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FelixPQ
01-30-2012, 07:46 AM
Hi,

say for example one as pretty large pattern to carve (say 14.5" W x 60" L x 0.7" D). What I'd like to do is something like this:

first pass: remove as much material as possible using a 1/2" ball noose bit as fast as possible. (assume I can create the intermediate patterns if necessary)

second pass: remove as much material as possible using a 3/16" ball noose bit as fast as possible and start where the previous pass left us. (assume I can create the intermediate patterns if necessary)

Final pass: use the 1/16 ball noose bit at low speed and low depth of cut to create as nice a finish as possible and start where the previous pass left us of course.

Is something like this possible and if so would you have any suggestion on how?

Thanks,
Felix

jaroot
01-30-2012, 07:52 AM
I would guess that it is possible but the end result will be a much longer carve. The last carve will take just as long as it would if you didn't make the first 2 carves. And the last pass on "optimal" will give you as good of a finish as the machine can produce. I don't think that you would gain anything by the multiple passes.

Just my 2 cents worth.

FelixPQ
01-30-2012, 08:22 AM
jaroot,

I would believe you're right for the time issue but the additional pass would in my mind be a mean to improve the overall quality of the result base on the fact the 1/16" bit would be less loaded if it had less material to remove. Less load equate basically to less movement (however tiny) and more accuracy and problably better finish as well.

You can add to all this much less risk to break bit.

Regards,
Felix

LittleRedWoodshop
01-30-2012, 08:44 AM
What you are proposing is not necessary with a CarveWright. But if you have to try something like it ... run the carve as we always have .... then move the crank handle down a quarter turn and run it again. The second pass will just remove a few thousandths of material.

Alan Malmstrom
01-30-2012, 09:22 AM
The beauty of the carvewright is the carving bit moving rapidly back and forth to obtain detailed carvings. When it makes small passes back and forth it shaves of a little at a time kind of like shaving a wall of wood. And getting the detail with just the tip of the bit at the bottom. It would be useless to use a big bit to shave off the top layer and then go back with the tip of the carving bit to get the detail of the surface when you can just do it all at once in my opinion.

Alan

mtylerfl
01-30-2012, 10:44 AM
Hi,

say for example one as pretty large pattern to carve (say 14.5" W x 60" L x 0.7" D). What I'd like to do is something like this:

first pass: remove as much material as possible using a 1/2" ball noose bit as fast as possible. (assume I can create the intermediate patterns if necessary)

second pass: remove as much material as possible using a 3/16" ball noose bit as fast as possible and start where the previous pass left us. (assume I can create the intermediate patterns if necessary)

Final pass: use the 1/16 ball noose bit at low speed and low depth of cut to create as nice a finish as possible and start where the previous pass left us of course.

Is something like this possible and if so would you have any suggestion on how?

Thanks,
Felix

Hi Felix,

For what it's worth...

What you are describing is what we do with "brand-x" CNC machines, that are not quite as automated as our CarveWright machines. It is common to run a roughing pass with a larger bit to remove the bulk of material, then follow that with a finish pass using a smaller diameter bit that can reach into the remaining nooks and crannies that the large bit could not fit into, as well as removing excess material left intentionally over the entire surface of the project during the roughing stage. (A few thousands of an inch are purposely left on the surface in case the rough pass chips a little...the finish pass cleans that up after the roughing.)

Now, the main reason this is usually done is not to save time necessarily, but rather to protect the smaller diameter bit from breaking. Most of the smaller diameter bits available for other CNC machines are more fragile and don't have the same cutting depth capability as the CarveWright 1/16" tapered bit. The CW bit is designed to be more robust and less fragile than your commonly used smaller-tip bits for the rest of the CNC world. Having said that, you certainly COULD use the CW bits in any other CNC machine, if desired!

Achieving a time-savings by performing a roughing, then a finish pass can be "iffy". It's true you can set the speed and feed rates reasonably fast for the larger bit and remove a lot of material rather quickly on other CNC's. However, the final finishing pass will normally take just about as long as the CW does using just the 1/16" tapered carving bit in one pass. Yes, I can increase my feed/speed rates for the finish pass on my ShopBot CNC machine, BUT it seldom saves much time. Why?...because the Z-axis motion slows everything down anyway. For example, if I set a feed rate of 3 inches per second for the finish pass along with a small stepover of say, 6% or 8% (to get a fine quality finish on a relief carving), the machine really will NOT actually reach a speed of 3 ips because of the combination of the small stepover and Z-axis moves (it might achieve as little as 1/2" to 1" ips actual speed/feed).

I often experiment with speed/feed settings on projects that I run roughing/finishing passes on. The software I use for generating the toolpaths with (Vectric Aspire) has an accurate time estimator, just as the CW software does. The times are LONGER when running both a roughing and finishing pass for a project. The overall time will vary depending upon the detail contained in the carvings for the project. If I need to use a 1/16" Ballnose to get all the detail to carve nicely, the carve time is usually going to be about the same as the identical carving performed with the CarveWright machine. If I can get away with using a 1/8" or larger ballnose bit (for less detailed carvings), obviously the carve time will be faster (which is true for the CarveWright machine as well). The main time-saving gain is at the cutout stage of a project...I can run the cutout profile vectors and pocket cuts a lot faster on the ShopBot than on the CW (which has preset speed/feed rates)...mainly because I normally use a 1/4" spiral bit to perform the cuts on the Bot. You can push a 1/4" bit pretty fast through the material.

For the present, the CW and Designer software simplify a lot of procedures and shield us from certain "complications". We don't have to concern ourselves too much with speed and feed rate settings, RPM settings, toolpathing and all that. Clean and simple operation is the goal of the CW machine, so practically anyone can run it (if they can follow directions, that is!:)). That's not to say later down the road that a future CW software package wouldn't add more advanced features for those who may "need" it, and hopefully understand, the various manual settings they may have to deal with.

cestout
01-30-2012, 03:52 PM
For the 5/4 top option on my "Treasure Chest" project (in the Pattern Store) I recomend that and have the files included to do that. YOu put the piece thru twice for a two sided carve.
Clint

FelixPQ
01-31-2012, 05:39 AM
mtylerfl,

basically, I agree with you, I understand the CW was designed more specifically for carving with a small bit in mind and Designer was probably optimise for just that and I can add to that ease of use.

My concern is more about other task then carving per say, I saw many post where folk said they broke their 1/8" strait bit. I have to say I just bougth my CW and I have only one 1/8" bit and not to mention, it cost me as much to get it here then the bit is worth so I'll be very careful not to break it. The first real project I want to do is shown below and basically there is no carving, just cuts and a lot of holes. I have no idea of what will happen with this kind of work and can't find much if any info on all other type of cuts then carving. Ah! Yes, I forgot to mention, designer is basically useless to setup drilling hundreds of holes, I was lucky to find a utility that does it via ai2mpc but then again it seems that either ai2mpc or designer itself offset the hole pattern by a small amount in both x and y. I bougth both the dxf and stl importer and I would have thought especially with the dxf importer that I would be able to select all my holes and setup a drilling operation for them (as you probably can with Aspire for example) or things like pockets on this kind of geometry but designer seems to have no clue of what to do with closed geometry.

It's probably true that I don't have to be concern with multiple pass, multi bits when carving stuff is involved but for all other types of operation the machine can do, it seems to be another story. Though I'll do some test before the real parts trying to find out how cutting through a 3/4" board is done by starting with small depth of cut but it would have been nice of LHR to mention somewhere how things are done for other types of operation then carving and also what happens with different bit size especially since we have no control on speed, stepover, plunge rate, etc?


Thanks for your time,
Felix

jaroot
01-31-2012, 08:17 AM
Now that is an entirely different question. Yes a lot of us have broken the 1/8" straight bit. And yes multiple passes help, help solve that problem. Those passes can be programmed in the "cut through" dialog. Another way to help with the 1/8" carving bit is to only use it if the detail of the piece requires it. I recently bought the 3/16" cutting bit and it is much more robust than the smaller one. Of Course you can't make the same tight cuts with it. I don't think anybody has broken the carving bit.At least not while using it to "carve" with.



My concern is more about other task then carving per say, I saw many post where folk said they broke their 1/8" strait bit.
Felix

dbfletcher
01-31-2012, 08:25 AM
I think one of the most common reasons we see here for broken 1/8 bits is users not following to +7 rule. The board comes out from under one of the rollers, tips up..... snap... $$$ down the drain.

FelixPQ
01-31-2012, 09:25 AM
jaroot,

if I understand correctly, if I setup a cut through operation, the default is to make the cut in a single pass, right? It's basically at the opposite of what it does in the case of carvings, which is almost "fool" proof and well implemented from what I can see. If we forget to set the max depth of pass we can quickly get in trouble and brake bit or worst. Does anyone know if the quality setting as any effect on other types of operation compared with carving (which provides a little control)?

No wonder the software doesn't know much if anything about dados, pokects, holes patterns and similar stuff.

Many thanks, at least I know what to do now,
Felix

henry1
01-31-2012, 10:31 AM
Here the problem I am having with line accross the pattern //I have change the Z motor//the ribbon// loosen a bit the Y belt//I had a roller on the sand belt stift I change that //the Y and the Z easy to push on travel// put recondition bearing I was able to put a little bit of grease in them // still having same problem see the pic

henry1
01-31-2012, 10:35 AM
I have sent pic to LHR and still waiting for an answer any help appreciated
Henry

mtylerfl
01-31-2012, 12:50 PM
jaroot,

if I understand correctly, if I setup a cut through operation, the default is to make the cut in a single pass, right? It's basically at the opposite of what it does in the case of carvings, which is almost "fool" proof and well implemented from what I can see. If we forget to set the max depth of pass we can quickly get in trouble and brake bit or worst. Does anyone know if the quality setting as any effect on other types of operation compared with carving (which provides a little control)?

No wonder the software doesn't know much if anything about dados, pokects, holes patterns and similar stuff.

Many thanks, at least I know what to do now,
Felix

Hi Felix,

I don't know if you have had a chance to read through the Tips & Tricks yet. Many of the functions you may find useful are described (multipass Cut Paths, dados, pockets, etc.)

Here's a couple links you may want to check out...

Mulitpass settings... http://www.carvewright.com/downloads/tips/CarveWrightTips&Tricks_Sept08.pdf

Pockets/Dados... http://www.carvewright.com/2010CWweb/learn/videotips/jan11tips.php
http://www.carvewright.com/2010CWweb/learn/videotips/feb11tips.php

Here's a Bird Cage I designed for CarveWright back in 2008 (before DXF and STL importers were available). Something like 256 holes were drilled.
http://store.carvewright.com/product.php?productid=18638&cat=261&page=2

You can download and view the PDF instructions for the project, if you think that may be helpful to look over as you proceed with your bird feeder project.

DickB
01-31-2012, 12:57 PM
I don't think anybody has broken the carving bit.At least not while using it to "carve" with.
I just broke one a couple weeks ago, but I believe it was defective. I had swapped out my old bit which was showing signs if dullness, and the new one broke after one 5 min. carve. I went back to the old one to finish the same project, same wood, and many others. So I don't think it was the wood, project, or machine - it was the bit.

FelixPQ
02-01-2012, 06:11 AM
mtylerl,

I've read a few of them including those. I bought the machine expecting I was buying a desktop CNC specialised in carving. What I didn't expect is that it would be such a pain to realise other operations then carving. By this I mean that if you want to make a pocket for example you basically have to create the "toolpath" on your own manually and the way it's done in designer is very ackward compared to how it's done in any other 2D and or 3D drawing package. This is one of the reason I bought the DXF importer, such that I could create these kinds of toolpath in a familiar program.

Then again, my first try was with the bottom part of my bird feeder project, my first design required a pocket area in the center of the part and I even added another pocket a little deaper such that the tray would fit nicely in this second pocket providing an easy way to assemble it accuratly. Also I added the circles to provide precise location for the dowels or rods and a lot of circles for the location of "drain" holes. It took me about 15 minutes to create the drawing in my prefered CAD program. When I imported this 2D DXF into dxf importer I realised something was wrong, my program translated the drawing as spline elements which import nicely in many other programs but the dxf importer seems to be unable to do use correctly this type of elements. To make a long story as short as possible, I finally managed to create a file that the importer could manage correctly, I was in for a big surprise, when I selected all holes the same size and depth and click on drill, beside the cursor changing to a small cross, nothing else happen. After a few second, I realised designer wasn't much help to say the least to create a drill operation from a circle or circles. So back to the drawing board, I decided to create directly the toolpath for the holes, ie. a circle with the proper radius to compensate for the bit radius.

From now on, here's what I'll do for anything other then carvings, I'll draw my (vector) stuff in a cad program, use a CAM program to generate the toolpath I need, export these tollpath to a dxf file and finally importing it in designer. I'll admit it's still a mess but it's much less time consuming then doing all of it in designer.

Your right, as your Bird cage proves it, one can do quite a bit with the machine even without software add-on but what a pain.

Regards,
Felix

gapdev
02-01-2012, 02:30 PM
if I setup a cut through operation, the default is to make the cut in a single pass

I thought you could change the default - Depth, # of tabs, etc?

Kenny

cestout
02-01-2012, 03:34 PM
Looks to me like that would be easier to create in Designer than to go to the trouble of converting it. The problem would be that Designer does not hav e an array copy feature. I know not why the programmers chose not to include that in the public version.
Clint