Piranha Issues

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sdiccenso
Posts: 4
Joined: Wed Jun 03, 2015 8:30 am
Location: St. Petersburg, FL

Piranha Issues

Post by sdiccenso »

I got a new Piranha a few months ago. It came with V-Carve Desktop. I have been playing with the software to learn it. I have noticed a few things. The first is:

I am making small things both 2D and 3D. The 3D stuff seems to be ok. 2D stuff not so good. Circles in particular. I am engraving and am getting flat spots on the top and bottom of the circle as well as on the sides sometimes. The circles range from 1" to 2.5". See my attachment. The circles are 2" & 2.25". I have been working with Next Wave to figure this out. The sent me a new driver for the Piranha but to no avail. Anyone experience this and if sower you able to resolve.

Also have had occasional and erratic Cuts, almost like it had a mind of its own.

Anyone experience this with their Piranha?

Any suggestions would be greatly appreciated.


Steve
Attachments
IMG_1250-1.jpg

Mimbler
Posts: 76
Joined: Sat Nov 29, 2014 5:37 pm

Re: Piranha Issues

Post by Mimbler »

I have a piranha and haven't seen these issues, but a couple of ideas to check:

1) Any chance the material is moving?
2) The machine will deflect if you drive it too hard. I've found the default tool feeds are 2 or 3 times higher than what I like to use for good results.
3) Anything around, under, over, next to the machine that could cause it to bind or it's cables to bind?
I'm sure others can add to this list of things to check,
Mike
sdiccenso wrote:I got a new Piranha a few months ago. It came with V-Carve Desktop. I have been playing with the software to learn it. I have noticed a few things. The first is:

I am making small things both 2D and 3D. The 3D stuff seems to be ok. 2D stuff not so good. Circles in particular. I am engraving and am getting flat spots on the top and bottom of the circle as well as on the sides sometimes. The circles range from 1" to 2.5". See my attachment. The circles are 2" & 2.25". I have been working with Next Wave to figure this out. The sent me a new driver for the Piranha but to no avail. Anyone experience this and if sower you able to resolve.

Also have had occasional and erratic Cuts, almost like it had a mind of its own.

Anyone experience this with their Piranha?

Any suggestions would be greatly appreciated.


Steve

tyger_purr
Posts: 10
Joined: Thu Jul 16, 2015 9:19 am

Re: Piranha Issues

Post by tyger_purr »

I see the flat is also inside the dish around the horse. This would hint to me that it is not likely binding on an obstacle or cord.

Mimbler's suggestion of material movement or driving it too hard (too fast) are good to check.

I'd also suggest checking to see if the router is secure in the clamp or the carriage is loose allowing the router to shift off track.
I run a CNC Piranha with a Bosch Colt.

sdiccenso
Posts: 4
Joined: Wed Jun 03, 2015 8:30 am
Location: St. Petersburg, FL

Re: Piranha Issues

Post by sdiccenso »

I have previously check the router and it is properly secured. I don't think the material is moving as I fasten it with the included hold downs as well as 2-sided tape. I will have to check the cables but there is nothing under, around or next to the machine. I am using very slow speeds like feed = 5"/min.

What about where the machine is placed. I have it on a Craftsman tool cart. I don't notice anything while the Piranha is running.

Next wave asked me to do some things that I need to set up. I am going to cut some circles and squares. I will repeat these several times while varying the feed speed.

I am at a loss beyond this as I have no previous experience with CNC.


Thanks,

Steve

Mimbler
Posts: 76
Joined: Sat Nov 29, 2014 5:37 pm

Re: Piranha Issues

Post by Mimbler »

Well, I'm out of ideas for now. Please keep us in the loop as you and Next Wave get to the bottom of it. You'll enjoy the machine when you do. It is very accurate and capable. I use it to make shell inlays for the guitars I build and the precision is amazing.
Mike
sdiccenso wrote:I have previously check the router and it is properly secured. I don't think the material is moving as I fasten it with the included hold downs as well as 2-sided tape. I will have to check the cables but there is nothing under, around or next to the machine. I am using very slow speeds like feed = 5"/min.

What about where the machine is placed. I have it on a Craftsman tool cart. I don't notice anything while the Piranha is running.

Next wave asked me to do some things that I need to set up. I am going to cut some circles and squares. I will repeat these several times while varying the feed speed.

I am at a loss beyond this as I have no previous experience with CNC.


Thanks,

Steve

Eagle55
Posts: 788
Joined: Sun Nov 20, 2011 8:44 pm

Re: Piranha Issues

Post by Eagle55 »

I have a Shark HD (original) so I don't have any Piranha experience but I am going to go out on a limb and suggest that there looks like there is something physical going on. I don't think it is a software issue. The fact that you can see the same indications of the flat spot in the dish out area that look similar to the flat on the round engrave surrounding the image. There is also what appears to be a mirror image of the error on top and bottom. I am going to say that you are looking for a physical problem at or related to any "T-nut" that the lead screws travel in, such as loose mounting or binding of them. I am not familiar with that version so I don't know where or how they are configured but that is the impression that it is giving me. It may be backlash related but binding or loose I think are more likely. You might make sure that you are well lubricated in those areas. I use silicone spray for all of my sliding/moving points.

Roger
Last edited by Eagle55 on Tue Aug 18, 2015 9:57 pm, edited 1 time in total.
CNC Shark HD ~ Control Panel 2.0 ~ Windows 7 & XP
Located in West Tennessee near the Tennessee River
http://www.eaglecarver4.com

Mimbler
Posts: 76
Joined: Sat Nov 29, 2014 5:37 pm

Re: Piranha Issues

Post by Mimbler »

In agreement with Roger; check your preview carefully. If this problem isn't showing up in the preview on your computer monitor, it isn't a software problem.
Mike
Eagle55 wrote:I have a Shark HD (original) so I don't have any Piranha experience but I am going to go out on a limb and suggest that there looks like there is something physical going on. I don't think it is a software issue. The fact that you can see the same indications of the flat spot in the dish our area that look similar to the flat on the round engrave surrounding the image. There is also what appears to be a mirror image of the error on top and bottom. I am going to say that you are looking for a physical problem at or related to any "T-nut" that the lead screws travel in, such as loose mounting or binding of them. I am not familiar with that version so I don't know where or how they are configured but that is the impression that it is giving me. It may be backlash related but binding or loose I think are more likely. You might make sure that you are well lubricated in those areas. I use silicone spray for all of my sliding/moving point.

Roger

sdiccenso
Posts: 4
Joined: Wed Jun 03, 2015 8:30 am
Location: St. Petersburg, FL

Re: Piranha Issues

Post by sdiccenso »

I have reviewed the preview and the file looks fine. I am going to make sure it (the Piranha) is clean and lubricate it ( i have some dry Teflon spray that was recommended). I will then go over the entire framework to make sure all is tight. It may have to wait until the weekend as I am back working as of yesterday. I got to pay for this somehow. Just kidding but I am working again as I am a contract Tech Writer. I hope this is my last gig.

I mentioned that I have it on a mobile, Craftsman cart. The cart is pretty stable but I am going to move it to a more stable surface. Would it make any difference if it was anchored down?


Thanks,


Steve

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Bob
Posts: 1252
Joined: Sun Aug 08, 2010 3:35 pm

Re: Piranha Issues

Post by Bob »

Steve,
The Teflon spray works well. Be careful to wipe off any excess on threaded rods. If you spray on too much, it will form a thick wax-like buildup on the threads. If this happens the T-nuts will jam, or give erratic results...Guess how I learned about that...

Now that I'm on the subject, you should probably check to see if too much has already been applied.
Bob
"Focus"
Antonie Van Leeuwenhoek (Developer of the microscope.)

Mimbler
Posts: 76
Joined: Sat Nov 29, 2014 5:37 pm

Re: Piranha Issues

Post by Mimbler »

Steve, I don't see a way for the mobile cart to be causing this problem. As long as the top is solid and flat so it isn't putting the machine in a bind, it should be fine. I have mine on a workbench that isn't one of those rock solid installations, but I just added a layer of birch plywood on top (just laying there) to insure a nice flat support,
Mike
sdiccenso wrote:I have reviewed the preview and the file looks fine. I am going to make sure it (the Piranha) is clean and lubricate it ( i have some dry Teflon spray that was recommended). I will then go over the entire framework to make sure all is tight. It may have to wait until the weekend as I am back working as of yesterday. I got to pay for this somehow. Just kidding but I am working again as I am a contract Tech Writer. I hope this is my last gig.

I mentioned that I have it on a mobile, Craftsman cart. The cart is pretty stable but I am going to move it to a more stable surface. Would it make any difference if it was anchored down?


Thanks,


Steve

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