Carving Names in 2x4 for SB demo

[routerclouter]

I am showing my PRTalpha to about 15 interested people on Saturday night 30 August. Unfortunately, I am a slow, dull, beginning amateur returning to ShopBot and just starting with no carving or mechanical background. I want to V-Carve their names in a 2x4, then cut them out, so they can take home some text they will believe is important. I’ve done their names in PartWorks Vcarve, in a master file that can call their names one after another, depending who turns up. It works OK in preview mode.

Trouble is, I haven’t got a clue about pass depth, spindle speed, feed rate, and plunge rate. Told you I was slow. I have a 3Hp single phase Columbo spindle with a V bit 90 degree half inch. The names will be in Cloister Black BT (fancy Old English, sorta) about half an inch maximum depth if that sounds OK.

With a bit of luck, some of them will move to becoming Buddy buyers, and we can all help each other and not bother the forum too much.


Any advice, except about where to put the 2x4, would be appreciated.

[harryball]

I think I'd start at 14k RPM and .25" passes and just see what happened. Not knowing what bit you have makes figuring a good chipload impossible so I'm guessing. You want to move fast enough to avoid burning and slow enough to avoid making dust instead of chips.

After you see the results, you can make adjustments. Some of my vcarving in foam I always run at 18k RPM in one pass and let her rip. For Cherry, I run at 12k, I found it was burning at higher speeds. I'm never fearful of taking a .25" bite during experimental cutting of wood. If your V bit is very small, perhaps prone to breaking, of course a .125" bite is not out of the question.

I hope that helps, good luck and post pictures.

/RB

[harryball]

Oh, and I'd set my move speeds to 4 ips and my Z axis to 3 ips and adjust from there. That's just me, I'm always a little aggressive on the Z speeds, some guys will stick to 1 or 2 ips on the Z. For small work you'll never reach 4 ips but it is generally safe enough if you do.

Next you'll want to play with your ramping values... err... don't worry about those right now, just enjoy playing.

/RB

[jsfrost]

Can't resist. Put the 2x4 on the Bot.

I generally use a 1/2 shaft 90 degree bit from Rockler. When on sale they are an extremely good buy. and they work well. The heavier shaft allows a more agressive cut. Being basically lazy I start everything at a 12000 RPM setting, and adjust from there depending on appearance.

[knight_toolworks]

keep the rpms down so you don't get any burning. thats my biggest issues with vcarving solid wood sometimes the bit can linger too long. so I stick with 10 to 12k. if your not cutting deeper then .25 do it in a single pass. the wood is soft so you can plunge 3ips but on harder things I would slow that down.
the trick here is to get the wood all the same thickness and a good holddown so you don't have to zero on each piece.

[jsfrost]

John,

I have done a bit more thinking on your project. The 2x4s will be far from flat when you get them and vcarving demands a flat surface. Join and plane the stock flat before attaching to the table.

Run test samples before attempting a demo. When correctly set up, the bot is fully capable of very intracate v carving, but fine lines will be a problem if the table setup and tuning need work. If the fine detail in your font gets lost in cutting, consider a simpler font with more uniform stroke widths as a quick fix. Later, as time allows, tweak your machine to perfection. There's lots of fine tuning advice elsewhere on this forum. Or maybe your setup is fine? The test cut will tell you which.

[routerclouter]

Thank you Robert, Jim and Steve for your help, and Jim for your restraint. The 2x4 will go on the Bot unless it doesn't work and someone else gets hold of it.


The help was great. I'll use it. When you need help, and someone gives it, it's worth a lot, isn't it?

Other Botters might use this or something like it too. Probably they'll do much better. If you've got a bunch of people over, for a party or business or something, it would be nice for them to watch their names being carved and take them home. OK, sometimes the carved names – mine in this case anyway -- are throw-aways, but no word gets a person's attention as much as their name. So it might be something some others might think about.

I am in practice a beginner, so I may have this wrong. Maybe there's negatives in carving them and maybe not everyone thinks their name is that important. But I'm going to give it a go anyway. We gotta learn.

This project has a small programming problem. I made a masterfile which calls the individual name-files, which will be carved one after another in a line along the 2x4. Unfortunately, all the names to be carved are different lengths. How then does one start then next name in the right place?

Here's what I've done. It's not very good. I made individual files for everyone's personal name in Part Works, and saved them with the length of the name (plus about a one inch gap before and after) in the filename, like John6.4.sbp, then added the length to the next start point. With people around me and some beers in me, if I have to code this, I can easily fumble it. The code I've got is sort of:
'2x4MachineMasFi1
'Must add each file value for next offset value
m2 0,0,0
m2 0,0.5,0
FP, Garrison11.5.sbp,,,,,2
m2 11.5, 0.5

[jsfrost]

John,

Assuming you know the end position for each name, as your post suggests, consider editing each Name.sbp file to stop with the router positioned there plus an inch. Instead of the normal end of file M3,X0, Y0,safeZ use M3,X(end+1 inch,0.5,safeZ. There will then be no need for unique moves in the calling file. Make another change to the calling file to input the desired filename and the names can be cut in any order.


One caution. You will need to manually move things back to x and y zero once the cutting reaches the end of your 2x4 or the end of the table. With a little thought an error check can probably make even this automatic.

[knight_toolworks]

myself I would cut the 2x4 to the wanted length manually clamped and make separate partworks files for each name. then replace the wood and run the name you want simple and almost idiot proof.

[bsilva]

Why 2x4's? Cost?

I've found that MDF carves better than most other materials and is dirt cheap. If you're looking at a demo of the capability rather than making something too pretty this might be a way to go. Also, it's going to be a flatter surface than a 2x4 and it's not nearly as picky about feed/speed selection (less likely to chipout).

my $.002 worth..... ;-)

Brad

---------------(Updated)-------------

Of course if I'd read this closer and realized that he did the Demo yesterday, it might have saved me some time... ;-)

[brucehiggins]

You might try a piece of 5/4 cedar decking. Cheap but will look nicer than a 2x4.