Bed Zero and tool changing

[ken_rychlik]

First off I want to vounteer GARY to help everyone do this if you are not set up already.

It makes tool chages fast and easy.

I mounted a block off to the side of my table. The prs has the Y motor on one side but the opposite side has more clearance to allow this. A prt may be more challenging to make this work on.

Then I cut a short piece off of the original Z zero plate and after surfacing the block to the same level as the spoilboar, mounted the plate and wired it to the control box.

My tool change file brings my machine to an easy location to change bits, then takes it automatically to the zero spot to take care of that. I don't have to fool with getting out the plate and putting it under the bit, so that is nice.

A complete bit change and back to cutting is just a few minutes to make happen and zeroing can be done with a sheet on the bed.

When the bed is surfaced, the plate will come off and the block surfaced as well.

I am putting a picture of the zero block.

Kenneth



660

[dlcw]

Kenneth said: "I mounted a block off to the side of my table. The prs has the Y motor on one side but the opposite side has more clearance to allow this. A prt may be more challenging to make this work on."

Or a PRS 96x60 where the full 60" width is utilized for 60x60 baltic birch sheets.

I'd be careful volunteering Gary for more work. He has done so much to help the Shopbot community. It's time for all of us who have received help from Gary to pass this knowledge on to the next generation of users and let Gary have a breather. :-)

Don

[ken_rychlik]

I was mostly teasing about vol-un-teering him. I hope shopbot gives him a killer deal on his new machine.

None of the normal files will work out of the box. They don't know which output you have turning on DC, Vac hold down, spindle, ect..

Also the spots you would use for a zero block or bit changes will most likley be different than mine.

Kenneth

[thewoodcrafter]

So Kenneth does this mean you got the Link working and you are zeroing to the bed for your bit changes in the middle of a file?

[ken_rychlik]

Yes.

Everything but the Vac hold down system shuts off and the machine jogs to the bit change location and pauses. Then after changing the bit it jogs over the plate. After zeroing itself it goes to work. Router and DC come back on and away it goes.

Kenneth

[thewoodcrafter]

Congratulations!

Way to go!

This will be way more productive than the old drawing in V-Carve.

[ken_rychlik]

Thanks

This job I have running now was even more challenging. I had half the parts cut in vcarve and finished it with ecabinets. Now that was cause for some head scratching.

Much to my surprise it all fit together. lol

Kenneth

[Gary Campbell]

Kenneth...
You know I have to say this....

THAT IS JUST WRONG!!!!!

Gary

[ken_rychlik]

Should I stand on the roof while I do that ??

[ken_rychlik]

Just an update to this thread. I had many freeze ups on the ecab files and after doubling the ram on the control pc those troubles all went away. There were some run time 5 errors causing the control console to shut down and that went away also with the upgrade of Ram.

It had 512mb and I put in 1 gig and it's happy. I went ahead and orderd two one gig sticks for it just to be on the safe side.

The regular files in the SB 3.6.14 sofware WILL run ecabinets. I didn't want to zero to the top of the material because of variations in material thickness. The other issue with the OEM setup for toolchages was they automatically turned off all switch outputs. I have everything turning on and off automatically with relays and switched on and off in the post processor of vcarve pro and wanted to leave that working. The Vac hold down comes on at the start of the file and stays on during the bit change so the sheet won't get bumped. In my file so,5,1 turns on the vac hold down and so,5,0 turns it off. The Dust Colector come on with momentary swiches. I tied into my remote control switches for this. The command so,7,1 pause 1 so,7,0 is used to start the DC and so,8,1 pause 1 so,8,0 turns it off. The toolchage files had to be modified for this as well. I wanted the Dust collector to stop, router to stop, the machine to jog to a comfortable spot to chage bits, Then jog to the zero spot, zero the changed bit, and when it finishes that, the router and DC come back on and it starts cutting with that bit.

At my request Gary helped get me set up on the toolchage that would work with a zero on the bed and make the block on the side for zeroing the bit pretty much automatic. Ryan at 'bot was very helpfull and was able to get me running, but without the bed zero and getting the tool change fast and easy. I'm sure he doesn't want to build custom files for each customer and they are worried about safety as well.

Something that came up during my chats with Ryan, was that the spbarts file got to much info in it when uploading the latest software. If you take that file and rename it before a fresh install, you can always go back and get any custom or modified files you have in there.

My machine is a simple PRS standard with a 4g board and only one Z with a PC router. The only mods to the machine are the relays to run the router, vac hold down, and DC.

Anyone wanting coppies of the files I used to make it run (with Garys permission) is welcome to them. They will have to be modified for your machine though. Your zero block may be in a different place. You may want to change bits somewhere else. You may not want the files to turn on and off your accessories. Your DC or Vac hold down may be on different outputs.

Also I have a "vacuum the table" routine set up in the sheet footer of the link that after a pause for me to get the parts off of the table, it will run around with the bit just above the spoilboard and clean itself up. This is just a copy of the spoilboard surfacing routine that I modified. I entered that I have a 4 inch bit and instead of a negative number to surface the board I gave it a .2 above the bed. It takes about 5 minutes to clean itself, but it sure beats a broom or an air hose.

I thought it was just going to be a plug and play kind of thing and I guess thats possible, but if you want the machine to pretty much take care of itself, it takes more effort.

I am running smooth now and a happy camper. The only thing Gary did wrong is that he got me running so smooth that I may not even need that air drill.

Kenneth

[thewoodcrafter]

Glad to see everything is work that good.

I like the table cleaning idea. I need to do that.

Welcome to E-Cabinets and the Link.

[loriny]

This may well be a stupid question. I have still been zeroing to top of material but the job I will be starting to cut tomorrow has some varying thicknesses in the melamine.
I am just wondering if it matters how many commands are in my C9 file. Currently I am set up to park machine at the end of the table between sheets. Do I just add the commands after this to do my Z-zero to the table?

[ken_rychlik]

There are some z shift commands that need to be in there.

I did a block off to the side of my main table to allow for tool changes, mid sheet.

Gary helped with the files, but if you want coppies of them (no warranty) they are free.

Kenneth

[loriny]

Yes I have the z shift files. I was just curious if I can add them after my jog to park between sheets command.
Lorin

[ken_rychlik]

I emailed you a copy of mine and you can just compare the info in them to see what to add where. Hope it helps.

Kenneth

[taskins]

Kenneth-I'd love to gget a copy of that too. I am just now noodling out something to try to do just that.

Thanks

Tim

[englert]

Just a view point on zeroing to the bed versus the top of the material. I say view point, because it seems everyone is different, just as everyone builds their boxes different and of course, their way is better.

Variations in material thickness is an issue, and I think, even more so if you zero in at the top of the material. We zero in at the top of the spoil board. And since we also use a 1/4" wasteboard or sacrificial board, we adjust our Z zero for that with a variable called WASTEBOARD. The ZSHIFT variable relates to the material thickness that you established in eCabinet's and possibly adjusted as you exported or created the CNC file. So ZSHIFT adjusts Z0 in theory to the surface of the material. I say that since the consistency between sheets is inconsistent. But what is important is that the plunge depth is consistent. Your tenon thickness, in particular should be (I believe) more consistent and doesn't vary because of Z0 being set to actual material thickness.

Another plus to ZSHIFT is that you can use that to adjust depth of cut. Possibly on the first sheet you recognize that you're cutting too deep or shallow. Change the ZSHIFT value for all of the sheets, recut the first sheet (if need be) and continue on. There's no need to go back to eCabinets and recreate the CNC file or adjust anyother offset variables that you may have in the ShopBot. I'm not familiar with those.

So for us, Z zero on the table surface works well. Your call.


Dennis L. Englert

[ken_rychlik]

Thanks for the info Dennis.

I went to your class in New Braunsfels (sp) many years ago and all I can say is you KNOW your stuff well. I think that was in version 4 of ecabs.

For those that want to see or use my tool change, zshift files, they are free BUT without warranty. :D My web link is below my name in my post and you can email me though there.

Every shopbot seems to be set up a little different, so I'm sure some tweaking will be required to make them work on your machine.

For anyone wanting to use the stock shopbot files, Ryan at SB can walk you through it to zero off of the table if that is your desire.

Whatever you use ALWAYS AIR CUT to try it out first.

Kenneth

[loriny]

Got it going. Cut a couple sheets so far. The dadoes are perfect. Thanks to all who have posted info and sent files. It is appreciated.
Lorin

[Gary Campbell]

When we first started the beta testing of the SB Link and the initial development of the MTC files our primary information source was "the Guys from Thermwood". Their method of zeroing to the bed was different than we were used to, but after an explanation of the reasoning and how the ZSHIFT actually works I found much more acccurate and consistant joinery could be produced.

As time went on and manual toolchanges were added, I noted discrepancies and inconsistant tenon dimensions. Changing back to a single tool, with an initial zero to bed, eliminated the problems. In my mind, the problem lies almost completely in plywood thickness variation. My zero to top of material and allowing for ZSHIFT was every bit as accurate as my zero to bed. However, the surface I was zeroing to was not consistant.

In my opinion, Kenneth has the best setup for completing a manual toolchange. He uses a zero block, off the material, to rezero his additional tools to the same height that the original used.

I have added this feature to my Vectric postP's using the output material thickness = &zshift and then zero to bed, same as eCabs files. This allows conventional design from top of material with added accuracy of zero to bed.

Another "workaround" similar to Dennis' above for tenon/dado depths is to use the wasteboard feature for adjustments to Z on the fly. Here is a quick version on how to do this:
Zero to bed
VA Z height to -.25
set wasteboard = .25 (actual wasteboard is not used)
when wasteboard prompt appears decrease wasteboard thickness by amount you wish to cut deeper, increase by amount shallower.

Thanks again to the crew in Dale, IN for giving us some great tools.

[bleeth]

Regarding thickness of plywood and other substrates:

Consistancy is a thing of the past!! If you are using, for example, prefinished maple or just about any other typical plywood substrate the thickness will not only vary from sheet to sheet it will vary within the sheet. Some of the stuff out there today looks like a washboard!! Even of you are using veneered MDF you can find variation, although much less. There are several of my suppliers that I won't buy melamine from as the product they sell not only has an inconsistant core density but a varying thickness as well. Most of the institutional jobs we do specify laminate on plywood. That means that the thickness of the stock varies and there is nothing I can do about it and remain competitive.
For this reason we do all our zeroing from the top so dados and boring depth is consistant and just cut deeper by a fraction to cut the parts out.

[ken_rychlik]

Dave,

My thinking is backwards from yours.

I don't care how consitant the dado depth is from the top. I want the distance from the bottom of the dado to the bottom of the sheet to be correct.

This is the only way the outside of the cabinet will be the correct size.

Mine are mostly full dado and that may affect my opinion more. Blind dados are going to need both sides of this puzzle correct.

Kenneth

[loriny]

I cut a dozen or so sheets now with z-zero to table. My blind dado tolerance has never been this good. Previously they were either to tight or to loose. The other advantage is now I can operate with a lot less through cut. Previously I was set a .008 now I am running .004 and could probably go less.
Lorin

[thewoodcrafter]

If you don't zero to the bed it is pretty much a hit or miss to get the tenon to fit in the dado correctly with the usual material thickness variations.

Thermwood has a lot of development into this system and it works great just the way it is, zeroing to the bed.

[Gary Campbell]

Dave...
I am going with Ken, Lorin and Roger on this one. Much more consistancy and accuracy with zero to bed. If you design for .75 (nominal) and set dado depth to .25. THe result is all dados are cut .5 above the bed. Even if thickness is off by .050 on both sides cabinet will still be at design width

Also, no rezero is needed when changing to another material thickness. We often cut 30 sheet jobs with up to 4 material thickness'. Big time saver.

Time for you to jump into the 21st century with eCabs & the SB Link :D

[bleeth]

The difference is probably in the different ways we cut and assemble our parts. For now I'll stick to top z but I may run a couple with table z and then change my mind.

Gary: The closer I get to retirement the more I think of building projects with 19th century tools and non-engineered materials. It would be nice to really feel wood again!! Maybe something along the lines of a cold molded Lobster Boat to cruise the Sound in. Now wouldn't that be :cool:.