[segengineering]

Hi all,
Dose anyone know an easy way to threadmill a taper thread, (NPT).
I have V24 BodCad-Cam.
As an example I need to produce a range of NPT Threads, (3/4"NPT 1" deep to 1.1/2"NPT 1.25" deep), I'm looking at using a Insert type Threadmill, the insert as 5 pitches, (or teeth).
An easy method that could be applied to any taper thread would be most helpful.
I'm confident that there are some really smart BobCad user here that can solve this problem, or better still if someone from BobCad could produce a helpful tutorial video, showing a simple way to do this.
Thanks, and over to you helpful BobCad users

[jrmach]

I know you can draw your geometry and do it with a single pitch thread mill.A bit involved for sure.Think same maybe could be used with 5 pitch????????????The drawing would have to reflect the tool path.More involved for sure.
Thought BoB was going to include Taper threads in an update in V25??????????
So NO,no easy way I know of,,,However I have heard there were g-code calculators out there for this.Might try Google for a Free one.

[Big Chips]

damn...kinda gonna need this in the future...wait i need it now!!! Jr...aint it about time for a update or version???

[jrmach]

Yeah,I hope they do 1 more update,,there is somethings still there to be done.I am not holding my breath though,it does seem like all softwares leave somethings before the next version(V26) comes out.And it seems like it probably is getting close to time.I hope I am wrong.

[TonyW]

I was told they are in fact working on taper threads for future update (V25), but I don't know when that will be. For now since I use Carmex threadmills, I use their online calculator and post processor at CARMEX. Does a great job. If you are not using Carmex I'm sure the company whose tools you have should have something also available. Creates the G Code, then I just copy and paste into program with Predator.

[bobcad guy]

I haven't done npt with bob, but if I did, I would simply tell it im doing a straight thread, and set dia of tool to largest part of thrdmill, id do a rough pass, where I lie and tell bob the thrdmill dia is a lil bigger, then a second pass to finish it, with the proper number for the tool dia. I know this is a work around, but it seems like it would be easy, just a little time consuming. there is of course, the ever old reliable handwritten option. its as easy as g1 g91 g41 x to half of hole dia d1, g3 x0 y0 z amount of pitch,then I or j - half of dia. its quite simple.

[Big Chips]

dang software should have it already....PERIOD!

if I have to go and send in a support ticket...I am going to just send in the link to the CNC Zone Bobcad forums...lol

[gsRAP]

I've used a free program from Advent. It allows you to create custom tools, so you can use tools from other manufacturers.

[jrmach]

I haven't done npt with bob, but if I did, I would simply tell it im doing a straight thread, and set dia of tool to largest part of thrdmill, id do a rough pass, where I lie and tell bob the thrdmill dia is a lil bigger, then a second pass to finish it, with the proper number for the tool dia. I know this is a work around, but it seems like it would be easy, just a little time consuming. there is of course, the ever old reliable handwritten option. its as easy as g1 g91 g41 x to half of hole dia d1, g3 x0 y0 z amount of pitch,then I or j - half of dia. its quite simple.

That will not work.You have to draw your tool path in 3D wire frame and draw your lead in and outs.It's a bit involved for sure.A search on this Forum will reveal quite an in depth discussion of this and options.In one post I outline it in detail.A work-around for sure,but doable.All and all,I think using a g-code calculator from the manufacture of your tool would be the best option to explore.Seems Tony did just that.


Here is one thread of many that come up in a search http://www.cnczone.com/forums/bobcad...d_milling.html

[TonyW]

I haven't done npt with bob, but if I did, I would simply tell it im doing a straight thread, and set dia of tool to largest part of thrdmill, id do a rough pass, where I lie and tell bob the thrdmill dia is a lil bigger, then a second pass to finish it, with the proper number for the tool dia. I know this is a work around, but it seems like it would be easy, just a little time consuming. there is of course, the ever old reliable handwritten option. its as easy as g1 g91 g41 x to half of hole dia d1, g3 x0 y0 z amount of pitch,then I or j - half of dia. its quite simple.

as JR said, can't do that way. If you do a straight hole the gage lines of taper won't be correct. Tool has to follow a tapered helix. Even though NPT threadmills are tapered, as you are moving up out of the hole the diameter of toolpath must keep getting larger.

[segengineering]

Hi everyone,
Well thanks to everyone for there imput, I did also follow the link for the other threadmilling post, (interesting read).

It looks like BobCad need to pull there fingers out and do something about all the threadmilling routines they have, to improve them and make them simple to use for both single point tools and multi pitched tooling. Also taper threads, are a much need inclusion to the routines, after all they are a basic engineering standard that have been around for a few hundred years now.

I don't want to sound like i'm rubbishing BobCad about this as in genral the product is good, but its little things like this missing feature, loss of DONGLES for Bobcad, and the fact that they always seem to release versions of their software full of bugs that then need regular updates to put right, (they should get a group of users to fully product test future versions for 12 months before the release to the rest of us).
These are some of the reasons I have not upgraded to V25 yet, and may never do so.

SO COME ON BOBCAD DESIGNERS, FIX THIS ISSUE, AND MAKE IT AVAILABLE TO OLDER VERSIONS TOO. Threading is after all a basic Engineering Function.

Thanks again to everyone who as helped or comented on this thread