Electronic lead screw ELS - Rocketronics solution on Modern Tool C0636 lathe

[Janger]

@Rocketronics Thanks for posting your explanation of metric/imperial and your conversion story. Metric / imperial is one of those topics that makes the members ornery. We don't talk about politics, religion, operating systems and perhaps we need to also need to ban talk about imperial/metric. Kidding guys - just kidding. The members are great bunch of generous people but some things bring out the torches and pitch forks.

I wish we could convince our American friends to switch to metric so we could just give up on imperial completely. @Dabbler mentioned a bunch of things holding us back. Here in Canada materials, tooling, machines, metrology are all imperial. I'll add two more - fasteners in metric are in poor supply and selection. The second additional reason is perhaps more subtle. Imperial is the convention and everyone's experience using imperial for feed rates and DOC, threads etc. and our professional machine shops also usually operate in imperial or so I am informed. Some people are determined and committed to use metric - and they get to convert all their material sizes to strange metric measurements and deal with the pain in that manner instead. How thick is this aluminium plate? It's 1/4" so 6.35mm. You can't buy aluminium plate in 5mm or 6mm thickness - I don't even know how it is sized in metric. Need 10mm rod for something? You can buy 3/8" or 9.525mm or perhaps 7/16" which is 11.11mm. You see it's just maddening.

I have a suggestion on the user interface for imperial mode on the Rocketronics control. Instead of displaying just one of 0.21875" or 7/32" could you display both? Fractions are such a pain.

 

[TorontoBuilder]

Instead of displaying just one of 0.21875" or 7/32" could you display both? Fractions are such a pain.

+1

I got to see the rocketronics system first hand today. As soon as the imperial release is made I'm buying one, maybe two.

 

[Janger]

X axis (cross slide) motor mount. It will go on the back side of the cross slide. This is the smaller stepper motor so I'm 3d printing it hoping it will work.

 

[Janger]

Print in progress. 4 hour job. Motor will be attached to the back end of the lead screw. I am also 3D printing a threaded adapter to attach to the lead screw and then go into the drive shaft adapter.

 

[Susquatch]

I wish we could convince our American friends to switch to metric so we could just give up on imperial completely. @Dabbler mentioned a bunch of things holding us back.

It is an interesting story.

I was quite heavily involved in the process of metrication back in the 70s. My boss's boss was a member of Canada's metrication committee. I think he can take single handed credit for convincing the entire North American auto industry to convert to metric - not just Canada but the US and Mexico too. As a senior engineer at the time I got lots and lots of assignments in the process. It was not an easy conversion because it wasn't just fasteners it was everything except the public interface. The US government wasn't interested so we still had to do speedometers and odometers in miles and even worse, in kilometers for Canada too! That crept into safety standards and fuel volume and size and and and. What a total complete mess.

Ironically, Canada actually had the balls to believe that the US would realize they were wrong after Canada showed them the way. Ya right. That didn't happen and it was never gunna happen. That was all nothing but some politician's wet dream in Ottawa.

So now we have imperial lumber, Imperial gauge, Imperial plate and and and and.....

I think the worst situation of all though is commercial construction. Half the building supplies are metric and half are imperial. It's a wonder that multistory buildings don't all fall down! At least cars are metric end to end.

I was born and educated in imperial. I still keep track of my weight and height in imperial. But I am bilingual with temperature, length/distance, fuel economy, speed, and a number of others. Unlike you, I can do decimal numbers or fractions to 16ths just fine. But I have to use a calculator to do 32nds and finer. I'd still like to see both on the display though.

Personally I doubt the US will ever go metric. To do that they would have to admit they were wrong. That ain't gunna happen. To be honest about it, I think the odds are higher that Canada will convert back to imperial...... LMAO! In other words, it is my opinion that we are gunna be metrologicly bi-lingual in Canada for a very long time!

Therefore, my advice is to get used to it and learn to measure fluently in both systems. But I'll still appreciate anyone who insists on one or the other! After all, I'm the guy who would rather that the whole world went octal! I've said it before and I'll say it over again till the day I die - if only humans had left their thumbs out when they first started using their fingers to count!

 

[Janger]

>I'm the guy who would rather that the whole world went octal!

Octal! - we'll have to ban numbering systems discussions

Interesting story John - I agree with you I don't think the USA will ever adopt metric where imperial is an established standard except in certain industries or domains like science.

 

[PeterT]

USA metrification is not as black & white an issue as often believed. Its shades of grey & in constant transition depending on what industry or area of influence.

Busting Myths about the Metric System

This year will be the 45th anniversary of the Metric Conversion Act, which was signed

www.nist.gov

John re discussion in other post, are you putting the drive on the threading lead screw for thread mode & basically power it off & leave power feed confined to existing power feed rod/worm drive mechanical system? I'm curious about the half nuts in ELS mode, does it even matter where you engage - you just find a place of engagement before commencement & it stays put? I assume you can thread in either lathe bed direction?

 

[6.5 Fan]

I use imperial in the shop all the time. All our equipment is older with some metric fasteners, one machine is a combination of both , big pain in the butt. I will be watching for the Rocketronics imperial version ELS. I've cut a lot of threads over the years, all imperial except 1 metric and that did not go well.

 

[Susquatch]

USA metrification is not as black & white an issue as often believed. Its shades of grey & in constant transition depending on what industry or area of influence.

I think it's important to note the authors role in the process. Of course she champions US metrication. That's her job.

I think her article misses the main point. The people of the USA are free to choose what ever they want. The vast majority don't like metric. They prefer an older system developed elsewhere.

Canada and many other countries mandated a public change. The US government didn't do that. They only adopted its use. Nobody forced anyone to change like they did here. Of course, lots of Canadians objected too, but that didn't stop the schools, the road signs, the weather, etc etc etc from being changed. So now we have a mixed up system.

Don't get me wrong, I'm ok living in a bilingual metrological world. But it sure is all F'd up - especially farming.

I think I better stop there because this discussion is bordering on politics. I'd hate to have to moderate myself!

 

[Dabbler]

I'd hate to have to moderate myself!

would that make you an immoderate moderator?

 

[Janger]

John re discussion in other post, are you putting the drive on the threading lead screw for thread mode & basically power it off & leave power feed confined to existing power feed rod/worm drive mechanical system? I'm curious about the half nuts in ELS mode, does it even matter where you engage - you just find a place of engagement before commencement & it stays put? I assume you can thread in either lathe bed direction?

So yes the drive will be on the lead screw and I expect I can engage for rocketronics control or release for manual mode. I'll disconnect the gearing in the headstock to prevent any accidental power engagement on the motor. (some other members commented on doing that I'll take the advice). I don't think where on the leadscrew you engage matters much, you feed with the buttons to touch off x and z and then run the program.

 

[Janger]

I finally have the X motor mount dimensions correct. Dabbler gave me a hand the other day thanks! I had to print this part a few times and it takes 7 hours. This is at the back of the cross slide. I need to fab a M10 to 10mm adapter and position the lovejoy between it and the motor. It’s coming along. I need to make a box for the electronics and finish attaching the z axis motor mount.

 

[jcdammeyer]

Print in progress. 4 hour job. Motor will be attached to the back end of the lead screw. I am also 3D printing a threaded adapter to attach to the lead screw and then go into the drive shaft adapter.

Be careful. Stepper motors and 3D printed plastic don't get along well. Depending on your motor driver and the holding current fall back setting you will likely find the mounting frame changing shape.

 

[Janger]

Be careful. Stepper motors and 3D printed plastic don't get along well. Depending on your motor driver and the holding current fall back setting you will likely find the mounting frame changing shape.

John - do you mean the motor gets too hot and the mount starts to melt/move? I could print with polycarbonate which is higher temperature. Probably a good idea anyway. I suppose I could do a redesign - I think I have some steel C channel which would be convenient.

 

[jcdammeyer]

John - do you mean the motor gets too hot and the mount starts to melt/move? I could print with polycarbonate which is higher temperature. Probably a good idea anyway. I suppose I could do a redesign - I think I have some steel C channel which would be convenient.

The reason my friend Joe made a metal case for our harmonic drive experiment is because he found the motor heat melted the PLA.
Of course a higher temperature plastic is always better anyway with a hot motor. But stepper motors are allowed to get hot enough so you can't hold onto them.
However, in the long run, I'd go to metal mounts here. Even if you weld up the pieces and then just turn/mill the mating surfaces.
Having a foundry is handy. I used couplers from PA with the rubber inserts on these.

 

[Janger]

Argh. That’s not gonna work. Cross slide hits the mount. Motor V5 now printing. Switching to polycarbonate too with 4 perimeters. It melts at 220C instead of 195C for pla. A bit better on temp and it should be stronger. The next mount has a strange appearance only 3D parts undergoing a lot of modifications seem to get.

 

[Janger]

next version...

This print 5.5 hours. On a bambu their slicer says 2.5 hours. I'll be turning into a pumpkin tonight before this finishes... do I want a new printer?

 

[jcdammeyer]

Here's a photo of something similar to what you are doing. The motor doesn't stick out as far as in your version and it's just a metal plate with spacers.

Sometimes it's easier to mount the motor on the front. Especially if backsplash space is an issue.

Myford ML-7 lathe CNC conversion - Part 2: Cross slide

www.jeffree.co.uk

 

[jcdammeyer]

And here's a novel method that might work from the back as easily as from the front. I don't think Jack Churchwood had a face plate so that area under the chuck was never used.

 

[gerritv]

3D printers are a lot like shapers, they take time to do their thing.

I belt drive my X axis on my 1022 lathe, the motor was larger in size than the cross slide would fit over. Lots of cnc milling, including flipping one of the parts. I would simplify this were I to do it again, same plate on the cross slide but just standoffs to mount the motor. I did it the hard way as a teaching thing for the cnc.

gerrit