Powermatic undergoing tune-up

Woodshop
#1

DMS possess an awesome Powermatic table-saw. This cabinet saw is considered by many in the industry as one of the best ever produced. Our saw is sick and has been for a very long time. Repairs on this saw can become very involved, so it isn’t something taken lightly.

The symptoms our members encountered were numerous. It always took excessive force to raise the blade. The blade tilt had stopped working since the tilt adjustment wheel was free-spinning on its shaft.

Basically wood dust has been compressed between the moving part of the saw and caused damage. Unfortunately members just cranked harder as the handles became difficult to turn. This resulted in the two main shafts that control both the depth of cut and the angle of cut to be damaged beyond repair. New shafts are currently being created by our very own machine shop at DMS under the supervision of @TBJK. Too cool isn’t it? If any members bake cookies… just saying.

Here are some pictures of the machine in its current state awaiting new parts and a very deep cleaning.

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Dado Blades for Table Saw
Cheap and easy 3D scan?
#2

Fantastic work! Thank you guys for all that you are doing!

#3

Update on the Powermatic Table Saw

Great news, the Powermatic is one step closer to returning to duty. As shown in the picture from the last post, the trunnion was a real mess. The trunnion is the heart and soul of a quality table saw. Years of neglect had resulted in wood chips and saw dust almost fusing to the cast iron assembly. Incredible friction developed between the metal parts. This was the reason that saw was so difficult to raise, lower and tilt. If the cleaning would have taken place three to fours years ago, we might not have had the failure with the shafts that were destroyed.

A new ninja minion appeared and just handled the issue late tonight. Here are a couple of before and after pics. It went from nasty to clean in one session.

When the ninja began:

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After the cleaning session:

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Notice the difference?

But evidently, this still isn’t good enough for the ninja. Nothing but doing this correctly will suffice. The parts will be undergoing an advanced cleaning in the DMS Vapor Hone machine. This machine is managed and maintained by our Scottish buddy @procterc and crew in the Metal Shop. If you are unfamiliar with what and how the Vapor Hone works, check out this video. You never know when you might need to clean a cast iron skillet or other metal item. Just reach out the @procterc or any member of the metal shop they will be more than happy to help you out with your project.

Who was the ninja minion you ask…

None other than our very own @yashsedai - All you wood shop folks let him know his effort is appreciated the next time you see him.

After the cleaning, the next step is installing the new shafts being machined by @TBJK and crew in machine shop. This has taken a bit longer than anticipated due to a special tool being required and not being readily available.

That is all the news, but rest assured there wouldn’t have been any tonight without the ninja minion unexpectedly stepping up to the plate. Please keep in mind that nothing gets done without members leading the charge. Have an idea, just run it by the committee chair in charge of the area. Good chance you will solving DMS issues no time flat.

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#4

Remember to pull the bearings and tape the worm drive if its going in the vapor hone, otherwise you will have abrasive in the bearings and a rough surface on the gears. I use wire wheels or schotchbrite on gears and sheaves to keep the surface smooth.

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#5

^ This sounds important.

1 Like
#6

Exciting stuff! good work @yashsedai ! A year ago, I bought an old Powermatic 66 and refurbished it, so i’ve been through this process once before–I may be able to lend a hand if necessary, although it looks like the process is already in capable hands. This may be a good opportunity to replace the arbor bearings as well, if they’re at all gummed up (My PM66 is a 1983, and if they didn’t change the design, the bearings are 20mm ID, 40mm OD, 14mm wide). Right before reassembly we should also make sure to put some dry film lube on all of the faying surfaces incl. worm gear drives and trunnion bearings.

#7

as a side-note, I reached out to @lukeiamyourfather about 3d scanning the table saw and parts with the idea of designing a 3d-printable (or otherwise manufacturable) dust collection chute.

question 1: Would we have the time to scan the cabinet, trunnion and lift mechanism or are those already back together?

question 2: Is there any desire to actually do this? The PM66 is notoriously bad for dust collection and this could help capture a lot more dust and keep it out of the bearings, possibly preventing failures like this in the future.

#8

There should be time. I have not got that far on machining the new parts. I have to order a woodruff key cutter to manufacture it.

For those who are wondering, why don’t we just buy the replacement parts, well they are discontinued. I looked into that myself to make sure it would be worth my time to do.

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#9

Funny thing is we haven’t even had the saw for that long; three years ago that spot was taken by a Delta table saw.

Making improvements to dust collection would be incredible. I can’t count the number of times I helped someone unpack that mess of a cabinet. The flow of dust to the front of the cabinet is ludicrous enough I wonder how much actually makes it to the dust collector

1 Like
#10

@daveand, why not? As @hon1nbo says, the saw cabinet is quick to clog up with dust. If the 3D scanning becomes to burdensome, for whatever reason, and your objective to solve this issue and not just learn a new 3d workflow, I also have really nice laser measuring gear to do manual take off.

Get after it sooner than later, for when the parts arrive this baby is going back online:) Please let me know if I can be of help.

#11

I expect it was going wonky way before DMS procured it. We just pushed it over the edge:)

#12

I bet we could easily clone this, or simply buy it.

Corrugated plastic board (an old election sign, perhaps) might suffice.

#13

Yea the dust collection is terrible since it’s just a hole in the back of the case, and that’s it, but if we’re making our own and it’s attached to the arbor assembly just make sure it has clearance when blade at full height and full tilt, that’s when it’d be the closest to the table, but huge respect to any involved in this, I always knew it was a super labor intensive project but glad to see there’s people with the know how willing to devote time to helping get one of the best table to ever be made back to if former glory

#14

Yeah, I’d seen this before as well, but this doesn’t keep the dust away from the bearings of the saw. I was wanting to design something that fit onto the trunnion and around the saw blade and had a fitting for a flexible hose that piped to the 4" hole in the back of the cabinet. I just know that with the trunnion rotated to 45°, the clearance can be minimal for any extra fittings, which is why I wanted to get a 3d scan of the parts. I’m a professional design engineer so I’d like to volunteer what services I can add by designing that fixture, and I have experience designing for 3d printing, so there’s a chance I can design something that’s actually assemble-able and manufacture-able.

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#15

Almost anything would be an improvement compared to what is there now.

#16

I’ll reply here instead of PM in case other folks are curious. The LIDAR based scanner isn’t a good option for this. The time of flight combined with SLAM will give you a centimeter of accuracy give or take depending on circumstances. Pretty good for buildings and streets but not so good for small mechanical parts.

Other scanning methods with millimeter or better accuracy would be better for this kind of work like laser triangulation or photogrammetry. Unfortunately this isn’t something I can help with for the foreseeable future. Never hurts to ask though.

Edit: You might be shocked at how much you can get out of basic measurement instruments (compass, caliper, ruler, paper and pencil to stencil things, etc.) and a couple of hours of time. Unless the shapes are incredibly complex the 3D scanning isn’t worth the effort.

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#17

Homestly if it were me, I’d just go the old tape and thin plywood mock up then once that’s fit to perfection, you have the exact dimensions and shape to create a 3d rendering(fusions my go to) but that to me seems like the easiest, there’s a lot of trial and error but that way you can get a extremely custom perfect fit and see it in real life before actually committing to it

1 Like
#18

As far as worm gear and the partial gear, these are standard gear profiles, meaning take the basic dimensions for these and you can import the shapes into a CAD model and match the dimensions and you’ll have perfect profiles. No need to scan. The other dimensions aren’t that critical for what you’re doing just meauresure
Worm gear gometry
More gears
Worm gear formula table
Worm Gear Measurement

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#19

Oh my bad I was talking about fationioning some sort of dust collector shroud to funnel the dust,

#20

@Photomancer, as @Chris_Fazio mentioned, I was just talking about scanning the cabinet, table, trunnion and lift mechanism parts. The table, trunnion and lift mechanism are castings and have more organic shapes that just take time to measure and model.