70e plastic flywheel, 3-D printable?

[Chris-PA]

Woods Works sent me the flywheel and fan, and I made a model. Why did I make a model rather than 3d scanning it? I have a few laser scanner and blue light scanners I can use, but the real reason lies in 3d printing. The low end 3d printer I am printing this on (~$2000) always prints on center. Unlike cnc milling, there is no radius compensation in free softwares (Repetier…) so your internal features are undersize and/or your external features are oversize. There are a few tricks to minimize this, but the easiest is to simply build the model with the offsets built in. Using a 3d scanned part would yield a part that is too small on the IDs and too large on the ODs. I do not have software at my disposal that easily modifies scanned point cloud data like a scanner would output. For that reason I took half an hour one evening and modeled up a close replica of the original, with my vanes being a little thicker (read stronger), but otherwise similar to the original. The problem with this method and the tight slip fit Jonsered intends, is I have had to print a couple to get the size dialed in. These are printed in ABS so there should be a decent amount of strength and pretty good temperature/fluid resistance, but it is not the same material as the Jonsered part. It appears the part was originally injection molded out of some type of nylon/uhmw type of material.
View attachment 394325

View attachment 394326
Will it grenade? I don’t know. But I do know if we never try, we will never know. The plan is to get a few of these over to Woods Works and have him try it out. I don’t own a 70E so I can’t do it on my saw, but like any research effort, I have a certain amount of trepidation that it could all blow up in glorious fashion (emphasis on glorious)

Nice job! How long did that take to print? I'm printing a fixture to hold an extrusion on a cutoff saw now - about 8hrs for each half!

 

[TIMBERTRON]

INTERESTING

 

[Bob95065]

Woods Works sent me the flywheel and fan, and I made a model. Why did I make a model rather than 3d scanning it? I have a few laser scanner and blue light scanners I can use, but the real reason lies in 3d printing. The low end 3d printer I am printing this on (~$2000) always prints on center. Unlike cnc milling, there is no radius compensation in free softwares (Repetier…) so your internal features are undersize and/or your external features are oversize. There are a few tricks to minimize this, but the easiest is to simply build the model with the offsets built in. Using a 3d scanned part would yield a part that is too small on the IDs and too large on the ODs. I do not have software at my disposal that easily modifies scanned point cloud data like a scanner would output. For that reason I took half an hour one evening and modeled up a close replica of the original, with my vanes being a little thicker (read stronger), but otherwise similar to the original. The problem with this method and the tight slip fit Jonsered intends, is I have had to print a couple to get the size dialed in. These are printed in ABS so there should be a decent amount of strength and pretty good temperature/fluid resistance, but it is not the same material as the Jonsered part. It appears the part was originally injection molded out of some type of nylon/uhmw type of material.
View attachment 394325

View attachment 394326
Will it grenade? I don’t know. But I do know if we never try, we will never know. The plan is to get a few of these over to Woods Works and have him try it out. I don’t own a 70E so I can’t do it on my saw, but like any research effort, I have a certain amount of trepidation that it could all blow up in glorious fashion (emphasis on glorious)

Can you post the 3D printer file for the fan?

 

[bigrichard81]

Can you post the 3D printer file for the fan?

I'll put the file up later this evening but keep in mind it has been corrected/calibrated to the printer I use.

 

[Bob95065]

I understand. It will be a great place to start from.

BTW What printer are you using?

 

[7sleeper]

This is sure an interesting topic!

7

 

[Matt B]

This is good stuff. There are so many NLA plastic parts in older saws. Looking fwd to seeing how you get on.

 

[bigrichard81]

So here is the .stl file (stereolithography) that most 3d printing softwares require. If you want the file in another format let me know, and I can save it in editable file.
I just noticed it won't let me upload the stl so I just put it in the zip file.

<file removed>

 

[Boleclimber]

What would the cost be to have the fan printed? 16 hours of printing sounds very pricey.

 

[bigrichard81]

What would the cost be to have the fan printed? 16 hours of printing sounds very pricey.

With appropriate settings this should take ~5 hours to print. I don't know if it is even going to work so I'm not going to sell them.

 

[woods works]

hope he vids the results!!!!!!

Me too!

Waiting..................., PATIENTLY waiting The 70e and 66e however can hardly stand the wait
Got the 12" x 15' red oak log also WAITING to get cut into a bunch of cookies

 

[MechanicMatt]

I got a good buddy at work who needs a fan for his 70e, if you ever decide to sell them please let us know.

 

[bigrichard81]

Waiting..................., PATIENTLY waiting The 70e and 66e however can hardly stand the wait
Got the 12" x 15' red oak log also WAITING to get cut into a bunch of cookies

I will finish up and send a bunch on Tuesday/Wednesday (USPS is closed on Monday). I'm hoping Denny will post some videos of the first time he firesmthem up as that may be as long as they last .
Someone earlier in the thread mentioned a concern about weight. I haven't measured them but doing the old one-in-each-hand method, the printed one is lighter primarily due to the fact in injection molded parts have a 100% fill rate of solid plastic but 3d printed parts can be anywhere between 5-100% with the parts I printed being either 50 or 100.
We'll find out soon enough I guess.

 

[Chris-PA]

I will finish up and send a bunch on Tuesday/Wednesday (USPS is closed on Monday). I'm hoping Denny will post some videos of the first time he firesmthem up as that may be as long as they last .
Someone earlier in the thread mentioned a concern about weight. I haven't measured them but doing the old one-in-each-hand method, the printed one is lighter primarily due to the fact in injection molded parts have a 100% fill rate of solid plastic but 3d printed parts can be anywhere between 5-100% with the parts I printed being either 50 or 100.
We'll find out soon enough I guess.

How many outer loops and top/bottom layers did you print?

 

[bigrichard81]

How many outer loops and top/bottom layers did you print?

5 outer and inner and 4 top and bottom.

 

[Chris-PA]

5 outer and inner and 4 top and bottom.

I've been playing with infill settings - these are some jaw adapters for holding 4" aluminum extrusions on a cutoff saw - they were printed with 3 outer loops and 4 top and bottom layers, but only 15% infill. They are amazingly strong - they were printed with PTEG:

 

[Cantdog]

Very cool....watching with great interest....Do you think this will need to be balanced....at least statically?????
Lighter will allow faster acceleration but a very slight loss in torque....the latter being probably a non issue with a 70E...however bit more zippy acceleration never hurts......hope it stays together at speed......

 

[LegDeLimber]

Has anyone done the surface smoothing on these??
You guys that know what stress raisers and surface textures or nicks and scratches
can do to a part.
What this involves is basicaly using a solvent that will soften the plastic
and then either using the solvent for wiping the part, so that it softens the surface
(you don't want to soak it deeply) and then as you wipe, you get that slight bit of flow
at the surface and this lets you rub it to a smooth(er) finish.
Some people have used the method of putting small amount of the solvent
into a containr that's large enough to permit placing the part inside
But without it actually touching the solvent (needs good air flow like spacing inside)
Now you close the container for a predetermined time and let the solvent
evaporate inot the container and thus it slightly dampens the plastic
which lets the plastic sort of loose the texture details a bit.

But whatever you do, it'll hold up better with a slick finish.
But don't use the wrong solvents , which could actually weaken the part.
You'll need to ask the plastics people what is the correct elixer.

 

[bigrichard81]

Has anyone done the surface smoothing on these??
You guys that know what stress raisers and surface textures or nicks and scratches
can do to a part.
What this involves is basicaly using a solvent that will soften the plastic
and then either using the solvent for wiping the part, so that it softens the surface
(you don't want to soak it deeply) and then as you wipe, you get that slight bit of flow
at the surface and this lets you rub it to a smooth(er) finish.
Some people have used the method of putting small amount of the solvent
into a containr that's large enough to permit placing the part inside
But without it actually touching the solvent (needs good air flow like spacing inside)
Now you close the container for a predetermined time and let the solvent
evaporate inot the container and thus it slightly dampens the plastic
which lets the plastic sort of loose the texture details a bit.

But whatever you do, it'll hold up better with a slick finish.
But don't use the wrong solvents , which could actually weaken the part.
You'll need toask the plastics people what is the correct elixer.

I hadn't planned on doing much surface prep. However if woods works has some acetone, that works with ABS to remelt and smooth just the surface.

 

[bigrichard81]

I hadn't planned on doing much surface prep. However if woods works has some acetone, that works with ABS to remelt and smooth just the surface.

I should clarify the reason for not planning to do much surface prep is I think the failure mode on this will be internal delamination not surface crack propagation. With that said I suppose it doesn't hurt to do the surface prep just in case the failure mode is a surface propagated crack.