V-Wheel Adjustment

I did this cut on the path rather than as fill. I’m just running it as a fill now to check the measurements.
Thank you for all you’re help and encouragement.

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Just finished running you’re calibration as it should run and it’s perfect. Thanks again

Awesome!

Regarding the gentleman who was emphatic in his opinion that this wouldn’t work.
The vast majority of those who purchase an X-Carve and participate in this post are of a breed called Makers. We imagine, we design, we create, we innovate, we experiment, we build, we fail and we succeed. We rarely if ever blindly accept the status quo. This is what we do. This is why we’re here. This is why Inventables, X-Carve this forum and its members exude a feeling of excitement that can be felt through the monitor screen. Just sayin.

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@MikeKaplan Nice work man! Looks very promising :+1:

Would you please try running this mod on some hard material? Love to see if this holds up under more brutal conditions.

Got a parts list?

We are all Makers, but some people have more experience than others. Some have more of an engineering sixth sense than others. I initially agreed with him when it seemed like the spring was going to be an active part in day-to-day operations because it would have added flexibility, which is something the machine shouldn’t have.

If you look, you’ll see that he didn’t say anything after it was explained that the spring was not an active part during normal operation. I don’t know if it’s because he had the same misunderstanding as myself or if he felt no further need to speak up, and it doesn’t really matter either way. He’s got more experience with the X-Carve than quite a few of us, including myself, and he’s doing his own innovative things as well, so he’s got every reason to speak up if something looks wrong.

You can’t fault him, and shouldn’t, if he speaks up because he sees something that may end up making the experimenter decide the machine isn’t worth using. We’ve seen people sell their machines because they can’t get them to work, so the idea of a physical machine alteration that potentially increases inaccuracy makes us all a little wary. We are all a part of this community, and none of us ever want to read the words “I give up”.

i wonder if this setup should have it’s own housing that gets attached as a assembly that can work independently from the machine. i am thinking of a 4 sided box on its side made of aluminum or steel. or maybe just 3 of the sides, long side against the machine… or more of a “c” with the open sode of the c bolted to the machine. probably overkill but if it is solid on its own, it should hold up to any stress and keep the wheel shaft rigid.

anyways, i’ll stop trying to predict the possible points of failure and my rambling lol.

Timber - Merbau
Hardness - Seasoned: 7.2-8.6
Accuracy seems good
(paused the cut on circle 13 to adjust one of the v-wheels. Something I couldn’t do while in the middle of a project before.)

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Nice work!

There is a possibility that your idea could work. I am not an engineer but your idea sounds plausible. I have worked with similar wheel adjustment systems in an industrial setting. There seems to be a lot of negative comments about your idea. Folks seem to think that they are experts in the field and think that your ideas will not work. Perhaps the so called experts who say it wont work should show proof of concept.

Mike, do you have specifics on where you got your parts, angles, springs, etc.? Also do you have a video of how you assembled it all?

I wouldn’t doubt that a few people on here are actually engineers. My day job has me doing engineering duties, including the fun parts where I get to play field engineer/technologist and fix problems based on desk engineers who don’t understand reality. I get to play on both the design side and the “oh crap, how can we fix this cheaply and on time” side.

Here’s some proof of concept for you from an engineering perspective, based on the original assumption that the spring was an active component:

  1. We stiffen the X axis and Y axis in order to give the spindle/router as rigid a mounting surface as possible. Any dipping, bowing, or other torsional aspects applied to the router by the bit would change the angle of cut, thus increasing error. This can be seen when doing climb cutting vs. conventional cutting, where the bit either tries to climb off the workpiece or dig itself farther in.
  2. It has also been shown that upcut bits will pull the workpiece up, and can thus pull the spindle down if the proper forces are at work. They work on the principle of the screw mechanism.
  3. Assuming the bit tries to pull the spindle to the back: If the X-carriage had .005" of flexibility up and down, that would cause a pivot point at approximately the center of the X axis due to the rear of the carriage being pulled up and forward as the front of the carriage gets pulled down and back. Assuming the tip of the bit is approximately 5x farther from the pivot point than the V-wheels, that could introduce a possible error of .025". That would depend on the amount of bit sticking out and the height of the spindle. This would introduce a lot of freedom to the bit, which would greatly increase chatter.
  4. Most 1/8" and smaller bits have very little tolerance for inaccuracies like that. I believe GWizard starts to throw errors once the bit is moving fast/deep enough that the bit can cause .001" inaccuracy. If normal feeds/speeds were used on a machine with that much flexibility, bits would break very quickly.
  5. If one removes the forces applied by the bit, however, this system would likely be good for light-duty applications such as running a laser if there was no bouncing left/right during high speed movements.

I hope that is a sufficient proof of concept explanation, based on the original misunderstanding I and others likely had. There may have been some negative comments, but they pretty much went away once it was explained such that the spring wouldn’t be an active component.

We may not be experts, but it never hurts to have this many people with this much experience in so many fields provide feedback.

One of the places that I worked always had at least one “green” engineer. They were there mainly because they didn’t have enough experience to “know” that something couldn’t be done.

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I like the fact that you were able to prove the negative people wrong. You know who you folks are. Always out to prove someone wrong or prove that you know more.

My background/schooling is industrial design. However, I’m the son of an engineer. I’d say I’m in the crossroads between designer and engineer. I took a few engineering classes and found it too… rigid. On the other hand, most designers are too naive. I like to visit both sides back and forth. Dream up something ridiculous, then break it down and make it work. However, I usually build an idea in my head 50 times over figuring out the problems before finally putting it to paper. Hence my post above. Streaming thoughts. It’s generally cheaper to work that way I find ; ) I am sure many, if not all of you can relate.

On a side note, I really enjoy reading and participating on these forms. It’s a top class group here and the ideas exchanged are inspiring. I am glad to be a part of this.

Thanks everyone for being awesome!

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Firstly and most important!!! Happy New Year! I’ve been peering through all the comments on this subject and have made a few observations of my own. The vast majority of participants in this forum are similar in one aspect. We all
want to be supportive of one another, even those that may not come across that way in their writings. The way we express ourselves is based on our enthusiasm and nature to help others. Regardless of the subject matter, we all have a need to express our opinions and whether they come across positive or slightly negative, they are all valuable. As far as making mistakes…that’s what life is all about, learning from mistakes and dumb ideas to eventually settle on innovative and useful solutions to a problem. Whether I’ve done this or not doesn’t matter because the fun is in the trying. It was mentioned the Xcarve is not a toy. I’m 63 years old and to me that’s exactly how I’m treating my experience with this machine similar to an Erector Set when I was a kid. I’ve appreciated….no valued, all the comments I’ve seen in every one of the forum subjects. I came into the forum with practically no knowledge in CNC and in a very short time have acquired enough know how to actually build a machine and produce products with it. So thanks once again to all those who contribute to our knowledge bank. And thanks to Inventables for introducing us to the building blocks of this adventure.

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The engineering professors at the university I go to really stress that we should listen to the non-engineers who have experience. We learn a lot of things in class and from reading, but assembling a real thing is completely different. We have a few design classes where we design and build projects over the semester. Every group has major issues and has to fill out an engineering change notice for each and every mistake… it’s gets us to think before we design or argue a point. Most of the time we’re wrong! Experience is so important.

It’s great to see your idea coming along so well. I have an especially difficult time adjusting my eccentric nuts because my XCarve is in a tight enclosure, so I’m really hoping this works out well. Great work!

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If you think ECN’s are painful in class, just imagine how much more painful they are at a federally-operated research facility with all sorts of hazardous materials. :smile:

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I feel your pain. I had an interview at Sandia in the 70s. I had to walk away from that one. Looking back, glad I did.

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HEY!!! it looks good on paper lol