Plate Marker speeds, down pressure, and engraver setting

[keefe08]

Hi,
We recently set up a plate marker on our table and have been playing around with it. As of now the engraver really digs in at the beginning and end of each cut, as seen in the picture. Is this typical/expected?
The table is running at 50 ipm, < 10 psi on the cylinder (can easily lift the cylinder when pressurized), and near full open on the scribe throttle. We've played with the post to change the delay at the beginning and end of the path, ended up setting it to 0 seconds but that didn't stop it from creating the divot...
What types of speeds, down pressure, and scribe throttle are y'all running? Should we run the table slow with choked off scribe?

[acourtjester]

I use 5 PSI for the down pressure, two things you can look at one is have the scribe just touching the plate so it is at it's end of travel. and change the tool you use in sheetcam to a rotary so there is no delay in the tools setup

pen tool.jpg

[tnbndr]

I have the same issue no matter what pressure I run for the down pressure. The scribe hammers into the plate pretty hard at the down stroke.

[acourtjester]

I don't remember who posted it but he did not have a down cylinder but just used the weight of the assembly to hold the scribe down on the metal.
I am going to try this soon.

[Brand X]

I use a cylinder, but with a Mini slide rail added. Just floats along for my style of of air markers. I tried the air down force PSI setup, and decided there has to be a better more consistent way of doing things.. My engraver is a smaller Dotco, and nothing will be gained by adding more down force. Also have a cheap .250 die grinder that will dig harder..You can change to milling bit styles of your choice that way.. Gives you a very good range in setup..(cheap as heck too..)

[Brand X]

This is what I get with my dotco air marker.. I broke my die grinder bit somehow, (just sitting on my bench) so I can't show you what a get with that setup.. I use .3 delay, and .23 pause at the end of cut. Pretty much does not need messed with at all,when changing thickness etc.. I could fine tune it a bit, but I like it as is..

[keefe08]

aCourtJester - From other threads I have come across I had the impression you didn't want to run out of travel, that way you don't have to worry about material warpage. But having the height set so the tip is just touching could be a solution. Yup your swap tool types will provide the desired results.

Brand X- Jezz thats nice on so many levels, you really have to look to see where the tool starts. I'm not following how you're set up. If you don't have an air cylinder how does the tool retract between paths (or alternatively extend at the beginning of a cut)? You said you've still got it hooked up to a cylinder, if you're not pressuring the cylinder down what is it doing?

[Brand X]

I have it hooked up the same as most people,but I added a small linear slide to the tool holder. It allows the air tool to float on the surface of the metal being marked. The air cylinder is mounted solid on the Z-axis mounting plate, but does not move with the Z up, and down..( The air slide does move up, and down) The weight of the tool does all it needs as far as down force. There is no need to set pressure other then to move the cylinder down. I could have 100 pounds, and it would not make a bit of difference on the pressure on the tip. Tip never drags/ hangs up/etc.. Only setting is delay in start, and stop in Sheetcam. Mine stays a .23 and .3 seconds. I leave the tool at 100 psi. (my marker works better at a bit higher pressure) They can be a bit finicky on starting the thing. Down force pressure is about 20 or 30 psi. Flow valves opened all the way. I can put a $20 die grinder in the same holder for a deeper type scribe line. Very versatile. (IMO) It's same setup for a vinyl knife.. (floats)

I run about 30 ipm with the dotco scribe, and way faster with the die grinder.. 100 ipm is more of the norm. there..

When I first hooked mine up, and ran pressure to set the down force, I knew right away that sucked for my air scribe. Read something Luke said from Candcnc, and it clicked that I can probably do better with a slide. I had one laying in my junk box, and solved all my problems dicking with other way.. I have some stops to limit travel depending on what I am scribing.. Just keeps the stroke from moving all the way up/down, if i don't need to..

[motoguy]

I have it hooked up the same as most people,but I added a small linear slide to the tool holder. It allows the air tool to float on the surface of the metal being marked. The air cylinder is mounted solid on the Z-axis mounting plate, but does not move with the Z up, and down..( The air slide does move up, and down) The weight of the tool does all it needs as far as down force. There is no need to set pressure other then to move the cylinder down. I could have 100 pounds, and it would not make a bit of difference on the pressure on the tip. Tip never drags/ hangs up/etc.. Only setting is delay in start, and stop in Sheetcam. Mine stays a .23 and .3 seconds. I leave the tool at 100 psi. (my marker works better at a bit higher pressure) They can be a bit finicky on starting the thing. Down force pressure is about 20 or 30 psi. Flow valves opened all the way. I can put a $20 die grinder in the same holder for a deeper type scribe line. Very versatile. (IMO) It's same setup for a vinyl knife.. (floats)

So the air slide moves the tool holder down onto the part. The air slide actually drives further than it would for a solid-mounted tool (ie, would punch through the plate, if solid mounted). However, the tool holder itself is mounting on a linear slide, on the "tool holder plate" of the air slide. So, as the air slide moves down, the scribe/marker touches the material, and stops...even if the air slide keeps going (assuming the air slide doesn't move more than the travel allowed in the linear rail). The weight of the tool/mount on the linear slide provides the only downforce.

Do I have that correct? I like the idea of running the same setup for a scribe/plate marker/die grinder/vinyl knife!

[Brand X]

Yes, correct.
You could add weight/spring tension to fine tune the tool down force, but I have found it unnecessary so far.. I adjust the stops on the up slope/down slope,(air slide travel) just to keep the longer die grinder from running out travel with the one inch mini slide.. Simple to adjust/ make.

[keefe08]

Hey Brand X,
A picture is worth a thousand words! That's a nifty idea and apparently gives great results, thanks for sharing it.

[Brand X]

Hey Brand X,
A picture is worth a thousand words! That's a nifty idea and apparently gives great results, thanks for sharing it.

Here is one more.. Really hard to see too many flaws in normal viewing.. Not without magnification. Really does show me just how well my table works now. (not this cut though) If you look at the date on a penny, you get a good idea of the size of the gecko's feet..

[motoguy]

I'm going to add my scribe to my table, BrandX style. Any suggestions on the size/type of rail I want to get? I'm completely ignorant when it comes to rail types/sizes. Something like this, and I'll cut it to the length I need (4-7 inches, probably)?

https://smile.amazon.com/Anycubic-Minia ... rail&psc=1

[Brand X]

1 inch if Travel works well too.. More would certainly not hurt anything. I have stops to adjust for other things.. If I stick with the same stroke travel (Not the same as the slide travel) The timing always stays the same, and zero adjustment is needed. Plug, and play that way.. :)That type of rail is certainly good enough.. I kind of like the wider LW series for low profile, and one of the better all position load setups. I just have a cheaper box slider on mine for now..


http://www.nskamericas.com/cps/rde/xbcr ... _Guide.pdf

[chadmjohn]

Hey Brand X,
A picture is worth a thousand words! That's a nifty idea and apparently gives great results, thanks for sharing it.

Here is one more.. Really hard to see too many flaws in normal viewing.. Not without magnification. Really does show me just how well my table works now. (not this cut though) If you look at the date on a penny, you get a good idea of the size of the gecko's feet..

Is that with the air scribe? Most of the ones I have seen (but I've only seen a few) leave rather rough set of marks like a centerpunch was used 1,000 times (basically what these are). Is the one you are using good for 'finished goods' (think engraved items being sold to tourists ) or would you not use it for that? Do you mind stating the brand of scribe you are using?

[acourtjester]

Here is the one I used (very little) and is the one many use on their tables too.
https://www.ebay.com/itm/152447547178?e ... Sw0bpcq5dd
These have been around for a long time and used for different tasks too.

[djreiswig]

More related to the original topic, but a precision regulator makes the downpressure more consistent.
viewtopic.php?f=100&t=25655&p=157239#p157239

[chadmjohn]

Here is the one I used (very little) and is the one many use on their tables too.
https://www.ebay.com/itm/152447547178?e ... Sw0bpcq5dd
These have been around for a long time and used for different tasks too.

Thank you for the model and recommendation, that's an excellent confirmation as the CP9361 is what "the one' that seems to be referenced most in my "looking around" (I won't call it research )