Grounding flexible dust collection hose - questions

[bcondon]

So my situation was that I was pouring a foundation for the shopbot room (18 x 24) and a adjoining foundation for the refurb in the house which was
24x50 to contain the shop. The challenge was that I had to run a couple pipes under the corner of the existing garage to get them connected.

The DC is located in a fireproof closet in the shopbot room.

It took me under a day to put in 3 drops around the shopbot room (flexibility because we did not know where the machines would go) and I put in 7 drips in the basement shop. All tools have a dedicated drop with gates and flexible connection.

My cost for gates, pipe, fittings and copper wire were under $200. The S10 control to wirelessly turn on the DC from an location (remember we are physically separated between the basement and the DC) was $50 which includes 2 control locations, FOB key, and the "appliance device - 240 VAC" which actually turns on the DC.

The cost of metal would have been probably $1000 + plus the challenges of getting the angles correct. The fittings in metal are brutally expensive and you need a ton of them.

Brady - if you do a neat job, the wood does not get caught up...

I would also refute the comment that the metal has a better flow over b over PVC. PVC is smooth and you can get street sweeps for elbows giving you better flow there (which is where the losses are)

I could also add separators at the DC and at the Shopbot to get the shavings before they hit the DC.

I will say there are two camps for Metal and PVC. I see a lot of people in the metal side wave their arms and yell fire when actually result, if you take a small amount of care to put in the ground wire and make dedicated connection, are inexpensive and from my mind, I KNOW that I have a good connection.

I have worked as an electrician so I understand grounding and power panels (I have 4 power panels in the house/shop/garage to distribute power).

Funny story with our last house, we had a separated garage with full woodworking shop in the gambrel second floor. I wanted to put a separate 200A panel in the garage (separate service) and I had a 200 A panel in the house. The town said ONLY ONE SERVICE PER PROPERTY so I said ok... we will pull 400 amps through the house... no problem.
The town electrical inspector has a fit and I told him I wanted it to be safe which is why I asked for 2 services... I got two services...

Oh well.

In the end I am very pleased with my setup. It works well, it is safe and I don't communication failures on the shopbot...

My DC is a Reliant 3HP system so it is a bit light for CFM (1250) but takes care of my needs...

Thanks
Bob Condon

[POPS 64]

Hi guys were I live pvc is high in price . When I decided to switch to metal I decided to try something different , I went to the home center bought heating ducts with adjustable elbows and used y's so everything was sweeping. And during and after assembly I double coated every seam and joint with the best seam sealer they had and it works great . The big test was with corian doing lithophanes when I finished the table and floor are as clean as when I started I was shocked . I run the main 3 branches with 4 drops all with blast gates. But for being on a budget I wouldnt replace with the good stuff . All in the sealing . Just do what makes you comfortable with and your budget long as it works and is safe. Good luck Jeff

[Kyle Stapleton]

PVC works fine, but you do have a problem with your setup. It looks like you have just 4" runs from the DC to all your tools which is very bad when it comes to getting the most out of your DC.
What size DC do you have and how large is the intake on it? If the intake is large then 4" you really should rethink you ducting, it may cost more money but it will be worth it. We fitted ours ( home shop) last year from all 4" to 8",7,6,5 and finally 4" at the tools and wow

[aschutsky]

Before designing and running all my DC piping, I did about 2 months of research. As a weekend hobbyist, I was concerned mainly about the most efficient setup (while remaining safe of course) I could build for the dollar. My budget was 500-600 including the dust foot. I went slightly over but not much.

My cheapo setup includes:

-About 30 feet of 4" PVC plumbing along with 7 blast gates
-Harbor freight "2HP" blower motor
-DIY Phil Thien baffle in metal trash can
-Filter delete and venting excess dust into woods through window
-Connection to CNC, floor sweep, 2 roaming 4" pickup tools, connection to radial arm saw
-2 x 10' flex hose for roaming pickup tools, 1 x 20' flex hose for CNC

My setup works quite well for my little part time shop. If I were running a full time shop, I'd for sure invest in 6" + metal piping and a much larger blower. I spent a TON of time reading about 'grounding' of the PVC setup. I could not find any instance where a dust collection system using PVC piping was definitively tied to a fire or explosion. I came across this interesting article through a recommendation which applies some physics to the subject:

https://home.comcast.net/~rodec/wood.../DC_myths.html

With that said, it's SO easy and inexpensive to run a grounding wire either through or around the piping (or both) to eliminate any threat of shock or issues with coms on the bot. I'm more concerned with the com issues than anything else at this point.

Back to the original topic - I had been playing around with my PC and I'm fairly confident this is more PC related than anything. My previous laptop had no issues with com loss, so I'll try another PC this weekend to see what's up before running all the grounding wire - which I'll do anyway but I want to find the root cause here.

[aschutsky]

Update: I've grounded everything now but also trying a new PC for the bot (laptop). Com efficiency has moved to 88% or so and NO issues running a few projects through it.