Desk top style or cabinet style?

[rusty105]

I am pondering the direction I want to go with my 1st flowbench. I can't decide if I want to build a desk top / table top design, which looks just like a workbench surface, or do I want to build one that looks like a Superflow or Mercdog style of cabinet. I think I am leaning to an orifice style for cost considerations. That is unless someone can steer me to a pitot tube design. Future options include an FP-1.

Can anyone point out some Pros and Cons of each?
Thanks

[Tony]

If you were designing a commercial bench for sale, something small and neat will look a lot more attractive to prospective customers.

For yourself at home, a big boxy bench offers a lot of very practical advantages regarding high air flow capacity, and low internal flow velocities. Large internal flow areas and settling volumes are the easy way to eliminate flow stability problems without a lot of troublesome development work.

A compact table top bench is quite likely going to have very high internal air velocities, lot's of sharp corners, turbulent flow, and a whole lot of potential stability and calibration problems you can well do without, as well as a comparatively restricted maximum airflow.

[rusty105]

I didn't mean to imply table top, as something I could put on top of a table(SF-110), but something that has a large table top for a work surface, and no upright 'back board'(SF-1020). While the back board is great for mounting the manometers, the openness of just having a tabletop could be beneficial in some way I am sure. I guess I am leaning towards something that may be cross between the two, maybe an oversized SF-600, with just a little bigger work surface.

Rusty

[Tony]

Ah, sorry I misunderstood.

Any available extra bench top surface in a lab or workshop can be useful, even when it is not being used as a flow bench. My bench is a big box on wheels with no back board.

My manometers are screwed to the wall close to a window which provides excellent natural lighting.

A few people here have suggested a modular flow bench where the blower, flow measurement system, and work surface are all separate parts. The system is then extremely easy to work on, modify, or upgrade.

For example, a very noisy blower could be located the other side of a wall, or some distance from the actual bench. The work top could be just a heavy steel plate, completely open underneath, which greatly simplifies bolting down various cylinder head adapters.

Dare to be different...

[larrycavan]

[Greg]

Rusty, I made mine as a large flat topped cabinet. The extra area on top gives me space to sit the computer and whatever else I need. I also made it modular inside, so the box with the vacuum motors is easily removed to change a motor or if a better idea comes up in regard to a vacuum source. There are some photos in the .

The extra size also allows for a straight run of air and a big settling plenum.

I'd advise to make something about 1/3 bigger than you ever think you will need at the moment, it always seems that first ideas are a little on the small side.

Another thing worth a look is to set the machine up close to your fuse box, mine is around 20 metres away and 60 amp cabling isn't cheap to run for that distance compared to having the machine sitting next to the board.

[rusty105]

:p
That is one BIG bench, but looks very workable! I am doing this on a budget, so I think I might be leaning towards an oversized SF-600 type, with manometers to start, but like I said earlier, FP1 or some other computer setup is in the future. A couple things, I do like is the laminate. That should help with air leaks. And at a great price as well. What are you using for the wood, is that 3/4 plywood or MDF? And what is the white PVC that looks like it is comming up from the top in one of the pictures? The one with the laptop, and the head on the adapter plate.

[86rocco]

[rusty105]

Anybody have a source for low cost laminate in NY or CT??

[Tony]

The cheaper "flakes of wood" type of particle board can certainly leak a fair bit of air, but the much denser structural MDF is vastly more resistant to leakage.

Anyhow, a good thick application of marine varnish or clear estapol inside, soaks right in, and completely prevents any air leakage through the material. Laminate certainly looks good, but is far from a low cost solution. The thinner laminates used for kitchen shelves and cupboards simply do not have the physical strength to resist air pressure. These kitchen laminates invariably uses the structurally weak "flakes of wood" type particle board under the laminate.

Your best bet may be to build the whole thing out of three quarter, or one inch MDF, and buy a roll of laminate separately. That can then be glued onto the outside at some later time after the bench is completed.

My bench uses one inch MDF bolted to a welded steel angle frame. The bolt heads have been recessed into the MDF, so that later on I can glue on some laminate. Something I have yet to do.

[Shawn]

[gofaster]

Laminate material is also available at Menards, comparable prices. I didn't buy any yet, but I was impressed with the color choices.
My bench is following the MSD or SF-600 style cabinet. It's going slowly, but I have enough done to consider myself locked in on the layout. So far it has been a great (and sometimes humbling) learning experience. One consideration for me is that my shop is small and this design has a small footprint.
Now that it's progressing, I think that a benefit of the wider bench style is that it would be possible to have storage within for periferals like the CPU and motor controller. That would probably save space in the long run over the narrow design that I chose.
I also find myself thinking about the advantages of having the blower unit as a separate entity. In my case, it would have made sense to put the blower upstairs to get away from the heat and noise. Once the current bench project is finished, I may feel compelled to move on to a second flowbench project!

[rusty105]

Tony,
I was thinking of the laminate sheets, or roll to lay over 3/4 MDF, since you mentioned 1" MDF, I think I might try that. The 3/4 was only $23 or so at Home Depot for a 4x8 sheet. I think it was a 4x8. Is the steel frame necessary??

Thanks

[gofaster]

Laminate overlay material is what I was referring to. I have one piece of pre-laminated (white) particle board that will be the back stop, to which i'll mount the inclined manometer, and possibly the flatscreen monitor.

I used 3/4" baltic birch plywood for the cabinet. Used support strips in the corners that I made by ripping 2 x 2's on a 45 degree angle. That gave me something substantial to screw and glue the plywood together with. There were places where the large support strips wouldn't fit, and I substituted thinner strips of hardwood.

I primed and painted the insides of most of the cabinet to seal the wood, and I plan to apply a covering of laminate to the exterior for sealing and to try to end up with a professional looking bench.

[Tony]