New to Shopbot and having some issues.

[Moore412]

Hi! new to shopbot and this forum hope this is the right section to post in, just becoming aquatinted with the programs and such. I have a few questions for all you experienced people out there who are familiar with these problems were running into:

1.) What material and bit are best to be used for cutting the monogrammed letters and initials? Also, what tool path is the best to use for this?

We have tried all sorts of materials such as MDF, Birch and plywood. The problem we have noticed is that the pieces splinter really bad and we have tons of time in sanding them down. Surely this isn’t that scenario for every cut is it? We have been using the 1/4” straight bit for cutting these. When I talked to a tech at shopbot they mentioned a compression bit? What is the best bit for cutting letters?

Another problem we have been having it when using the vine font the loops are getting broken off even when using a ton of taps.

2.) When doing the engravings what is the best type of bit to use? We ordered .005 tip solid carbide one flute straight engraving bit with 60 and 30 degree angles. Is there something better than these bits to use? Mainly we are engraving plexi and wood.

Any help would be great we are new to this and trying to figure it out but rather than wasting more wood in trying new things out figured it was best to just ask.

* We have a PRS Alpha with 4.5 spindle

[Kyle Stapleton]

Post pictures, it will help a lot.

[scottp55]

Wow, Lots of different VINE fonts. Like Kyle said pics would help and put a dime or something in pic for scale. Some of those vine fonts don't look like they would carve well. Only have one engraving bit and it doesn't cut wood nearly as nice as a 3 Flute VBit. You should be able to get a no sand or minimal sand finish like this.

[Moore412]

Here are a few pictures of the splintering I'm referring to.

[bleeth]

The old timers around here will tell you that the secret to getting good results in what you are trying to do is learning, learning, learning! Like any artisan work, when you start there will be lots of issues. There are so many factors involved in getting this kind of thing to come out right it is amazing:
1. What bit (as in EXACTLY what bit-what brand, what part number or precise designation)
2. What feed speed
3. What spin speed
4. exactly what material

I will tell you that in my experience engraving bits are best at very shallow depths. That is why they are called engraving and can perform best in plastic that is made for engraving. Often better results are had with V-tools that have 2 cutting edges and even then identical tools from different suppliers will have different results in different materials. Veneered product can have it's own issues as the veneer is so thin that cross grain cuts can "frazzle" it very easily. There are, again, so many different veneers and also how well they are laid up on the substrate can cause a real difference.
MDF comes in many different qualities and they are far from equal. The big box store stuff is rarely the best for detail work. Rather you are better off with a higher quality (although not necessarily much more expensive) from a cabinet or plywood distributor where you can get Sierra Pine products, for example. If you plan on doing a lot of detail carving in MDF you may want to look into higher density ones that have less air in them than standard MDF. A good product for this, although very heavy and not something you want to breath in is Extira-a product made for exterior use that is quite high density (read heavy!) but carves terrific.

[gc3]

foto 1 use compression bit as suggested or a left hand flute bit will give very little tearout on bottom

foto 2 3d toolpath? on something like this i always apply 2 coats sealer first to stop tear out like that sometimes cut cross grain depends on wood specie

[Moore412]

In terms of compression bits I was looking on onsrud side and they have several pages and types of compression bits. What is the best type to use from cutting lettering and things out of wood?

Sorry I am a newbie and have tons of questions. We have been trying things out just to learn but trying to get help in terms of what bits to buy because wasting money on the wrong one will be a costly mistake and some of the compression bits I am seeing cost over $200.00 on the onsrud site.

[gerryv]

Sometimes when folks start out they choose to use cheap bits on the assumption that they are likely to make mistakes or break some (a reasonable assumption). This may not be true in your case but you need to remember that the piece of wood does not know if you're running a top-of-the-line machine or something else. first and foremost, it will interact with the bit, good or bad and respond accordingly. While other elements come into play like table flatness and hold down, decent quality, sharp bits are more forgiving and capable. I'm no expert on this but it's advise I've received and seen offered from others more knowledgeable.

Along with the good advise you're getting on bit "type" you might also look into what's called the "chip load calculator" Tech support or others on the forum can tell you where to find that - it relates to finding the optimal combination of things like the speed you're cutting at and spindle RPM among other things.

[gc3]

In terms of compression bits I was looking on onsrud side and they have several pages and types of compression bits. What is the best type to use from cutting lettering and things out of wood?

Sorry I am a newbie and have tons of questions. We have been trying things out just to learn but trying to get help in terms of what bits to buy because wasting money on the wrong one will be a costly mistake and some of the compression bits I am seeing cost over $200.00 on the onsrud site.

guys...welcome to the club...as DR said very well...you gotta figure it out, every shop is different

i went thru major learning curve, people helped me to a point...best you spend time to educate yourself...many forums out there to learn from...https://www.facebook.com/VectorStudio22

[coryatjohn]

You can also use a micro-tool (like 1/32nd) to outline your cuts if you have the time. They frazzle the edges a lot less.

[scottp55]

Jeffrey and Amanda, On second picture if I focus just on "the" it looks like a 3D cut like Gene thought, But If I focus on the whole thing it looks like an 1/8" deep pocket cut using an 1/8" bit. Good optical "delusion". Can you tell me if the letters are pocketed like the front board shown, or if the letters are raised like the board in back? The info Dave asked is what we need to help out.

[gundog]

1) Speed and feed always include this in any question of this type.
2) Type of tooling used.
3) Exact material you are cutting and thickness.
4) Depth of cut on each pass.
5) Hold down method.
6) Pictures.

These are the things people need to know to help you and the things that go wrong. You can call the tooling manufacturer and get a recommendation for tooling for your exact job I have done this many times with good results. There are some really experienced people on here that can help you if you provide all the information above in your posts.

Mike