Tabletop CNC

[toolsrul]

Hi Ollimatti, the most direct and costeffective way to get a TAIG out here in Europe was for me to get a good friend to take one along from California. The thing is so small it fits in hand-luggage and the cost is so low that in The Netherlands no import duties are required.

Don’t know if you are aware of a spin off from Taig called Micro Proto (microproto.com). They have some pretty good deals besides having some slightly advanced machines for sale as well. Easy to deal with and should be able to help you with international shipping. Good luck.
Regards,
George

 

[NapierDeltic]

I see 4th axis and electronic lead screw suggestions.
How to program all this is a mystery to me. (not willing to spend the "big bucks" ). How to do the camCAM for the 4th axis is a big bottle neck.

I understand your question and do not intend to run from a problem i have raised to myself.
With only leadscrew in native form. using milling spindle/mill as tool, you can make it sequentially, manually driven. Make a table - angle vs radius for the cam, advance chuck 1 degree at a time and input the y manually (and x in the loop with constant parameters). but for the constant radius portion of the cam, things go much faster.
Another way -if you do not have a leadscrew with GRBL-like features- is to build a Grbl controller (dirt cheap), add a driver and stepper for lathe spindle and go full CNC lathe (temporary setup). CAD-CAM knowledge required.

 

[mrehmus]

Don’t know if you are aware of a spin off from Taig called Micro Proto (microproto.com). They have some pretty good deals besides having some slightly advanced machines for sale as well. Easy to deal with and should be able to help you with international shipping. Good luck.
Regards,
George

Microproto supplied my TAIG mill to Robert Washburn. Not a bad setup although, when I got the system, I rebuilt the Z-axis holding system to insure it would not move.

 

[awake]

He no longer has this for sale

Clough42 has made and sells an ELS. Here are some relevant links. Note that I have not tried this out, and have no affiliation and no personal experience with this - only what I've seen on YouTube.

https://www.youtube.com/@Clough42/playlists
https://clough42.com/shop/
https://github.com/clough42/electronic-leadscrew

 

[Alan Merry]

The Clough42 els requires a lot of building and is only single axis. There are 2 others, Rocketronics and els h4 https://kachurovskiy.com/. I actually have an ELS h4 in New condition available for sale if interested. The Rocketronics is the one I am installing in place of the H40.

 

[timo_gross]

The original goal was to create eccentric and not round features (aka cam), possibly many of the cam on one piece (cam shaft).
I still do not understand what the electronic lead screw can help to solve this task, just asking.

 

[NapierDeltic]

The original goal was to create eccentric and not round features (aka cam), possibly many of the cam on one piece (cam shaft).
I still do not understand what the electronic lead screw can help to solve this task, just asking.

Hi Timo,
It is not a round but is a revolution feature so makes sense to be made on the lathe. I have explained above how I see it done with NanoEls 4. You only have to consider it semi-automatic and keep excel tables instead of CAD designing (and I personally don't know yet how to CAD-CAM to the finished product). Much more, Els4 keeps tracking of lathe spindle zeroing so you can step from one cam to the next in a controlled way - for entire camshaft.
Els4 cannot make cams natively because his developer didn't think of this feature yet; but the firmware is on Github and with a pull request -or programming skills- I think it can be done. Either directly or through PC support- it has a wi-fi interface (this is out of my current knowledge ???)
As for CNC lathe, the additional equipment and control is the same as for CNC-ing a mill; only axes definition fits to purpose.

 

[Jasonb]

To do it on a lathe will require two axis as the tool will need to move in and out as the part rotates, a single ELS won't work. The main advantage of the CNC is that you should not get the relativly large faccets that making multiple indexed cuts create. Another problem with doing the indexed cuts on a multi lobe cam on a lathe is that the ELS will move the cutter along the axis and could hit the next cam, you really need the cutter moving across the axis of the camshaft

Even if you have two axis then the cutting speed is likely to be very slow as the rotation of the part will be governed by how quickly the cross slide can move in and out so finish may be a bit rough.

Would work better on a lathe with live tooling as that could run at the correct cutting speed while work slowly rotated but then you may as well use the mills spindle as the "live tool" and do it on a mill.

 

[timo_gross]

Hi Timo,
It is not a round but is a revolution feature so makes sense to be made on the lathe. I have explained above how I see it done with NanoEls 4. You only have to consider it semi-automatic and keep excel tables instead of CAD designing (and I personally don't know yet how to CAD-CAM to the finished product). Much more, Els4 keeps tracking of lathe spindle zeroing so you can step from one cam to the next in a controlled way - for entire camshaft.
Els4 cannot make cams natively because his developer didn't think of this feature yet; but the firmware is on Github and with a pull request -or programming skills- I think it can be done. Either directly or through PC support- it has a wi-fi interface (this is out of my current knowledge ???)
As for CNC lathe, the additional equipment and control is the same as for CNC-ing a mill; only axes definition fits to purpose.

I did not question if it makes sense to use a CNC lathe The concept is advertised in every CNC lathe commercial. Just to make the point I add the random pick! (two to threehundredthousandusdollars and you can buy a machine) Some additional budget for software, training andor technical support and you are good to go.

4th axis CAM (computer aided design) packages seem to be (my opinion; for hobby use) unreasonable expensive (100USD a month and up!).

To do it on a lathe will require two axis as the tool will need to move in and out as the part rotates, a single ELS won't work. The main advantage of the CNC is that you should not get the relativly large faccets that making multiple indexed cuts create. Another problem with doing the indexed cuts on a multi lobe cam on a lathe is that the ELS will move the cutter along the axis and could hit the next cam, you really need the cutter moving across the axis of the camshaft

Even if you have two axis then the cutting speed is likely to be very slow as the rotation of the part will be governed by how quickly the cross slide can move in and out so finish may be a bit rough.

Would work better on a lathe with live tooling as that could run at the correct cutting speed while work slowly rotated but then you may as well use the mills spindle as the "live tool" and do it on a mill.

Yes, exactly. The mass of the cross slide dictates the motor size for the x-axis. A light machine will "start jumping" around I guess. Other enemies are, backlash, and positioning repeatability, and to get working G-code. (easy! just load "CNC_MEM/USER/PATH1" 3:40 haha. )

Greetings Timo

 

[NapierDeltic]

I did not question if it makes sense to use a CNC lathe The concept is advertised in every CNC lathe commercial. Just to make the point I add the random pick! (two to threehundredthousandusdollars and you can buy a machine) Some additional budget for software, training andor technical support and you are good to go.

4th axis CAM (computer aided design) packages seem to be (my opinion; for hobby use) unreasonable expensive (100USD a month and up!).

Yes, exactly. The mass of the cross slide dictates the motor size for the x-axis. A light machine will "start jumping" around I guess. Other enemies are, backlash, and positioning repeatability, and to get working G-code. (easy! just load "CNC_MEM/USER/PATH1" 3:40 haha. )

Greetings Timo

I do not take it as confrontation -at least if it is not about ideas . I don't fight anybody (and don't pretend others do...).
The main ideea is machine's rigid construction is one of main factors of success and the most expensive one. Using existing lathe would solve this roadblock.
In my post I have mentioned the NanoEls 4 (two axis control) should be combined with a secondary spindle in tool-post (6 mm mill as tool ?). In this case backlash has no meaning as you always machine from right to left. You can watch several thread cutting videos with Els4/Els2, performed in loop mode, adjusting the x advance manually. In my case, as relative machining speed is provided by secondary spindle, lathe spindle only works as indexing device. Standard lead-screws with noticeable backlash don't need replacement.
Various methods should be approached for people with various skills. For instance, thinking of Timo's questions , I have imagined another way to machine cams, much more suited to old school lathe machinists.
Profile copying arrangements are usual on lathe. Usually, fixed patterns are used, but nobody said you cannot use revolving ones. An independent axis, geared with lathe spindle 1:1 (toothed belt, pulleys, belt tensioner maybe...) with a dummy cam -3D printed , I think is a reasonable setup. Tool should be a standard lathe tool and machining faster and at correct geometry, without post-corrections other than finishing.

 

[awake]

Perhaps a quibble, but ...

The Clough42 els requires a lot of building and is only single axis.

To do it on a lathe will require two axis as the tool will need to move in and out as the part rotates, a single ELS won't work.

I think of "lead screw" as only referring to the Z (left-to-right or right-to-left) movement, so "more than one electronic lead screw" doesn't really make sense.

Certainly to do a cam on a lathe, we are moving beyond ELS and into CNC territory!

 

[Jasonb]

In my post I have mentioned the NanoEls 4 (two axis control) should be combined with a secondary spindle in tool-post (6 mm mill as tool ?). In this case backlash has no meaning as you always machine from right to left. You can watch several thread cutting videos with Els4/Els2, performed in loop mode, adjusting the x advance manually. In my case, as relative machining speed is provided by secondary spindle, lathe spindle only works as indexing device. Standard lead-screws with noticeable backlash don't need replacement.

Although your method may only make the cuts with the main leadscrew going from right to left the cross slide needs to be fed in and out so backlash will need to be considered.

6mm tool may also have issues. 1, as the lobe of the cam rotates the indexed cut will not always be on the horizontal ctr line it will rise and fall as the lobe rotates. 2. if the cams have less than 6mm space between them then there will be a risk of the right to left cut running into an adjacent cam

If you are using a toolpost spindle and moving tool in/out manually all the single axis ELS is doing is acting as a glorified power feed/reverse

But if you want to post a video of you cutting a multi cam shaft with ELS I'm happy to be proven wrong.

 

[NapierDeltic]

Although your method may only make the cuts with the main leadscrew going from right to left the cross slide needs to be fed in and out so backlash will need to be considered.

6mm tool may also have issues. 1, as the lobe of the cam rotates the indexed cut will not always be on the horizontal ctr line it will rise and fall as the lobe rotates. 2. if the cams have less than 6mm space between them then there will be a risk of the right to left cut running into an adjacent cam

If you are using a toolpost spindle and moving tool in/out manually all the single axis ELS is doing is acting as a glorified power feed/reverse

But if you want to post a video of you cutting a multi cam shaft with ELS I'm happy to be proven wrong.

NanoEls4 is in fact 2 axis so it is definitely more than an Electronic lead screw. I guess he called it ELS just because it was a development of previous version NanoEls2 which was driving only lathe's lead screw. But if you have a lathe spindle precise encoder, always want more.... You can program on y (front -to-back) canned cycles to automatically progress thread cutting, cycles that include tool retraction, so (in our case) if you mill the cam 1 degree at a time, backlash is compensated inside the cycle also on y.
Though, your comment about tool interfering with cam's geometry - it remains valid so has to be judged.

P.S. I have not finished yet my NanoELS and was not my intention to prove anything; just to add my 2 cents to the thread. But if I finish it, I might make a dummy trial. It is clear now that the tool has to have a small diameter. Maybe tip shape and maybe planing spindle rotation. Is a matter of strategy (or tactics???).