Fein TIII and the BradyVacII

[adana]

Hi all,

I've finally decided to join the rest of the world and put together a working vacuum holddown setup. I've reviewed the BradyVacII system - and I think I mostly understand it - and I've purchased a Fein Turbo III.

So... some questions that have occurred to me so far:

Fein TIII specific:
-I've read about these things overheating. What do I need to do to ensure mine doesn't?
-There's a pair of buttons labeled "motor control" and +/- respectively. The included documentation had no mention of those. I've just left them alone so far... any recommendations?


BradyVacII specific:
-what's the recommended cut depth, up from the bottom, for the distribution plenum?
-is it possible to make a general purpose BVII puck that's just a big spoilboard, with no part-specific cuts in the top? For such a use would you cut the underside much deeper to encourage even more air flow?
-does the type of bit used for surfacing the top influence the amount of air the spoilboard can pass? My bit (Amana RC-2250) leaves a semi-glazed surface, which seems bad.

Thanks for any insights or links to other threads! I know there's a ton of this stuff already laid out, I just wasn't able to find the nitty/gritty.

Adan

[harryball]

All you can really do is make sure they have good airflow around them. Don't close them up in a box and run them. Also, and this is open for debate, but leaving a slight leak so some air goes through the vacs is a good idea IMHO. Mine leak around the hose and I did not tape them to seal it completely.

I don't use the Bradyvac design with the grid cut in the back of the spoilboard. The channels in my grid are about 3/8" deep.

/RB

[adana]

Thanks for the reply.

- the Fein is so quiet, I won't be tempted to enclose it. Maybe the quietest tool in the shop!

- is there any one part of the thing that is the canary in the mine? Should the top of the vac, say, be cool to the touch, and if it isn't, crack a little more leak air?

- I was confused by your comment about the BradyVac setup... do you mean you're using an alternative style of spoilboard setup, and the grooves in that are 3/8"? Or do you have a grid of grooves on top of your surface?

Thanks again,

Adan

[harryball]

Some seem to hear a difference in the vacs but I think it's kind of just the way it goes, you can't really do anything about it once it starts. My vacs sit outside in a plastic cabinet right now. I open the cabinet doors when I turn them on for ventilation.

I use a base board followed by a 4 zone grid board with my spoilboard (UL Trupan) glued on top. The grid cut into the 1" thick material is about 3/8" deep. If someone doesn't beat me to pictures I'll try to post a few later today.

/RB

[adana]

That'd be awesome, thanks.

I've been getting by without vac for so long, this is exciting to consider all the improvements that might be opening up for me.

[Brady Watson]

You can go .125 to .1875" deep with a BradyVac removable vacuum grid/plenum setup with the Fein. The key here is that it is removable so that you can also use carpet tape, clamps, screws and any other specialty hold down methods you want without tearing up a traditional ultralight bleeder board - which has low screwholding ability. Add it to the table when you need vacuum - take it off when you don't.

-B

[knight_toolworks]

if you leave the vac as is with the included tank there should be enough leakage to keep it cool. I made a nice sealed box for mine and the heat from the lack of airflow caused them to melt.

[adana]

Thanks for the replies, everyone.

Steve, excellent warning! I'll certainly avoid that approach.

Brady, thanks so much for all the information you've shared in the articles and on the forum. And thanks for the answer here. For sure, I'm embracing the removable aspect of this method. It's those frequent unpredictable (but fun) jobs that have delayed my foray into vacuum.

I started with a 0.3" deep grid underneath... is that bad? What's the downside to a deeper grid underneath? It seems like it might help distribute the airflow better on a larger plate?

Attached is an image of my first BVII setup. It's a test-scale fixture for making some little magnetic wood pieces (0.9" x 1.5"). When I first tested it last night, there was plenty of down force on the individual pieces but not much lateral slip resistance. This is bad both for cut forces as well as for the magnet forces: each piece has a very strong magnet embedded in the wood, and when they're cut free of the stock they'll want to get away from each other.

This morning I spritzed it with Craft Bond and let it dry for a while. It seems to have a good bit more friction now, probably enough. The spray probably also helped seal whatever leakage was occurring in the cutout paths, no? My only concern is that it might come off the Trupan and stick to my workpiece... but that doesn't seem to be happening yet. Have others played with this kind of approach to juice the friction up? Is it a bad idea?

What about those +/- motor control buttons on the Fein? The "more power" impulse in my wants to hammer the + button until it begs for mercy, but that seems unwise in light of the melting vacuum stories.

[curtiss]

For about 10 - 15 dollars you can tap in a fitting and add a simple vacuum gauge to your system someplace.

This is about the only way to really know what your system is doing.

[adana]

Thanks, Curtiss. Is there a make/model gauge that's a favorite with folks here?

My first somewhat-larger-scale BradyVacII puck got its first test run this morning. It's a 15" x 48" system, holding down 18mm baltic birch. It was able to pull a slightly warped piece flat without my having to push it down (even in the 'bad' direction: ends up). And it held the piece during a 0.375" deep single pass of a 3/8" roundover bit, 1/2" center diameter... which had to be a lot of reaction force.

I'm pretty excited about that.

[feinddj]

Adana,

I have a regnerative blower on my table so I can't speak to the bradyvac part.

The motor control is a three position switch that is ON/OFF/AUTO ON. When you plug a sander or whatever into the front plug, the vac will go on and turn off with the tool. the +- is simply the variable speed.


David

[curtiss]

This one looks pretty cool

http://www.ebay.com/itm/NEW-2-52mm-BLUE-DIGITAL-LED-VACUUM-GAUGE-METER-FOR-CAR-MOTOR-TRUCK-/290776454681?pt=Motors_Car_Truck_Parts_Accessories&hash=item43b3a09619&vxp=mtr

lots here
http://www.ebay.com/sch/?_nkw=digital%20vacuum%20gauge&clk_rvr_id=403706010897

[Brady Watson]

Adan,
Looks like you are well on your way - thanks for posting pics. There is certainly nothing wrong with your BV grid being .3" deep. I've gone as shallow as .06" deep while still maintaining performance. The deeper channels *may* aid in additional CFM, but on smaller grids it is a moot point.

When using a BV1, the shallower grid depth gives you more surfacing room on the top side - and as a result it will last longer over time because you can eek out a few more surfacings out of it.

A gauge is a good idea since it will tell you what's going on before you have a failure. You don't need much - you can even thread a nipple right into the Fein hose itself (near where it connects to your table) and then use capillary tube to bring the gauge closer to where you can see it. An automotive type vac gauge works fine...

-B

[adana]

Thanks as always for the help, everyone.

- variable speed, doh! Of course.

- fancy blue-glowing gauge, very nice... good options to consider for sure.

- thanks, Brady. That makes sense. I'll post more pics later. I'm suddenly anxious to retool every single thing I make! This is changing everything.

[curtiss]

Of course, once you get set up with the BradyVacII....

the BradyVacIII will come out.

[Brady Watson]

Of course, once you get set up with the BradyVacII....

the BradyVacIII will come out.

HA!!! :D

Not anytime soon...but 'cha never know :rolleyes:

-B

[adana]

Ha, I'll wait and upgrade when you get to the BradyVac Pentium!

[Brady Watson]

Ha, I'll wait and upgrade when you get to the BradyVac Pentium!

A couple years ago I thought about making an automated vac system where zones would turn on or off depending on tool movement - all controlled by solenoids and a custom post processor. Of course, this would involve well thought out toolpaths in order to make it work without failure. You wouldn't want to shut off a zone that might not seal again if it was turned back on to finish cutting etc.

In the end, K.I.S.S. prevailed as it started to get too complicated. If I was just some dude knocking around on the weekends in my garage it would probably be 'real neat'...but when I have to rely on my setup to make a living, I have little patience for failure due to things being too complicated. Every little thing you add to a robotic system increases the possibility for failure.

-B

[adana]

Yeah... definitely KISS! There's a nice balance of complexity/simplicity to the system as proposed. And most of the complexity is embodied in the materials and tools (Trupan, vac tape, special vac/blower)