some quality issues with my cuts using vectric-

Post general information and questions relating to Cut2D in this Forum.
User avatar
NACC
Vectric Apprentice
Posts: 59
Joined: Fri Apr 15, 2022 11:09 pm
Model of CNC Machine: Shark 510HD
Contact:

some quality issues with my cuts using vectric-

Post by NACC »

Hello guys- I was hoping for some quality control help with my vcarve and a few issues i'm having. I just ruined a maple cannon carriage that took me a while to do- using desktop version 11.006, Next Wave Shark SD120. There's 5 photo's below, each one describing the issue I'm having. I would welcome any feedback. I'm a "beginner" user and still trying to wrap my head around basic functions. I've watched countless hours of tutorials- my head is spinning. I know these issues are due to something I'm overlooking.

1) set pocket toolpath to cut .75 dia. with 1/4 end mill. it always comes up short. I see this only when cutting round pocket toolpaths.

2) the test block in the photo is a profile toolpath with 1/4 radius corners to fit into the pocket toolpath with 1/4 radius corners- it should fit like a puzzle, but the radius corners don't fit at all. I'm using a .25 end mill. the profile is set to cut "outside the vector", the pocket is set to "offset climb"... The final piece will be brass, I'm using the wood as a test. why don't the 1/4" corners fit?

3) this photo is in reference to # 2- this block with 1/4 radius should fit the pocket with 1/4 radius corners?

4) like #1 above, set pocket toolpath to cut .75 dia. with 1/4 end mill. always comes up short.

5) cutting a 1" deep pocket set to 16 passes- 1/4"end mill, pocket toolpath. the tool cut beyond vector in this corner! now I need to buy and cut a larger piece of brass and try to line this profile up, zero and re-cut it. why is the tool digging into this corner like that when only making 1/16" deep passes?

Thank you! :D
Attachments
1) set pocket toolpath to cut 1" dia. with 1/4 end mill. always comes up short.
1) set pocket toolpath to cut 1" dia. with 1/4 end mill. always comes up short.
2) test block is a profile toolpath with 1/4 radius to fit into the pocket toolpath with 1/4 radius- radius doesn't line up.
2) test block is a profile toolpath with 1/4 radius to fit into the pocket toolpath with 1/4 radius- radius doesn't line up.
3) this block with 1/4 radius should fit the pocket with 1/4 radius corners?
3) this block with 1/4 radius should fit the pocket with 1/4 radius corners?
4)set pocket toolpath to cut .75 dia. with 1/4 end mill. always comes up short.
4)set pocket toolpath to cut .75 dia. with 1/4 end mill. always comes up short.
5) 1" deep pocket set to 16 passes- 1/4"end mill, pocket toolpath. tool cuts beyond vector in this corner.
5) 1" deep pocket set to 16 passes- 1/4"end mill, pocket toolpath. tool cuts beyond vector in this corner.

User avatar
TReischl
Vectric Wizard
Posts: 4599
Joined: Thu Jan 18, 2007 6:04 pm
Model of CNC Machine: 8020 48X36X7 RP 2022 UCCNC Screenset
Location: Leland NC

Re: some quality issues with my cuts using vectric-

Post by TReischl »

I am not berating your machine, cause any CNC machine is better than no cnc machine. . . .

But, what you are describing is all machine issues. Rigidity, flex, etc.
"If you see a good fight, get in it." Dr. Vernon Johns

User avatar
scotttarnor
Vectric Wizard
Posts: 941
Joined: Fri Aug 30, 2019 11:40 pm
Model of CNC Machine: Piranha XL , Shark HD520
Location: La Crosse WI

Re: some quality issues with my cuts using vectric-

Post by scotttarnor »

I would have to agree with TReischl, looking at photo #5 the witness marks it looks like you doing an inch cut in 10 passes, I don't try any more than .06 in maple with my sharks , of course this will also depend upon your feed rate.
I would try slowing your feed rate down and you will probable see better results, don't forget to adjust your speed with your feed.
Last edited by scotttarnor on Wed Apr 20, 2022 3:15 pm, edited 1 time in total.
Scott T

@scottscnc

User avatar
adze_cnc
Vectric Wizard
Posts: 4329
Joined: Sat Jul 27, 2013 10:08 pm
Model of CNC Machine: AXYZ 4008
Location: Vancouver, BC, Canada

Re: some quality issues with my cuts using vectric-

Post by adze_cnc »

This thread should be renamed: some quality issues with my cuts using my machine

Look at the g-code produced by the program. If the g-code is specifying a, for example, 0.75 dia hole and you are not getting one from your machine how can it be Cut2D that is the problem?

User avatar
NACC
Vectric Apprentice
Posts: 59
Joined: Fri Apr 15, 2022 11:09 pm
Model of CNC Machine: Shark 510HD
Contact:

Re: some quality issues with my cuts using vectric-

Post by NACC »

TReischl wrote:
Wed Apr 20, 2022 2:43 pm
I am not berating your machine, cause any CNC machine is better than no cnc machine. . . .

But, what you are describing is all machine issues. Rigidity, flex, etc.
I was wondering that- I'm used to working with my bridgeport mill and lathe, where if you set the dro to .757, you'll get a cut at exactly .757 lol. this is my first desktop cnc and I was actually surprised to unpack it and see the entire chassis made from delrin (or some plastic material) vs aluminum or steel. I suppose there's some pro's with plastics that aren't susceptible to temperatures like metal is, but the amount of flex in the the whole system had me scratching my head. I guess I'll just need to adjust the measurements to make it work- but I don't know how i'll get those corner radii to line up tho. this sucks, I bought the cnc to cut carriage plates out for my cannon business- up until now, I've been doing it by hand and it's very tedious- this cnc would've really saved me time but so far, it's not panning out as well as I had hoped. :(
www.northamericancannon.com

User avatar
NACC
Vectric Apprentice
Posts: 59
Joined: Fri Apr 15, 2022 11:09 pm
Model of CNC Machine: Shark 510HD
Contact:

Re: some quality issues with my cuts using vectric-

Post by NACC »

scotttarnor wrote:
Wed Apr 20, 2022 3:08 pm
I would have to agree with TReischl, looking at photo #5 the witness marks it looks like you doing an inch cut in 10 passes, I don't try any more than .06 in maple with my sharks , of course this will also depend upon your feed rate.
I would try slowing your feed rate down and you will probable see better results, don't forget to adjust your speed with your feed.
I can see how you'd think 10 passes when looking at the right corner ridges, for some reason there's ridges that would logically bring you to that conclusion- if you look at the right side however, you'll see the 16th" cut lines. in any case, I'll try slowing down the feed rate like you mentioned, maybe it's coming in too fast and loading up in the corners and it's pulling the tool into it. just weird that it didn't do it in the right corner, only in the left corner. thank you.
www.northamericancannon.com

User avatar
NACC
Vectric Apprentice
Posts: 59
Joined: Fri Apr 15, 2022 11:09 pm
Model of CNC Machine: Shark 510HD
Contact:

Re: some quality issues with my cuts using vectric-

Post by NACC »

adze_cnc wrote:
Wed Apr 20, 2022 3:13 pm
This thread should be renamed: some quality issues with my cuts using my machine

Look at the g-code produced by the program. If the g-code is specifying a, for example, 0.75 dia hole and you are not getting one from your machine how can it be Cut2D that is the problem?
maybe the machine, maybe the software... I couldn't tell you if it's an issue with either one, hence the question. is it a setting i'm overlooking in the software? is it deviation in the machine? the machine makes square pockets exactly as they should be (1.99 " pocket on the screen = 1.99 pocket with my calipers in the wood) when I run the gcode and watch it cut circles on the screen, there's no way for me to measure the cut in 3-d after it's done- I have to go back to 2-d and use the measuring tool, but then I'm simply measuring the vector as I created it, not as it was cut in the screen preview (tho both should be identical). with a profile cut, I can choose "inside", "outside" or "on" the vector line- I can't do that with a pocket toolpath as far as I'm aware. so if my diameter pockets are consistently off by a few hundredths (as seen in my photos)- perhaps it's my lack of experience using this particular function in the program rather than the machine being off- as I mentioned earlier, it makes properly measured cuts with straight lines. maybe you can tell me if I'm not using a function properly while setting up a toolpath?
www.northamericancannon.com

User avatar
scotttarnor
Vectric Wizard
Posts: 941
Joined: Fri Aug 30, 2019 11:40 pm
Model of CNC Machine: Piranha XL , Shark HD520
Location: La Crosse WI

Re: some quality issues with my cuts using vectric-

Post by scotttarnor »

If you toggle this on in the 2D view it represents the actual cut then you can measure your actual cut.
Screen Shot 2022-04-20 at 12.48.56 PM.png
Scott T

@scottscnc

User avatar
FixitMike
Vectric Wizard
Posts: 2173
Joined: Sun Apr 17, 2011 5:21 am
Model of CNC Machine: Shark Pro Plus (retired)
Location: Burien, WA USA

Re: some quality issues with my cuts using vectric-

Post by FixitMike »

My guess is that the pocket was drawn with square corners and cut with a 1/4" diameter end mill, resulting in 1/8" radius corners. The divot in the corner is the result of machine deflection, drive looseness, or a controller setting.
Last edited by FixitMike on Wed Apr 20, 2022 7:42 pm, edited 1 time in total.
Good judgement comes from experience.
Experience comes from bad judgement.

User avatar
adze_cnc
Vectric Wizard
Posts: 4329
Joined: Sat Jul 27, 2013 10:08 pm
Model of CNC Machine: AXYZ 4008
Location: Vancouver, BC, Canada

Re: some quality issues with my cuts using vectric-

Post by adze_cnc »

And you are 100% sure that your 0.250" end mill is really that size and not 0.249" ? Or 0.248" ?

User avatar
NACC
Vectric Apprentice
Posts: 59
Joined: Fri Apr 15, 2022 11:09 pm
Model of CNC Machine: Shark 510HD
Contact:

Re: some quality issues with my cuts using vectric-

Post by NACC »

FixitMike wrote:
Wed Apr 20, 2022 7:35 pm
My guess is that the pocket was drawn with square corners and cut with a 1/4" diameter end mill, resulting in 1/8" radius corners. The divot in the corner is the result of machine deflection, drive looseness, or a controller setting.
i designed the rectangle with 1/4" outside radius corners.
I went over all the axis points- it's a new machine and everything is tight.
While using my bridgeport, I've experienced the material pulling the tool from my collet when milling, especially when using a large endmill at low rpm- but I was only cutting 1/16" at around 16,000 rpm with a fairly new 1/4" endmill. i can't imagine it loading up like that in the corner, but i guess it's possible with these flimsy machines.
www.northamericancannon.com

User avatar
NACC
Vectric Apprentice
Posts: 59
Joined: Fri Apr 15, 2022 11:09 pm
Model of CNC Machine: Shark 510HD
Contact:

Re: some quality issues with my cuts using vectric-

Post by NACC »

adze_cnc wrote:
Wed Apr 20, 2022 7:37 pm
And you are 100% sure that your 0.250" end mill is really that size and not 0.249" ? Or 0.248" ?
I'll mic the endmill when I get home this evening... but I would think if the 1/4" endmill isn't true to size, then I'd also see a deviation on straight line pockets- but i'm not.
www.northamericancannon.com

User avatar
Rcnewcomb
Vectric Archimage
Posts: 5887
Joined: Fri Nov 04, 2005 5:54 am
Model of CNC Machine: 24x36 GCnC/WinCNC with ATC
Location: San Jose, California, USA
Contact:

Re: some quality issues with my cuts using vectric-

Post by Rcnewcomb »

This looks like a machine issue. As mentioned before:
Slow down your feed rate
Switch between climb and conventional to see if the issue moves to a different place
Change between offset and raster to see if the issue moves. With Raster try Profile pass Last and profile pass first.
Ramp your plunges
- Randall Newcomb
10 fingers in, 10 fingers out, another good day in the shop

User avatar
NACC
Vectric Apprentice
Posts: 59
Joined: Fri Apr 15, 2022 11:09 pm
Model of CNC Machine: Shark 510HD
Contact:

Re: some quality issues with my cuts using vectric-

Post by NACC »

FixitMike wrote:
Wed Apr 20, 2022 7:35 pm
My guess is that the pocket was drawn with square corners and cut with a 1/4" diameter end mill, resulting in 1/8" radius corners.
adze_cnc wrote:
Wed Apr 20, 2022 7:37 pm
And you are 100% sure that your 0.250" end mill is really that size.... ?

I think you both nailed it- :D

first- adze_cnc, I just measured the 1/4" end mill, the shank is .25, but the blade part is only .22 - significant difference there!
second- fixitmike, for the trunnion block, i created a rectangle with 1/4" outside radius HOWEVER, for the trunnion block pocket, it WAS a straight rectangle (like you mentioned) that I assumed would be a .25" inside radius because I (incorrectly) measured the tool shank instead of the blade!
so, the trunnion block indeed had a .25" radius but the pocket inside corners only had whatever the radius a .22 tool cuts at a corner.

I'll need to make some revisions with the design and test it on some scrap, but I believe you two nailed it here. much thanks! :wink:

still doesn't explain the deviation in the round pockets- but i'm sure it's something i'm not doing right in the software.
btw, first-adze, when i mentioned "a quality issue- i was referring to the quality outcome of my project, not with the vectric software. I can see how my title could be misleading. :wink:
www.northamericancannon.com

User avatar
FixitMike
Vectric Wizard
Posts: 2173
Joined: Sun Apr 17, 2011 5:21 am
Model of CNC Machine: Shark Pro Plus (retired)
Location: Burien, WA USA

Re: some quality issues with my cuts using vectric-

Post by FixitMike »

NACC wrote:
Wed Apr 20, 2022 11:07 pm
first- adze_cnc, I just measured the 1/4" end mill, the shank is .25, but the blade part is only .22 - significant difference there!
second- fixitmike, for the trunnion block, i created a rectangle with 1/4" outside radius HOWEVER, for the trunnion block pocket, it WAS a straight rectangle (like you mentioned) that I assumed would be a .25" inside radius because I (incorrectly) measured the tool shank instead of the blade!
so, the trunnion block indeed had a .25" radius but the pocket inside corners only had whatever the radius a .22 tool cuts at a corner.
I
A .22 dia. tool cuts a .11 radius inside corner.
Good judgement comes from experience.
Experience comes from bad judgement.

Post Reply