WoodShop Committee Meeting Tuesday Jan 5 7pm

Woodshop
#6

Assuming there isn’t some pressing need I’m wholly unaware of, I think the dust collection system is the biggest deficiency in the shop. I would advocate a separate dust collector for the CNC router to match the MultiCam spec. Then repiping (as necessary) and upgrading the dust collector. From the problems people have been describing (and I’ve witnessed), I think too much refuse is making it to the final filter. This is likely an indicator of insufficient particulate removal at the cyclone.

If the cyclone is operating within its design parameters (I believe it is not), the the final filter simply can’t handle the volume of particulates it is hit with, ergo undersized.

3 Likes
#7

Maybe a smaller collector for special materials on the cnc? I’d second dust collection though

1 Like
#8

Yes, I think a separate collector is necessary for the CNC only.I don’t think a special material collector is necessary, but certainly a dedicated one for the CNC. It should be part of the cheat sheet: before and after, empty the dust collector. It isn’t about cleaning up after somebody else… it is about maximizing performance for YOUR cuts.

On a side note, it says in the MultiCam manual to lower the dust boot such that the springs are half compressed at full cut depth. I hadn’t read that until today. It would help drastically if people would just lower the boot enough to cover the tool.

#9

You guys should all come to the wood shop meeting.

@jast, @tapper (thanks for taking that on) found a crack in the dust collector on the back side of arm of the dust collector and has replaced that part, so while the dust collector is working better than it has in the past, it is past ability in my opinion. The collector is rated for 1-2 tools at a time and the wood shop is so heavily utilized, it is definitely time for a re org and another collector. As for another drum. I think one is still needed, but not a priority.

@MathewBusby The crack had A LOT to do with the second filter getting filled up. I have looked at other dust collectors and will present some stuff tomorrow. One of the biggest things I notice is that people don’t turn on the dust collection or open the gate or close it when they are done. I am guilty of this, as I have gotten lost in a project. So I have priced out what it would take to do our shop (minus a second collector) on automatic collection and blast gates through http://ivacswitch.com/ and will present it tomorrow.

4 Likes
#10

The key is the name of the thing: “pressure foot”. It serves two purposes: support for the vacuum and hold down the material.

From the User Manual…

The Pressure Foot can be used for both removing waste during the cutting operation and applying pressure to the surface of the material to reduce vibration and keep parts from moving. Its innovative design applies adjustable spring pressure, which makes the Pressure Foot an ideal option for cutting paper-masked plastics and acrylic materials. Equipped with a standard 2” hose input, the Pressure Foot is typically used with a high pressure vacuum and can lift with the spindle to avoid hitting clamps or other obstructions.

In my experience, correctly adjusting the pressure foot makes a noticeable difference in both dust collection and cut quality.

Make absolutely certain the pressure foot moves freely! Debris / sawdust sometimes collects between the spindle collar and the pressure foot which interferes with movement.

Make absolutely certain the pressure foot will not “bottom out”! I have no idea what would happen but I imagine it would be undesirable. The pressure foot should “float” along the top of the material.

Be careful using it when cutting three dimensional pieces! I imagine the pressure foot will break off anything it hits from the side.

2 Likes
#11

I always run the boot within what I now know to be the design parameters and don’t experience the problems many do. I also think some of the tooling is operated at such conservative rates that dust removal isn’t as effective as it should be. Everything should be making chips not dust. This is off-topic now, sorry everyone.

1 Like
#12

Item needed for safety
more mats. one in front of each tool.
maybe it is my shoes, but with the sawdust and stained concrete floors, I slide way too much. the table saws could also use mats on the left hand side as you push material thru.

Item wanted

  1. Vacuum chuck for at least one lathe
    Allows quick and easy re-positioning of objects.
    expands forms you can hold.
    Fred’s place still has a few pressure gauges and filters. Lots of vacuum pumps, but those are monsters.
    different face plates are easy to construct
  2. storage for jigs
    Shame when they get tossed because of clutter.
    laying the sleds on the scraps isn’t great.
2 Likes
#13

Wanted:
Communications channel
I am fine with Talk, Hangouts, Email, whatever. Woodshop is one one of the most utilized dept in the Space, right up there with 3D printing. We have a lot of people, but little communication.

This meeting is great and will enhance that. We do need something in between meetings. People use the woodshop at all hours, so in-person suffers a lot of lost info.

For example, I didn’t know about a grant. that is fantastic. what is it for? restrictions? how much?

Communications also helps when we get stuck on a project. Like, how best to handle breadboard ends?
Or to brag about a tool, like the Domino. or the Tracksaw. i was so happy to discover them at the perfect time.

1 Like
#14

Showcasing
Creative Arts is doing great work highlighting our artists and work.

Woodshop can do the same. We have so many talented individuals. I want to see what everyone has done.

1 Like
#15

That. Exactly.

(satiate the Discourse beast)

1 Like
#16

Fixtures? is that the best word?
*The Miter Saw needs wings to support material and end stops. I believe there is a plan for this, but I do not know what it is.

I would like to help.

*Lathe stands
the new lathes need stands.

Safety:
The jet 1360 slides on the floor. it needs a nonslip, beefier base.

I would like to help with the construction of the needed needed items. If we have a design plan, I’ll put it together or help someone else.

#18

I agree that a separate collector for the CNC would go a long way towards helping the situation. I don’t believe that, at present, we need to replace the Oneida dust collector. I rebuilt it a few weeks ago, and had the chance to play with it using the new pressure guage, and I believe for most of our tools, it is adequate for the job. But not the CNC.

The problem with the CNC is two-fold - First, the router is placed at the long end of the shop, where vacuum pressure is lowest, and the boot is typically improperly adjusted.

But I believe the biggest problem is the huge amounts of dust created by people cutting MDF (and wood to a lesser extent) with incorrect feedrates on their bits, producing huge volumes of flour-fine dust, that promptly choke out all the filters in the shop, including the dust collector filter. It really only takes one medium sized job on the router like this, to wipe out the roof HVAC filter, the two ceiling filters, and the big $400 filter on the Oneida. This ultra-fine dust, not wood chips, is doing us in and costing a lot of money in filters and repairs.

With respect to the Oneida, the condition of the filter is directly proportional to the airflow it can generate in the dust collection system. It performs pretty well at outflow pressures less than 3psi, but once past that, flows drop off pretty rapidly, and at 5psi, the dust becomes so embedded in the filter media, that it gets ruined in short order, and blowing it out won’t restore the system pressure anymore. If you leave it running at that pressure, the seals (made of neoprene rubber weatherstripping), get blown out (as they are now) and vacuum pressure goes to hell in a hurry. It’s been a long time since most of us have seen that collector running at less than 5psi. One bad MDF job and it’s toast.

So, my proposed solution would be:

  1. Implement training necessary to stop the MDF dust clouds, and stop people who are producing them, further assist them in getting their feedrates right, before they are allowed to resume. MDF produces little dust when you cut it correctly, period.

  2. Implement a routine maintenance program to perform regular maintenance in the entire shop, but especially the dust collectors. This activity translates directly to money. The more and better maintenance that gets done, the less we have to spend on filters and fixes. How to do this is the trick, but it must be done.

  3. Implement a standalone collector for the CNC, and modify the ductwork to improve efficiency through the rest of the shop. We have a couple of engineers working in the woodshop, that would probably be happy to do the design work for this.

  4. The automatic blast gates look pretty good, I wonder if the controllers could be integrated with the rfid access plans?

4 Likes
#19

Just wanted to give @Tapper a quick “thank you” for the work he’s done on the dust collector recently. It certainly feels “whack a mole” recently with the various problems and he’s been in almost constant contact with Oneida while fixing various issues.

When you mention feeds and speeds in relation to MDF, do you think faster feeds create less fine dust? I cut some recently and had the foot extremely low and was using a downcut endmill. It was so low I had to think about pockets I was creating and potential collision with plastic ring on the side of pocket walls. The dust collector caught almost all of it, which helps HVAC and air filters. I have no idea what the particle size going to the dust collector looked like though.

3 Likes
#20

Kent,

This is all about the chipload you are cutting. Every CNC bit has a certain designed chipload value at which it runs best. Staying within the design range is hugely important to the job setup. If you go beneath the design range, you’ll start making dust instead of chips, heat the hell out of the tool (and dull it quickly, or break it). If you push the tool too fast, you’ll get chatter, some dust, and even more tool killing heat. Most broken bits are caused by heat, not the pressure of the bit against the stock (which is what most people assume, and why they chronically want to overdo it when slowing down the tool).

Basically, all chipload means is “the length of a chip cut in one revolution of the bit, by one flute, in inches”.

Another way to say it is, “This bit should be cutting chips “chipload” inches long, if I set up my feed and speed correctly”.

Lets say you are using a 1/4" upcut 2 flute bit in hardwood. Your chips should be somewhere between .005-.007 inches long. Knowing that, here’s the simple math to calculate the feeds and speeds:

Chip load = Feed rate / (RPM * # of Cutting Edges)
Feed rate = RPM * Cutting Edges * Chip load
RPM = Feed rate / (# of cutting edges * Chip load)

Most often, I see vendors recommending an RPM on the packaging. For example, the 1/8" compression bit I bought from Amana, said to run it at 20,000 RPM on the packaging. The chipload for that bit is .002-.004 inches, so my feedrate would be:

20,000 * 2 * .002 <= feedrate <= 20,000 *2 * .004, or a speed of 80ipm to 160ipm. So the first time I used the bit, I would setup my toolpath to run at 80ipm, then use the fob to adjust upward until I get nice looking chips at runtime. Next time, I’d just program in whatever worked the last time I used the bit.

Onsrud publishes a great reference on the chiploads for their bits, and you can usually apply them to other manufacturers bits for a given design without too much trouble:

https://www.onsrud.com/xdoc/feedspeeds

5 Likes
Help: Feed and speed rates to cut plywood
#21

We probably need to create a tool section just for MDF then.

I wish VCarve had a better way to handle all of it. FeatureCAM (what we use for Haas) let’s you select material and calculates feeds and speeds based upon that.

4 Likes
#22

Put maintenance (a chore list) on the DMS schedule. Hopefully that will draw in folks who are not regularly at DMS but are willing to lend a hand.

#23

Probably, but the problem is, that chipload provides a starting point, But users need to know how to deal with variation from the baseline, for things like dull bits, harder than normal stock, softer stock, high humidity, etc. All of these can require some adjustment of the basic F&S in order to get a good cut (and avoid wiping out the filters).

#25

This has been a plan of mine for a while, but as you say “my list is long and my time is short” :wink: . In v carve there is a start of a new library where it would be per material. We just need people to figure all that out meticulously.

#26

Woodsaver tool set for lathe, to make nesting bowls and conserve beautiful, exotic, scarce wood.

#27

I wanted to thank Tom Cook for bringing to my attention the need for donations for sandpaper for the Festool sander. I do not do a lot but I now realize that at .75 a sheet if I use ten sheets a week that really adds up. The 50 dollars a month I pay is only for the opportunity to utilize the many tools that are available. That is about the only resource I use that costs money but never the less, it is an expense. I donated a trailer load of wood but that does not offset the expenses we have for materials. I think more reminders need to go out to members so they have a better idea of what the costs are to replenish materials. I will be dropping off a check the next time I am there. I love the options MakerSpace has given me.
I also would like to post some things I have made in the Woodshop but not sure how to do so. Thanks, Jeff Whitcomb

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