Dust Collection - the final answer
There has been a lot of discussion about this topic on other threads but I thought I would start a new one to share my experiences and opinion. After much experimentation, I have come to the conclusion that this, or something similar to this, is the final answer on the topic.
Don't waste your time and money building a downdraft table. This method is extremely inefficient, especially when carving wide boards.
Adding a blower to the carving head to blow away the dust will not help, it will only blow dust around the inside of your machine so that it will get into every nook and cranny.
The only solution that really works is to collect the dust at the source. I have seen at least three methods posted here that attempt to do just that. Ask Bud has plans for sale here to make your own dust collector but it is hard to tell from the photo on the site exactly what the setup looks like. Ringneck Blues has come up with a metal unit and another member (sorry, forgot the name) demonstrated in a video how he adapted a floor sweeping attachment to his machine.
The method I have come up with is similar in concept but I have refined it a little to make it easy for anyone to make with their basic shop tools and the configuration has been tweaked so that you can expect almost 100% dust collection efficiency. After 30 hours of carving, I took the machine apart to inspect it for dust and found it to be virtually as clean as it was before I began the carves.
The secret is in the venturi shape of the opening as well as the ability to get as close to the carving bit as possible without interfering with the Z-truck. The gentle curve of the intake to the plenum ensures a smooth airflow.
I made this unit from 1/2" wood on the sides and back and 1/4" ply as a covering. The 90 degree angle tube to connect to the dust collector was bought for around six bucks and is secured to the dust collector using T-bolts inside to provide secure bolting. You will notice two threaded holes on the shelf of your CarveWright unit. These are used to secure the collector to the machine using two small angle brackets mounted to the side of the unit.
Hopefully you can duplicate the setup from these photos. It is important to note the airfoil shape of the intake. This is necessary to provide an airflow that will pick up dust from the sides and to avoid vortexes that will occur with sharp edged intakes.
You can make this unit in a couple of evenings and if you do you will never have to worry about dust again. The interior of the machine is completely free from dust after many hours of carving. I did not even notice any dusting on the clear cover. I can't imagine anything that would work better and so for me, this is the final answer.
This would be a simple item for someone to manufacture out of some sort of resin and hopefully LHR or someone will offer it and a replacement cover with the clearance section cut out for a very reasonable price. Dust is more than an annoyance, it is a health hazard and a guaranteed path to reducing the life of your machine and creating all sorts of operational problems. A dust collection system like this should have come as a standard accessory with the sale of every machine. If it had, IMHO, many of the problems experienced by the users would not have occurred.
Reply With Quote