adds a lot of time to the machining. Also, unless I am missing something which is very possible seeing HSM is new to me. If we use the parting tool to part off the nub then it starts at the stock diameter rather than the .200 nub diameter and then feed rates back to the stock diameter. Would we have to add a .200 nub to the model to get the parting tool to start at the nub diameter rather than the stock diameter or is there a better way?

Question 2.

Almost all of our parts have a radius on the back side of the part. We do not use chamfers seeing they produce two Sharpe edges rather than one. With a radius there is no Sharpe edge. We use our grooving tool for this rather than the parting tool because it is more ridged. Our models already have the radius on the back of the part. Is there a way to have the groove tool put a radius on the back side of a part without adding a groove in the model?

Thanks,

Steve

[Rob_Lockwood]

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@Anonymous wrote:

I am new to HSM Works and have a few questions on parting and grooving operations. We run a Mori Seiki NL2500Y lathe with live tooling. We have been using Mori APL to program with and it does work pretty good. Our company wants to switch to HSM Works seeing they are going that direction for the CNC milling machines.

Their biggest reason for switching is so that we can work with Solid Works models. The idea that when our designers change the model the changes will update in the Cam. Also, the Cam programmer can work with the model and not have to make his own toolpaths from scratch. Sounds good on the surface but digging deeper It’s not that easy.

We will have to use spun profiles for about 99% of our work and as I found out the spun profiles are not updated when the model is updated. Also, we have to massage the model on most parts. Most of our parts have geometry that needs to have .007 to .010 grind stock added to some diameters while other diameters are to size on the same model.

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Is this for in-house work? I.e., does your company control the source model? If yes, it probably makes sense to have whoever is releasing the CAD release a 'spun profile' model and a 'finished part' model, as you're right. The spun-profile as implemented in HSMWorks is not parametric and ultimately causes massive workflow issues. Honestly, same deal with the grind stock version; control that on the CAD side, rather than cheating it in an uncontrolled manner.

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@Anonymous wrote:

Question 1.

My understanding after reading some forum topics is that the parting tool retracts a federate rather than a rapid move if you have a 3” diameter part this adds a lot of time to the machining. Also, unless I am missing something which is very possible seeing HSM is new to me. If we use the parting tool to part off the nub then it starts at the stock diameter rather than the .200 nub diameter and then feed rates back to the stock diameter. Would we have to add a .200 nub to the model to get the parting tool to start at the nub diameter rather than the stock diameter or is there a better way?

Thanks,

Steve

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The parting operation will feed from wherever the 'retract height' is defined as to wherever the 'bottom height' is defined, and then feed back out to the 'retract height'. The 'lead-in' and 'lead-out' feedrates are not used in the cycle. I still have no idea how this behavior has continued for so long. I can only assume that it's some long-running joke by the development team, as it's really the only reasonable explanation. @al.whatmough to confirm.

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@Anonymous wrote:

Question 2.

Almost all of our parts have a radius on the back side of the part. We do not use chamfers seeing they produce two Sharpe edges rather than one. With a radius there is no Sharpe edge. We use our grooving tool for this rather than the parting tool because it is more ridged. Our models already have the radius on the back of the part. Is there a way to have the groove tool put a radius on the back side of a part without adding a groove in the model?

Thanks,

Steve

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If the model has the radius in place, you can simply run a profile grooving operation with your parting tool to turn the radius. Unfortunately, there's no radius or chamfering option built into the part-off operation, but with the workflow you described, it probably works better this way anyhow.

I've attached a sample part with some quick operations that show some of this, particularly the profile-grooving operation being used to radius and perform most of the part-off, then the part-off being used to part off the remaining .200" nub, with what I believe is the best-case time wise available in HSMWorks currently.

[Anonymous]

Thanks Rob,

Your timely response and helpful answers is greatly appreciated. Attached is a part that I was playing with trying to figure out how to do the slots on the part. I don’t think I have the slotting right but I used the grooving /parting like in your example to see if I could get the same results as you. The one thing I get is a federate from the top of my part rather than the 1.2 diameter I set it to. Your example is what I would like to see. We are using HSM 2016 and your example is in 2017. Could this be why I can’t get the results you did or am I missing something? Again, thanks for your help.

Steve

[Rob_Lockwood]

I'm assuming you stated that backwards, as I'm using 2016 and your file comes up as a future version, so i'm not sure I can be of much help at the moment.

I did toss your part into Fusion, and if it's indicative of an average part for you, i'd say HSMWorks is probably a decent candidate for success.

The milled/non-round features of this part are fairly easy to suppress using Delete Face, which would be a much better solution than using a spun profile.

[Lonnie.Cady]

For that part I would not use a spun profile or delete face, you can easily define the x axis at an angle that produces a complete cross section.  

HSMWorks has too many holes in it at this point.  Even if the part is inductive of your typical work, who knows what lathe work may come up.

Having special configurations for a lathe features and grind stock etc.... is an necessary hindrance in today's cam market.  

Using sketchs in HSMWorks with model override can help especially with the lack of tangential extensions.  Still a pain to use.  Last time I checked in Fusion the sketch still had to be closed to use it for model override and there for not a friendly to use.

The part off issues is probably had is 2nd birthday by now.

I think I have asked for extension for 3-4 years.  Would not count on these features anytime soon especially in HSMWorks.

[Anonymous]

Hi Lonnie, Rob,

Thanks for your input. I really appreciate your help. The part I posted is actually one of the simpler parts. I am new to HSM Works and know next to nothing about it. I thought I would work on the simpler stuff and work up as I get familiar with HSM. My first impressions of it are mixed. There are some nice bells and whistle’s but from what I have read and experienced it seems underdeveloped and buggy. It seems like a lot of the issues people are having is corrected at the post level and work around rather than in the software.

Yesterday we installed the trial version 2017 mainly because of the ability to set the tools live or static. This feature alone is very important to us. Hopefully many other things will be addresses as well. Thanks again for all the help.

Steve