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1" pocket measures 9.7"

Birddseedd

Plastic
Joined
Oct 2, 2019
Hello. I am new to Machining. And I'm not sure where to go with my issue here. I drew a one-inch . It is perfectly one inch from the edge of the peice but the square pocket itself measures to small . I did do a spring pass just to be sure. But it seems to be measuring at .97 instead of one inch. I'm not sure where to go from here. And using a grizzly mini Mill with a CNC kit. Thank you for your help
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Well, you can start by throwing that "machine" in the garbage. Get a job in a machine shop and get some real training. Those shitty YouTube videos you've been watching are giving you false hope.
 
Backlash, steps per inch calibration, does the cutter cut undersize. It never fails to amaze me how many people who don't know how to operate a machine attempt to build one...…..seems kind of backwards to me :crazy:

I have a G0704 toy for engraving that holds a .001-.002" that I would love to sell. Problem is everyone I know falls into 1 of 2 categories. They either don't have a clue how to operate it or the people that do know how to operate it don't want anything to do with it.....this isn't by chance....
 
If the cutter was cutting under sized then wouldn't my distance from the end of the part to the beginning of the pocket be off? That measures a perfect 1 inch
 
That's pretty much all Menards sells. Might try to get a entry-level micrometer at some point

Well there ya go, Menards isn't in the machining business.It's a fucking home improvement store.

Would you go to a Ford dealership to buy lumber?
 
Hello. I am new to Machining. And I'm not sure where to go with my issue here. I drew a one-inch . It is perfectly one inch from the edge of the Peace but the square pocket itself measures to smart . I did do a spring pass just to be sure. But it seems to be measuring at .97 instead of one inch. I'm not sure where to go from here. And using a grizzly mini Mill with a CNC kit. Thank you for your help
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Please explain definition of "Peace", and "smart" in relationship to machining trade, this is new to me.
 
Voice to text fail. I fixed it

Try taking the time to sit down to a real keyboard.

And compose real questions with proper punctuation, grammar, and spelling.

You want real answers, requiring our knowledge & time.

So try a wee bit harder.
 
First confirm that it is actually at 0.97" in both axes. If so, accept the fact that you have a substandard machine and must do some "fiddling". Modify your program to add 0.015" and run the program again.

Unfortunately, unless you have made a mistake in either tool path or cutter diameter you will have to do this for everything you mill. Program undersize, measure, correct program for final passes.

IMO 0.015" error is probably typical for that class of machine due to slop and backlash so if you want it to do better you will have to "blueprint" your machine, something some hobbyists have apparently done. That subject is not allowed here (because of the machine involved) so you will need to search hobby forums.
 
Personally, I think you should be happy with the accuracy improvement between your headline and your pictured measurement. Vast improvement.

You need to measure your cutter. For advice on the mill and its operation, seek a home machining site or hobby cnc site.
 
I could accept that and have no problem adjusting what I need to make it work. That's basically what I did before. But I don't think it's that simple. The pocket starts in the perfect position. 1 inch from the end. If it was simply a low tolerance on the Machine then wouldn't that position be off as well? This makes me think that there is something that I'm simply doing wrong and not the machine.
 
I don't think that it's the machine. Wherever it's told to go to as soon as to go to as perfect as what I can measure. I think it's more my inexperience and being able to tell machine to do what I want it to do.
 
I don't think that it's the machine. Wherever it's told to go to as soon as to go to as perfect as what I can measure. I think it's more my inexperience and being able to tell machine to do what I want it to do.

NO. Going where it is told is not the same thing as operation under real cutting loads and I don't think you have the tools or expertise to measure travel accurately. All of those small hobby machines from China have the same issues and owners of them spend many hours trying to reduce slop, flex, and backlash with varying degrees of success.

Your actual cutting error is 0.015" per side which is probably about the best a stock machine of that ilk can do. If it were more capable you would have paid several times the price.
 
I don't think that it's the machine.

You have one of the worst pieces of shit hobby machines on the planet and somehow you're convinced it's not the machine that is the problem? Did the Menards salesman tell you that?

You're quickly learning that machining isn't something that everyone can do by watching 1 YouTube video.
It takes experience, something that 99% of us here on these forums have. Myself I've been machining since 1988. So trust us when we tell you that it's your machine.
 
I don't think that it's the machine. Wherever it's told to go to as soon as to go to as perfect as what I can measure. I think it's more my inexperience and being able to tell machine to do what I want it to do.

How are you measuring it? One way to do it would be to get a decent indicator and some gage blocks. Set zero and "tell" the machine to move 1.000", then check with indicator/gage block setup. I am going to agree with everyone else it is your machine, but if you are serious about this you need to learn how to accurately check things, then you can start trying to narrow down where the error is. Look on craigslist or fleabay for used machinist tools and indicators, names like - Starret, Browne and Sharp, Mitutoyo, Lufkin, Federal Mahr.... One thing chineese you can probably get away with (and you will eventually need them) is a gage block set. Even the cheapies will be far more accurate than you can reliable measure at this point.

these

https://www.mscdirect.com/product/details/06461818

or these for a starter set

https://www.mscdirect.com/product/details/06464051
 
How are you measuring it? One way to do it would be to get a decent indicator and some gage blocks. Set zero and "tell" the machine to move 1.000", then check with indicator/gage block setup. I am going to agree with everyone else it is your machine, but if you are serious about this you need to learn how to accurately check things, then you can start trying to narrow down where the error is. Look on craigslist or fleabay for used machinist tools and indicators, names like - Starret, Browne and Sharp, Mitutoyo, Lufkin, Federal Mahr.... One thing chineese you can probably get away with (and you will eventually need them) is a gage block set. Even the cheapies will be far more accurate than you can reliable measure at this point.

these

https://www.mscdirect.com/product/details/06461818

or these for a starter set

https://www.mscdirect.com/product/details/06464051

Learning how to accurately check things and account for them is what i was hoping to learn when i came here. I understand my machine is not top notch. But I seen it do work and know that it is accurate enough for my uses. I am measuring with a cheap set of calipers. Which are certainly not accurate themselves. And the one edge of my pocket does measure exactly one inch with those calipers. For my uses I can be happy with that level of accuracy.

I need to work on getting blocks and an indicator. For the moment I think I'm going to use engraving tool and move little had one in as you suggest.
 








 
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