My CNC Arrived

[jteneyck]

Thanks for the update John.  John already knows this as we've been discussing the topic through PMs but I actually have the same machine.  In fact mine arrived a month earlier but have been much slower at putting together because work and life keeps getting in the way.  Seeing your pics though I think gave me the kick in the a$$ to get this thing finally put together.

How do you like the suck-it dust boot.  I was originally planning on printing my own but I now realize I won't have the time so I'm gonna buy one.  I've seen mixed reviews for the suck-it and was considering a couple of options from Etsy.

Can you share what was the stray vector that caused the undesired ramp and how it got into design.  Curious as I'll be flattening my spoilboard soon.

Hopefully I'll post some my pics by this weekend after I do the flattening and grid work.

I'm still not exactly sure what caused the Z axis to ramp down another 0.005" at the end of the run.  I thought it was a stray vector that came in with my imported SketchUp file, but the command was still there even after I deleted that vector and reran the toolpath.  I can't explain it.  So I created a new drawing directly in VCarve; nothing more than a 32 x 48" rectangle, and created a Pocket toolpath to flatten the spoilboard, and it's running w/o issue.  

I did find the root cause of the MDF lifting up.  To resurrect my spoilboard I removed it from the torsion box and cut it into 6" wide strips.  The board was curved concave the minute I unscrewed it.  There must be a difference in tension/compression between the skin of the panel and center.  We never notice it because normally you don't remove one face; it's normally left full thickness and just cut into whatever size is needed.  That confirmed that I needed to screw the MDF down a lot better.  

I took the time to cut a rabbett in the lower edge of each strip so a toilet bolt can slide in between when they are spaced 1/4" apart, and then I drum sanded the side I had tried to flatten to get all the strips back to a common thickness.  That made them even more concave, since I was only taking material off one side.  I drilled 6 holes in each strip, 1/2" deep, for recessed screws.  I screwed them down to the torsion box with 1" cabinet screws and used a 1/4" spacer between the strips as I did so.  So now it looks like this:



I bought the Suckit Pro dust boot.  I had read all the horror stories about how bad it is but other than a little difficulty putting the brush into the recess in the base have had no issues so far.  It is easy to attach/detach for tool bit changes and zeroing the Z axis, and it does a very good job of capturing the dust; it gets pretty much everything.  I'll let you know if something goes wrong but so far I have no complaints other than 1F only provides an assembly video on how to put it together.  I had to stop it and replay it at least a dozen times to see what parts go where.  A simple assembly drawing would have made things much clearer and easier.  

I'm in the process of flattening the spoilboard again, taking 0.005" cuts, assessing, and then taking another pass.  I'm at 0.020" total removed and it's flat almost everywhere now.  One or two more passes should do it.  When that's done I'm going to cut a reference grid into it and then drill some dog holes for locating parts.  

John

[jteneyck]

Oh, wow, I did not think you could supply your own worksurface (torsion box), but now that I see your setup, why not?  That must cost out some cost especially in shipping.

Also good news about the dust collection.

You can buy a frame from 1F but you still need a work table or stand of some kind.  For less than the price of their frame I built the cabinets and torsion box.  I think I spent about $350.  It's massive and very stiff; nothing moves when the gantry stops/starts, etc.  

Yes, I'm very pleased with the dust collection.  The Onieda Dust Deputy is doing a great job of capturing the fine MDF dust and keeping my shop vac's filter from getting coated. 

John

[Lumber Yard®]

The spoilboard will work nicely, I've had a similar set-up on my CNC for years. In my case, I usually don't have to do all of the boards at once when they need replacing, as wear will happen on the boards more frequently on the side you regularly access on the CNC. So, mine are cut and mounted like yours to accept a t-bolt on the underside. I used 1/4" pronged threaded t-nuts on the underside of the main sheet of MDF under the spoilboard strips and then countersunk 1/4" machine screws to mount the strips. Another thing I have always done, is added 1/4" holes on the spoilboard surface for alignment and material holding capabilities. Basically it's just a grid along both the the x and y axis that you can put short 1/4" dowels into and set your work material up against. Although this isn't the best pic, it looks like this and you can see the 1/4" holes in the strips:

   

[jteneyck]

The spoilboard will work nicely, I've had a similar set-up on my CNC for years. In my case, I usually don't have to do all of the boards at once when they need replacing, as wear will happen on the boards more frequently on the side you regularly access on the CNC. So, mine are cut and mounted like yours to accept a t-bolt on the underside. I used 1/4" pronged threaded t-nuts on the underside of the main sheet of MDF under the spoilboard strips and than countersunk 1/4" screws to mount the strips. Another thing I have always done, is added 1/4" holes on the spoilboard surface for alignment and material holding capabilities. Basically it's just a grid along both the the x and y axis that you can put short 1/4" dowels into and set your work material up against. Although this isn't the best pic, it looks like this and you can see the 1/4" holes in the strips:

Thanks.  I can see how only some boards will need to be replaced over time.  Good to know.  I plan to do something similar to your approach with the 1/4" dowel holes.  I could spend a lot of money on precision aluminum bench dogs, but cheap 1/4" dowels look like a good option to me, with no worries if the bit goes where you didn't expect it to. 

John

[jteneyck]

I got the spoilboard flattened after several runs removing 0.005" per pass.  Then I cut some grid lines in it 2" on center, and then I drilled 1/4" diameter holes 1/2" deep at most of the grid intersections.  I'm ready to make some hold down clamps and start using it.  

[Lumber Yard®]

Looks good ... have fun.

[APZ]

Man that looks sweet.  What type of clamps do you plan on using?  

I downloaded the files to print caps and strain relief.  I'm going to start printing those while I wait for mine.

[jteneyck]

Man that looks sweet.  What type of clamps do you plan on using?  

I downloaded the files to print caps and strain relief.  I'm going to start printing those while I wait for mine.

I'm using some clamps I milled on the CNC.  The toilet bolts slide in rabbets cut on the bottom of the spoilboard sections.  Adding another toilet bolt and nut allows you to lift the back of the clamp, which might be helpful on thick parts.  I made some clamps 6" long and some others 8" long.  I can see needing even longer ones to avoid clearance problems with the dust boot in some situations.  



John

[Lumber Yard®]

Cool. You'll find that outside of design, material holding is one of the most critical aspects to producing decent parts. I'm sure you are already aware but the "tab" feature inside of Vectric software helps a lot when cutting profile toolpaths to ensure inside components don't move when they aren't anchored with a hold down, etc. Also, decent quality "carpet" or double sided tape helps a ton. In the end, I use several different strategies to hold material and often use multiple options. HTH

[Cian]

What I think of as I consider adding CNC to my shop...