Buddy BT48 Alpha table MKIII

[Ajcoholic]

Well, the UPS man just dropped off my box of Festool 50mm vacuum hose.

I certainly hope that the hose will withstand the vac, it is much more substantial than the shopvac hose.

I will cut the hose and install it tomorrow, and give it a test run!

I already have a test file to cut - a 1/2 sheet of 12mm Baltic birch, that I cut out three sets of parts for one of my children's step stools. But this time no tabs

More feedback tomorrow! If it works, I can call the installation a success and finished. If it doesn't, well not sure what the next step is in terms of hose... but I'm going to be positive and figure the German's know how to make a decent vacuum hose

[Ajcoholic]

OK, after a few more hours of fooling with the hose(s) I finally have gotten it beat.

I had ordered the 50mm Festool vacuum hose - the silver "non conductive" one - since it is much cheaper in proce than the green anti-static, conductive version.

I have two Festool vacuums with the boom arm support, in my shop. The boom arm requires a length of 50mm AS hose (which comes with the package) and based on the strength of that hose, I knew it would do the trick in my vac hold down setup.

I assumed that the non AS version of the hose would be the same hose without the carbon in the rubber, but the same strength. Not so... the hose is actually quite a bit softer feeling. I cut two pcs and put it into the setup, but when I turned on the regen blower and started moving the table around, the hoses started to pinch where they did the 180 bend.

So, I "stole" the AS hoses from my boom arms, and placed those in the CNC vac setup. They worked great! No tendency to fold at all.

I used the non AS hose in my boom arms, and just jumpered the connectors with a length of wire to keep my Festool sanders static free.

The price of the Festool hose here in Canada is $224 for 13' of the AS hose, and $139 for 13' of the non AS hose.

Here are the hoses installed:

[Ajcoholic]

The first thing I tried to cut was three of my kids step stools. The parts need a full 1/2 sheet (48" by 48") of 12mm Baltic birch. I cut almost all the way through, and then did a 2nd pass to cut though. I also tried a few of the side pcs a full through cut in one pass.

Not wanting to cut into my spoilboard that was glued onto my plenum, I placed an un-cut sheet of 1/4" MDF between the BB and the spoil board. It was still holding down pretty good.

I cut the parts out just fine. Just one of the narrow pcs came loose from the vac but the sheet was kind of curled up at that corner so I expected it.

Over all, I was very impressed with the strength of the hold down and how it performed.

I also am doing a run of craved chair seats for some kitchen chairs. I had to cut the pattern out of 1/2" ply to make sure the outline would fit. I just placed the ply blank on a pc of 1/4" MDF again, and placed it on the spoilboard (without covering up any of the open sections - that typically would leak too much air through). Again, no prob, nothing moved and I did a full cut through in one pass...

[Ajcoholic]

So, I guess this ends this chapter of my Buddy - the upgrade first to the all-aluminum table, then implementing the universal vacuum hold down.

Was not without a little head scratching and the odd doubt that this would be worth it... but, after what I have done so far I think it will make an already very functional and useable machine that much more. I have some melamine cabinets to make next week - to further test and fine tune my new edge bander, and also to test run the CPP & the vacuum table - and some new router bits etc.

[Ajcoholic]

One final note - now that I can run the regen blower with the release valves 100% closed, the noise is very reasonable. It is still actually less volume than my central dust collector.

And, with the spoil board fully covered with the uncut sheet - you can feel the air rushing into the filter attached to the vacuum booster - but there is no squealing, as many have said occurs with the simpler vacuum relief valves.

[Simops]

Well done and dusted Andrew. It helps to have a 10Hp blower....and 3 phase power...... oodles of grunt!!

Look forward to completing my attempt at some stage soon.....I can only have single phase and 2Hp so I'm not very optimistic of the same holding power.....will give it a try and see......may have to add a second blower......

Cheers

[Ajcoholic]

Well done and dusted Andrew. It helps to have a 10Hp blower....and 3 phase power...... oodles of grunt!!

Look forward to completing my attempt at some stage soon.....I can only have single phase and 2Hp so I'm not very optimistic of the same holding power.....will give it a try and see......may have to add a second blower......

Cheers

Yes Mike getting that 10 hp blower used from the for sale on this site was a blessing. I think the German made unit will last my lifetime and then some, and was still (after freight) 1/2 the cost or less than the Chinese Fuji 20hp unit I was looking to buy.

As with most things mechanical, there is no replacement for horsepower!

[Ajcoholic]

Sorry, I meant the Fuji 10 HP (not 20) that I was looking at.

Today I had to machine some dining chair seats. The plenum/spoilboard is easily taken off the deck on my Buddy. Just loosen the 4 Incra clamps, and lift it off. I can easily do it without help.



Then I can use the T slot/clamps to fixture my furniture parts that I dont want to hold down with the vacuum.

I can switch back to vacuum within minutes.

I just made a few wooden plugs to put in the PVC pipe entry holes... with a steel washer, so I can use a magnet to lift them back up when I want to put the plenum back on.

Andrew

[Ajcoholic]

A small update - regarding my linear rail side bearings (that support the side of the new table).

I noticed that the aluminum angle that holds the front bearing blocks to the side of the Buddy chassis was slightly flexing inwards. I also started to hear a little popping noise hear and there while machining.

I had ordered some more bearing blocks (they are not expensive) and just a few days ago, one of the bearings parted ways with a few of the ball bearings.

I believe that there was a little extra stress from the rails not being 100% parallel - I'm only talking maybe 1/32" or so but they have no play what so ever. So, I will be redesigning the mounts, so they will be able to flex somewhat side to side - but still hold the bearing blocks at the right height.

I will mount the bearings on a length of 1/8" plate aluminum that will be spaced out 1/8" from the Buddy chassis. Then, bolt the plate to the Buddy chassis above the bearings by a few inches. Then the aluminum plate can flex in or out as the rails travel back and forth. Hopefully eliminating the issue of undue stress on the bearings themselves.

I thought as well, the aluminum table might expand and contract in length through the seasonal change in temperatures (from about 60 degrees F in winter to upwards of 85 F in the summer) and the flexible plates will also allow for this.

Hope to change the bearing tomorrow - the replacements came in today. I have more work to do on the router so I need to get this fixed immediately.

Good or bad, I will report here to help anyone trying to do something similar.

I am confident that this will fix the issue. I might end up placing two bearings side by side (8 total) to halve the load on each bearing. These 16mm bearing blocks are available shipped from China, for just over $20 US from some sellers... I ordered a second set for spares as well.

[gc3]

ominous to have a bearing failure so soon...did you see this flex on both sides? to fab a flexible linear rail system seems to be going in the wrong direction to me...did you check table rail run out with a dial indicator? why not shim bearing blocks to parallel? might be a combination of all the factors...table expansion spoil board movement cutting forces vacuum ect ect...this design looks difficult to keep rails bearing block clean of dust/debris...keep the rails clean and lubed bearing blocks can get filled with fine dust easily causing issues... this has to be the first router I have heard of with a flexible rail system...good luck