V- carving

[wegner81]

I have been tring to V-carve some small lettering on some buisness card holders. I am having a couple problems. The letters are about 5/16 high. I am using a 60 degree bit and have adjusted my ramp speeds. Is there a way to v-carve without having a flat bottom in the letter. The letters are so small that they run so close together that there is hardly anything left. Which leads me into my next problem I am having depth variation, 3 lines, same tool paths. new machine. one line was noticable deeper than the other two. thanks for any advice

[sawdust535]

If your using PartWorks, just don't check the "Flat Depth" box. Also, you can try kerning (spacing) the characters farther apart.

[cnc_works]

Also, many router bits, though they appear to come to a point, really run in a small orbit on the tip so you can never get a flat bottom no matter what.

For that small a letter you could get a real engraving bit for not much money from BitsandBits (www.bitsandbits.com (http://www.bitsandbits.com)) that has the capability to make a true v-groove bottom.

Donn

[sawdust535]

Donn
I just visited your website. Nice work! What are the size and depth of your boxes?

[cnc_works]

Thanks, George. Most of them are approximately 3.5" X 7" X 2 3/4" deep. For a long time I was limited on my Z by my smaller CNC, but now with the bot, not much of a limit. Of course, one piece boxes only make sense in smaller sizes because of the material wastage. Mine are about at the limit for me before I start figuring a way to optimize material usage.

Donn

[harryball]

I made some very small engravings of a company logo in cherry for name door plaque holders. The smallest letters are less than 1/4".

I tried with a V bit and was frustrated with the results. I had to get a "real" engraving bit with a .01 tip. It worked wonders and turned out great. This post reminded me I need to post some photos... I'll try to do that today or tomorrow.

/RB

[bill1]

RB,
Where did you purchase your engraving bit? I also have been frustrated with text that is 1/4" or less also if you don't mind what is the feed and speed you use,
Thanks
Bill.

[harryball]

I used bits from Onsrud. I also upgraded my PRT Alpha to the 7.2:1, that made some difference as well. The new PRS Alphas should be up to the job out of the box.

For such a small job the xy move speeds will never get very high, in my case I had them set to 1 ips with the Z speed set to 3 ips. For RPM I played around and found the cherry to cut clean with minimal burning around 12k RPM. This will vary depending on the material. The RPM's seemed high to me at first, but when I slowed down the edges became more ragged. I was concerned about burning but didn't see any until I reached 15k RPM or more. 12k seemed a good compromise in the end.

I should note that I'm using a 4HP HSD spindle as well.

/RB

[bill1]

I will check Onsrud out now.
thanks
Bill.

[wegner81]

Thanks for all the help and great advice again. I will try a few adjustments with the spacing first and post some pics. Thanks again! You guys make the learning curve alot easier!!!!!

[harryball]

I added my post to show and tell with the name plate holder. It uses the engraving bit and carves small letters.

/RB