[harryn]

It appears that you made your table "exactly" the right size for this project.

[diyengineer]

I set up one of the mold blocks in the CNC machine this morning and the new 1/4" ball nose cutters arrived at 10 am. The Z axis travel is adequate and I have figured out how much cutter length can be outside the collet to not run into any hard limits like end of Z axis verticaltravel. With potential bad weather expected today I decided to wait until tomorrow to cut the first mold.

There is a very small gap under the lowest stationary part of the Z axis to the MDF block that just seven sheets of stacked printer paper will pass through without snagging. I hope the block doesn't grow any during cutting.

Under my big machine i only have 1.5" of total z height. That picture looks like my machine on a daily basis lol.

[LouF]

Well I picked up my PC and my PC guy said my power supply was dead so he gave me one on the house. Time for a P box and a Mothers keepsake..


Lou

[CarveOne]

While checking clearances yesterday I could see that the Z axis rail was slightly below the lower bearing block, so I removed the whole assembly and ground it flush with the bearing block in order to get this little bit of clearance. I never expected to stack three layers of 3/4" material on this machine. The Z axis of this machine is considerably better (stiffer) than the one on my big machine with 6" of clearance to the table top.

The replacement big machine will be a real honker if I ever get around to building it. Still can't even find time to work on the mini-router I started work on last year.

I started cutting the first mold by 9:15 am today. It will be a 5.5 to 6 hour run. The Precise Bits 1/4" ball nose cutters I got yesterday look like really high quality carbide. It's currently on the third of eight roughing passes. Looks like I could have made each pass a little deeper and eliminated a pass or two. It's cutting at 200 ipm.

Lou, Michael Tyler has a new Tripod Pedestal Table project in todays newsletter. I fell off my tricycle too many times as a kid to want to trust anything with three legs or wheels again.

[CarveOne]

The cut job went well for a total of 5.5 hours. With one exception.

When someone else did the lamination of the MDF layers, not enough epoxy was used, not enough weight was placed on the laminations, and it de-laminated a little when the cutter got down to that level. It's not all that bad, so he is going the repair it tonight so that he can start prepping it for lay-up. Tomorrow morning I'll start cutting the other mold.

I learned a bunch of new things while getting it this far. If we had the RenShape 440 material available it would have gone much better.

The 3D Finish pass with 10% stepover did a smooth job of cleaning up the leading edges from the roughing passes. As smooth as cutting MDF will ever get anyway.

[harryn]

Nice work, especially considering the material. As you know, I am not an MDF proponent.

There are some interesting high density foams that dissipate static which might be better in the future for projects like that. The anti static properties make it a lot easier to control dust and avoid static discharge, which can be really high. (avoids ignition of the dust)

I will see if I can find some suppliers again. I used to use my browser to book mark interesting things, but that turned out to be a bad idea. Now I use a spreadsheet, but it isn't on there yet.

Take care,

Harry

[CarveOne]

I don't like MDF either, but the decision was made for me and all I could do is refuse the job. The RenShape 4xx series materials are just as dusty and bad stuff to breathe also. My dust collection system does a good job of the fine dust but some small flakes/particles do escape during the first roughing pass. I made some removable "fender skirts" that are keeping the particles off of the rails this morning. I have to keep build-up off of the rollers.

[CarveOne]

The second (right side) mold finished with no issues other than the same de-lamination issue as the other mold. This too will be corrected before lay-up begins.

There is the potential for more of this kind of work interfering with my hobby woodcraft efforts.

I celebrated my first molds being completed by ordering the new DeWalt DWP611 precision collet complete set from Precise Bits yesterday.

[cd_edwards]

The second (right side) mold finished with no issues other than the same de-lamination issue as the other mold. This too will be corrected before lay-up begins.

There is the potential for more of this kind of work interfering with my hobby woodcraft efforts.

I celebrated my first molds being completed by ordering the new DeWalt DWP611 precision collet complete set from Precise Bits yesterday.

One thing I did was order extra nuts for each of the collets. I hated removing the collet's from the nuts. So, I have a complete set of collet's and nuts for both a Bosch Colt and my PC690 now. Anyone looking for a Precisebit's collet set for cheap?? :idea: Don't need them anymore.

[LouF]

One thing I did was order extra nuts for each of the collets. I hated removing the collet's from the nuts. So, I have a complete set of collet's and nuts for both a Bosch Colt and my PC690 now. Anyone looking for a Precisebit's collet set for cheap?? :idea: Don't need them anymore.

I am not sure but are the collet's for the colt the same as the ones that fit the Hitachi M 12VC?


Lou

[LouF]

The second (right side) mold finished with no issues other than the same de-lamination issue as the other mold. This too will be corrected before lay-up begins.

There is the potential for more of this kind of work interfering with my hobby woodcraft efforts.

I celebrated my first molds being completed by ordering the new DeWalt DWP611 precision collet complete set from Precise Bits yesterday.

I don't want to seem like a Homer but what is the mold(s) for?


Lou

[cd_edwards]

I am not sure but are the collet's for the colt the same as the ones that fit the Hitachi M 12VC?


Lou

If you check the precisebits site, I think that you'll find that they are not the same. Each router uses somewhat differant style.

[CarveOne]

I am not sure but are the collet's for the colt the same as the ones that fit the Hitachi M 12VC?

Lou

The Colt collet set also work with the Rigid 2400 family of routers.

The Hitachi M12VC/KM12 collet set also works with the Bosch 1600.

The Dewalt 611 collet set also works with the Porter Cable 450.

[CarveOne]

I don't want to seem like a Homer but what is the mold(s) for?

Lou

The molds will be used to make fiberglass/epoxy "skins" that will used to make left and right horizontal stabilator parts for an R/C model airplane. Each half is 22-1/2" long after trimming it to length. Wood, carbon fiber cloth, and Depron foam sheet materials will become internal ribs and spar structures for lightness and strength. The tapered airfoil is symetrical in every way, but is not the standard symetrical airfoil used on many other R/C models.

With just these two molds the two top and two bottom skins needed to construct the two parts can be made. We are using MDF due to low cost, and I already had the MDF on hand. The MDF molds will cause the builder (not me) a lot more manual effort than the RenShape material would be.

Below is a photo of the fender skirts I mentioned. They just sit on the spoil board next to the bearing carriages and the cardboard box material hangs out over the rails enough to keep flying particles off of the top edge of the rails where they get crushed onto the ball bearings. I keep the rails as clean as possible during cutting jobs. The cardboard is low enough that the bottom of the Z axis can pass over it without conflict when needed.

[LouF]

C1 thanks.

[ger21]

Epoxy is not a good choice for laminating mdf, unless you first put on a "sealer" coat, and wait til it starts to gel, then apply a thickened coat for the actual bonding. Otherwise, most of it will soak in and you'll get a poor bond.
I'd recommend plastic resin glue, but it needs to be 70° to cure. If you go the plastic resin route, mix it in a small bucket with a paint mixer in a drill. It's a pita to mix by hand.

[CarveOne]

Epoxy is not a good choice for laminating mdf, unless you first put on a "sealer" coat, and wait til it starts to gel, then apply a thickened coat for the actual bonding. Otherwise, most of it will soak in and you'll get a poor bond.
I'd recommend plastic resin glue, but it needs to be 70° to cure. If you go the plastic resin route, mix it in a small bucket with a paint mixer in a drill. It's a pita to mix by hand.

True. A number of things happened that made this de-laminating worse. The epoxy was applied to just one side of the joints instead of both sides, and then the three pieces were clamped around the edges with not enough weight sitting on the center of the stackup. He was trying to save on the epoxy costs since these are throw-away molds after the stabilators are constructed. We think the center of the laminations were possibly bowed upward by some small amount and the epoxy did not actually flow to the dry side of the joint. He has not tried this before.

Live and learn. I just assumed that he would at least brush or squeege the epoxy on both sides of each joint. I'll tell him about the sealer coat idea. He already does that for the first coat of epoxy when doing lay-ups.

4" solid concrete blocks make good low cost weights for keeping wood materials flat and for glue jobs like this. I have considered building a 4' long removable bridge for my 4' x 8' work tables that clamp to the 2x4 structure under the edges of the table top and has the ability to use a bottle jack sitting on top of the laminated material to push up against the bridge. The bridge would be a piece of 3" x 3" x 1/4" steel box tube. That should generate more clamping pressure than a couple or three concrete blocks. A spreader block of wood might be placed under the bottle jack also. It works similar to the screw jack seen in photos of the old printing presses. My idea is a larger version of a cast iron clamp that I have seen at woodworking outlets that bolts to bench tops.

[CarveOne]

This is the largest sign I've made so far. It's for a residential driveway at a friend's new property. It's 2' x 3' x 1-1/2" and made of two layers of 3/4" thick 1x12 and 1x3 red oak lumber from Lowes. It's laminated so that all joints overlap by the width of the 1x3 board. I used West Systems slow cure laminating epoxy to glue it up. The finish is Cabot marine spar varnish brushed on with foam brushes. Minwax gloss black oil based enamel was used in the cuts. This is just about the maximum working length of my smaller CNC machine.

Caravanserai is the name of a song by Loreena McKinnitt. It can be found on YouTube. Most of her music can be found full length there.

[LouF]

Looks good C1 thanks for sharing..


Lou

[CarveOne]

Thanks Lou. Much appreciated. The new owner gave permission to post it.