Tiling WITH 2-sided machining

[mfirlott]

Having a hard time getting my head around combining these two subjects. After my mistake I describe below, I've tried to draw it out on scratch paper and now I've got a headache. Any help would be appreciated.

I made a walking stick that is a 2-sided carving but of course I have to also tile it on my Stinger I. It's 2 tiles long (T1 and T2), each 31" long along the Y-axis, and I after flipping and machining side 2, I had an alignment issue and the two halves did not line up.

I have done tiling before by making a dowel hole on T1 and T2 then sliding along the Y axis to place T2 in the dowel hole. No issues and that works just fine when I do just one-sided machining. But of course, now...when I flip the piece over to machine side 2, I don't have enough alignment holes and Side B is out of alignment.

I cannot seem to figure out how to get my 3 alignment holes onto T2 so that I can both slide it down for tiling alignment and then once side A is done, flip it over into the alignment holes for 2-sided machining. How do I get my 3 alignment holes into T2 while I'm machining T1? Or is that just not possible?

Any ideas???

[garylmast]

I've have done several dozen two side projects now and my habit is to either trim the material because of glue-up or grab a piece of material that is close to what I set as the size in the original setup. Maybe because I'm lazy, I don't have to go back and resize and recalculate, I've quit using the dowel holes method and setup up a jig to set the material in. Depending on how thick the model is, the jig is as simple as shooting some brads in some scrap wood to the spoilboard. Of course, the model will have to be secure. If the model if very thick, I'll make the jig into a 90° so I can screw into the model. I also center the datum instead of setting it on the corner, again because of the material difference. The jig will only take a minute or two.

If you read the post below, everybody except me uses the dowels, BUT they will have the actuate size of material. You can also tell by the diagram why I center the datum. In your case, if you use a jig, you should be able to just slide the model instead of trying to figure out where your dowel holes are suppose to be. I know I'll get some jazz, but the jig is a hell of lot easier, at least for me, then screwing around with the dowels.

Let me know if that idea works for your situation.

viewtopic.php?f=27&t=30690&p=221678&hil ... ed#p221678

Gary

[LittleGreyMan]

BUT they will have the actuate size of material.

No Gary. The dowel method does not require this. Read again Michael post in the thread you mentioned. The precision required for setting x y zeros only depends of the oversize of the raw material. The alignment error only depends on the machine precision.

If I understand correctly your jig method, you need a squared raw material and precisely setting the center. So the alignment error depends of the precision of the x y zeros setting.

Maybe I misunderstood your method, could you take some picture while you are machining a double sided project?

I sometimes used jigs instead of dowels, but I prefer using dowels each time it's possible. So, I'm just curious of your method.

[mfirlott]

Thanks for the input.

I have used a jig and I’ve used the 3 dowel holes for alignment on separate jobs. Doing Tiling or 2-sided on a single piece is not the problem however.

The issue is when I try to combine both methods in one job. Tiled AND 2-sided at the same time.

When I set up to tile T1, I cut an extra hole into T2 so that I can pull the piece down the table and align for T2. But when on T1 and I cut the 3 2-sided alignment holes, HOW can I reach T2 to drill those 3 holes when they are out of reach of my gantry.

Thanks everyone.

[garylmast]

I guess the way I was explaining wasn't clear. I reread what Michael's posted and now see he misunderstood me:

By thinking you need to reset the XY datum position, this invites Trouble! That position should not be changed. If you do, then that will almost guarantee a misalignment.

Keep the datum position the same at all times - do not change it. Using the dowel method will always yield perfect alignment as long as you don’t defeat this alignment by changing the XY datum location.

I set the datum at the center location only. I do not change the location once set. Because I was getting misalignment on the back side, I credited it to having a different size material then what I setup in Aspire. I also setup in Aspire as being in the center. When I was using the dowel method, I was getting misalignment constantly. When I turn the material, the center of the material will be in the same position. The gig is used as the alignment gauge and is as simple as shooting some pieces of scrap to the spoilboard. I guess the misalignment problem could of been from something else, but using a jig is faster and did solve my problems.

When Mitch mentioned he was having trouble with the dowels on the tiled portion of the material, simply sliding the material down a jig seemed to make a more sense, at least for me. Again, XY datum position never changes.

[sseale]

Mitch, I have never done tiling but thinking this through with tiling and 2-sided dowel method it seems the maximum spacing between your dowels (in the direction of tile moves) can be half the overall gantry travel distance. This way you always have dowels accurately positioned at the extents for each individual tile move. Drawback obviously would be more tiles required for the overall job.
Scott

[mfirlott]

LOL...my head hurts.

I will try to pen and paper scratch some of these ideas out and see what helps.

I’m sure it’s easier than it looks. Just a lot to think about.

Just don’t want to waste another 10 feet of 3/4 inch walnut again. Well I shouldn’t say waste because after much sanding, I saved the last walking stick somewhat by sanding off the out of alignment edges.

Thanks everyone for jumping in.

[mfirlott]

If anyone has an interest...I figured it out.

Works best if do 2-sided machining first on Tile 1, sides A then B...then I slide the piece down for Tile 2, sides A then B.

I use 5 dowel holes in total. 2 dowels for tiling alignment and 3 dowels for 2-sided machining.

Works really well.


Here are some photos of a finished staff. Is a single piece of African Mahogany with Maple inlays. Cutting Board oil is only finish. Put a hiking point on the end.

[mtylerfl]

Outstanding results! Congrats on a job well done!

[scottp55]

Came out BEAUTIFUL Mitch!!
Possibly worth the headaches:)
scott

[martin54]

Looks like it came out very well, thanks for sharing the finished article, helps to round off the post

[mfirlott]

Thanks everyone. Was certainly a joy to figure it out and I'm very satisfied with the results.