Link tool path settings

[john_hartman]

Hi all,

I recently completed my first ecabinets kitchen. 47 sheets of pre finished maple. Although everything fit together fairly well I would say that there is tuning to be done.

Here is what I need some help with: note I am using a HSD 2.2hp, .25 compression bit cutting around 4.5 ips, +/- 1 ips or so depending on the part size or operation

1- Dados- is there a way to make these cuts in 2 passes or more? I currently have a .5" dado doing it in 1 pass at full dado depth of .375. I believe these are being in climb, leaving somewhat bumpy uneven wavy cuts.

2- Tenons- These are cut first in one pass in climb (a single rotation of the channel is being cut, so down then back), which is followed by the outline cut in climb as well. I'm cutting almost all the way through in climb. The final pass is done in conventional at full depth. The issue is that the final pass only goes around the outline and NOT back over the tenon. So again I have a bumpy wavy cut which is visible when joined to the cabinet sides.

3- Material thickness- Before the twd file is produced you have the option of changing the material thickness. I have 3/4" ply around .72-.74, 1/2" ply around .46 to .49. This is Columbia Pure Bond with this much variation. I think some of my joints were under sized due to these variances. Is there a general rule to go be here? I can't mic each sheet, then have to reload an entire job... What is the best way to handle variances between sheets?

Many thanks..

[Daniel Vonderheide]

John,

Mortise and tenons do not use the outline settings when cutting. What you will have to do to get multiple passes on these is to change the max penitration for the operation tool. If you set it to .25, it will make multiple passes that only remove .25 of material at a time. You cannot change the direction on the final pass though. Generally you take the average of the materials' thickness and then use this with a .015 or higher fit clearance. Hopefully other shopbot users chime in to give you their experiences.

[Gary Campbell]

John...
I will add acouple things to what Daniel says.

1) You can set Max pen to less for your rout/dado operation, but I would try a test cut at 120ipm first. Lower your RPM to around 10K. I have had better luck cutting dados in conventional direction. Lower the fit clearance

2) Setting from above will improve these cuts also.

3) Like Daniel says you should use an average. I mic part edges from the interior of the sheet and use a low average. In your case, and assuming those were interior not edge measurements, I would use .725 and .49. Easier to hit a couple tight ones with a block than look at loose fits. The variation you describe is pretty normal. Partial depth blind dados were designed to minimize the ill effects of plywood variations.

If you use the above settings and your dado cuts are still wavy, you need to check and tighten up the roller adjustments, pinions/rack of the X, Y and Z.

Have you tried setting dado cut direction to conventional?

If I understand you correctly, you are able to change direction of the final pass, allowing it to travel the same or opposite as the first passes. You may want to decrease the max pen and slow down the speeds for the outline pass, as 1/4" bits deflect agood amount.

The outline and tenon are cutting correctly as you describe. Your problem lies in deflection, either bit or machine, when cutting the dados.

Slow your machine down and make it cut good. Then, and only then increase speeds.

[kevin]

John
I have a question do you mind me asking the size of your kitchen

Or show me the plan I.am curios of yield of sheets seems high

I am still on the fence with the link I would understand if you dont want your plan on the internet

My e-mail claptop@eastlink.ca

Thanks in advance Kevin

[john_hartman]

Kevin-

How can the yield seem high if you have not seen the kitchen plan? Are you doubting that 47 sheets can go in a kitchen? What can say it adds up fast..

[Gary Campbell]

Kevin...
Dont question the yield from eCabs and the Link. As good as any I have seen.

We have the ability to rotate grain (by 45*) to increase if needed. Also a good number of cutting aids to get especially small parts cut well. Parametric settings for Tabs, speed reductions and one click added parts spacing etc. Dont sit on the fence. Nothing under $20K is even close to equal.

[kevin]

I am curios not being a crtic or trying to step on toes

Will share my resuts

Sorry for any typos

[Gary Campbell]

Kevin...
We didnt think you were. You can try this for only a time investment. D/L eCabs and the SB Link Make a batch job using the included standard cabinets. Use the nest button in eCabs to see how it lays parts on a sheet(s). Make a TWD (cnc job) file. Open it in the Link. You can do/see whatever you wish, but cut. All free.

If you play and like what you see, you will learn. After you learn some ask the guys here for more. You can decide to buy the Link only after you like what you see.

[kevin]

Gary

I'am finishing learning the indexer

I want to be more stream lined to have my employees do drawings and just send to the cnc

I.ve fined tuned cabinets parts pro but you have to know cabinets .There is more chance of operator eror .

My question is how long to give or take e-cabinet can be put in to production .Is e-cabinet can be prone to opertor error
I know the rendering takes years

http://www.talkshopbot.com/forum/showthread.php?t=12425

That kitchen I used 24 sheets with the draws

[Gary Campbell]

Kevin...
IF you build a viable seed library of the types of cabinets you wish to build (or you can outsource this), then an employee could select a cabinet from this folder and place it into a batch.

Batch entry allows resizing, so the employee could resize and set the quantity, for each and all cabinets placed in the batch job. When all cabinets are in the batch, save job, press CNC button, adjust material thickness if needed, and you are ready to open in SB Link and cut.

There is no need to spend more than a few minutes to batch a job going out the the ShopBot.

[erniek]

You didn't mention how many flutes your .25 cutter has...


When I first got the link I ordered several 1/4" compression spiral bits, some single flute and some double flute, I got better results with the single flute bits. They can cut faster, with less force, with less perpendicular deflection, and fewer small parts moving because of not enough hold down vacuum. Recently I ran out of the single fluted cutters
and resorted to using the doubles and I'm seeing the same things that
you are complaining about.

[john_hartman]

I'm using a Centurion .25 mortise compression. I never considered a single flute. Anyone else use these for ply. I thought these were reserved for plastics and aluminum.

As a follow-up; I did get better results by slowing the feed rate down for the dados down to 2.5 ips from 3ips. The strange thing is that some tenons turn out perfect while others still show some bumpy/uneven edges. Not nearly as bad though.

For those using a .25 bit what speeds are you cutting at for dados?

Is anyone using a 5/16" compression? What keeps me from a 3/8" are those 1/4" dados, which could be enlarged to 5/16" for bit clearance but not 3/8".

This is only may second project using ecabinets. Both were cut using blind dados. The first was a european frameless and the second with face frames. I think in future that there is really no point to having blind dados/tenons where they will be covered by a face frame. Using full dado would work just fine and save time in the cutting. Is this a bad idea?

[beacon14]

I don't use the link but I cut melamine, MDF and plywood with a single-flute 1/4" compression bit from Whiteside. I have to use a much slower feed rate with the 2-flute compression bits.

[Gary Campbell]

David...
I am slightly confused. You say your feed speeds are higher with the single flute?

John...
The blind dado as we know it is a CNC joinery that reduces the area of a dado, so it should machine faster. My cutting confirms this. It also has the ability to "stop" the dado as to not interfere with an edgebander. If you choose bits carefully (read as larger) you may get a shorter cycle time due to not cutting the tenons, but the gain will be minimal.

To your cut quality, slow down some more till the cut improves. I am still convinced that you have an issue with something loose in the machine. I cut dados in Mel or PF ply at 5.5 ips with a .25 Dn Spiral, faster with the 3/8.

[beacon14]

Gary, not saying the chipload is correct, but I find my machine can't push a 2-flute compression bit through the material as fast as it can push a 1/4" bit when cutting 3/4" material in one pass. My guess is that there is more bit and less space for the chips, and since most of a compression cutter is downcut (except for dados) the chips can't get out of the way fast enough.

If you like you can read that as I can't push the 2-flute bit fast enough to create the proper chipload without the machine bogging down or bit deflection/breaking becoming unacceptable. Single flute bits, however, work fine.

[Gary Campbell]

David...
Dont know if the chipload matters in this case. As long as the bits have good life and you are cutting faster, who cares what the charts say?

It like what Brady says about better hold down with a thicker spoilboard: "It seems counter intuitive, but it works"

[erniek]

I get faster feed rates with the single fluted cutter because my PRT standard has limited cutting force and the double fluted cutter requires
a lot more force to cut with. Maybe with an Alpha machine you could
cut just as fast with the double fluted cutter.

[beacon14]

Dont know if the chipload matters in this case. As long as the bits have good life and you are cutting faster, who cares what the charts say?

Gary, can I tell you a secret? I've never done a chipload calculation. I just go by the sound, advice from the forum, experience, and testing (trial and error).

[Gary Campbell]

David...
I am with you on that one. Never looked at a chart. I have measured a few chips tho. Once I knew what good ones look like, its easy to apply the eyeball method for the chips.

Operators eyes and ears are as valuable as the mic, if not more so.

When in doubt, make a few test cuts. Listen for the music.

[bleeth]

Chipload Chart? What's that? :D