As simple as that! …
@tapper No formal meeting or clean up day is required. @Cutter_Roberts and I cleaned and organized everything today. HUGE THANKS for stepping up and helping out!
All items requested by the fire Marshall have been sourced and by tomorrow morning all will be addressed except for the upgrade to our dust collection system.
I have already identified a 10hp industrial system that can be put inside the shop. I was ready to pull the trigger last week, but I was told by you to wait because you are discussing an exterior collector option with the landlord.
The issue is still people cleaning after themselves EVERY TIME they use a tool. I will put a new dust collection system proposal on the agenda for Friday. I am also working on daily, weekly, and monthly checklists that I will post/share so that we can ALL contribute and be aware of what needs to be done around the shop.
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from: Mathew Busby obfuscatedemailaddress
to: [email protected]
date: Thu, Mar 10, 2016 at 2:44 PM
subject: Dust Collector Options
mailed-by: dallasmakerspace.orgHere’s the options I’ve pulled together. This is by no means a comprehensive list of all potential options, but is sufficient for budgeting. Oneida, Donaldson, and Stiles (Belfab collector unit) all provide design services with the purchase of the unit. The Stiles quote includes ducting, but I don’t think the decision will be affected by that, as the ducting cost will be similar for all options.
Stiles/Belfab 4600cfm/8"WC 10 HP $11927
Donaldson 4800cfm/8"WC 15 HP $11307
Oneida 3500cfm/3"WC 10 HP $7550The Belfab and Donaldson units can probably handle the entire shop (3800 cfm demand) and allow us to dedicate the Oneida to the CNC. Stiles’ original quote reflected this configuration with 100% replacement of the ductwork. We will likely be able to reuse chunks of the existing and surplus duct work in the new system.
Belfab and Donaldson units use filter bags that are standard, widely available, and cheap. 28 bags for the Donaldson (complete replacement, done every few years), cost $36.25 each ($1015; price from Donaldson, we can probably use generic bags for cheaper). The Oneida unit uses 3 stacked cartridge filters mounted on a plenum. Each complete filter replacement on the Oneida will cost $1221 (non-HEPA)/$1710 (HEPA). We are blowing the gaskets out regularly on our current Oneida setup. This would very likely decrease with an additional unit, but I would estimate it will still happen. Filter bags are more resistant to dust impregnation. I think HEPA filtration is futile in a woodshop.
The quoted Stiles duct work is the clamp type, which is more expensive that the rivet/screw type currently installed in the shop. Duct work should cost between $3000 and $6000.
An additional electrical drop, based on recent metal shop costs, is expected to be $3000 and assumes we have sufficient capacity at the subpanel.
We’re looking at: $12000 (collector) + $5000 (duct) + $3000 (electrical) + 10% contingency = $22000 for a budget number.
The collector demand outlined above then was before we had the 20" planer (1000 cfm per Powermatic) and several other tools. By my back of napkin estimate, we are now around 6500 cfm, in excess of 5000 cfm threshold for indoor noncontained systems.
A non-marginal part of the problem is people simply not turning on the collector(s) and opening the gate. There is technology available to prevent this (https://www.ecogate.com/ , credit to @AlexRhodes). The cool thing about a PLC running the dust collector and gates is that it can control a VFD to provide an appropriate amount of fan power based on demand – providing some energy savings (to clarify: energy savings isn’t a concern in this matter IMHO). This would also help to control noise. Most of the noise in a dust collection system is from the actually air and particulates moving, not a motor. The flow in a collector duct should be around 4000 fpm, the higher this velocity the louder it is.
We need to quit farting around with dust collection band aids and spend money on an expandable system we can take with us and upgrade as necessary when the collector demand grows. DIY is no longer an option.
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If this is off-topic, i.e. should wait for fuller discussion n D/C option, please ignore for now.
One thing we need to consider is how many dust ports can be open on a given unit before effective CFM at one of the machine ports drops below its recommended rating. The drop-off is non-linear, e.g. a D/C unit rated at 2000 CFM at unit itself looses some effective CFM by time it is measured at machines dust port, so say 1900 CFM when blast gate is opened. When 2nd blast gate is opened on same bus, the effective CFM is not 1/2 of initial effective CFM, i.e 950 CFM, but somewhat less…probably less than 900CFM. The third blast gate probably drop effective CFM at each of the three ports to ~500 CFM, which is well under what most our large tools require. For example Laguna rates large band-saw @ 100CFM, Powermatic rates jointer at 800 CFM, etc.
So we need to take into account, if not already, how many ports can be open on a given system before it becomes ineffective and mange concurrent tool use to that number.
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Has anyone went and talk to cabinet building shops where they would have
this problem?
You’re correct, you described the actual process for fluid pumping system design. This is a fluid pumping system. Any professionally designed system will account for losses in the duct system. If you notice above, the Oneida unit CFM is reported at 2" WC. The other units are rated at 8" WC. The “inches of water column” is a measure of resistance in the system, i.e. the system head. For more than you probably want to know: https://www.engineeringtoolbox.com/pump-system-curves-d_635.html
We don’t have a predictable operation like a traditional woodshop. We don’t pay 8 guys on 2 shift to run 2 table saws, 2 jointers, 2 planers, and 2 shapers. The problem that presents is that the system must be designed for the worst case scenario… every gate open. If you opt for a PLC-based system with VFD on the fan, the PLC will dial the fan back (or up!) to maintain appropriate flow in the system realtime.
edited for clarity
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They have the power to fire people who do not clean up after themselves.
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Glad to hear y’all made serious progress today.
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