70e plastic flywheel, 3-D printable?

[woods works]

This came in to the shop last week with the recoil not engaging. Figured replace spring and out the door----not



If this could be reproduced, there is a need! I would buy at least 2.

 

[Boleclimber]

I have been wondering the same thing for years. I have a spare fan and have often wondered if it can be somehow scanned or molded for reproduction.

 

[bigrichard81]

I have a few different 3d printers at my disposal as well as my own personal 3d printer. I can only do ABS or PLA (feel free to google about their pros/con's) but if you get me a rough sketch with dimensions I could CAD it up and see if it would work.

 

[Chris-PA]

I have my doubts about strength spinning at 10,000rpm, but with the cover on it should not be too dangerous.

 

[bigrichard81]

Yeah, 3d printed parts tend to have less strength than injection molded parts. I think in this application it will depend on how much material you have hanging out past the supported area. I think it would be interesting to try at least.

 

[woods works]

Here are some pics of a good one to give you a better idea of what's needed. I would think increasing the thickness of material could be done if needed to increase strength without a performance loss. If you think its worth a try I'd be willing to send this out for you to play with. Of course I'd need your best boy scout promise it would be returned. If not I'd have to call my wife's "cousin" Vinny down there in Pekin

 

[bigrichard81]

I'll pm you my address. I'm not familiar with this saw so let me know where I can and can't add material. I got to thinking is balance super critical to this or will an as-printed part be balanced enough?

 

[half_full]

would a heavier fan slow acceleration? Just a thought. I know plastic is not too heavy to begin with.

 

[Jeff Lary]

Don't worry about safety Chris , as much care as this poor ole saw obviously gets from the owner I doubt he would notice anything wrong even a catastrophic failure. I cannot imagine with so much wood dust crap compacted into there that something else has not failed before.

 

[woods works]

Making this with a printer was just a thought after seeing another thread here with a flywheel puller made. If that actually held up then maybe this fan would too. Never had anything made this way in my hands, so that's why the big "?" on the first page.

Yah, the saw on the first page was sure neglected. It might have survived actually. There was only 2 of 4 screws left on the fan and both loose. One was laying in the cover and one missing in action (maybe buried in the gunk) I'm leaving it as-is til the customer see's it. But I'm thinkn this one is going to end up in the parts-saw pile.

 

[Jeff Lary]

yea I thought after I posted that , that it may sound like I was after you I was not. I just cannot believe people pay hundreds of dollars for a saw then neglect it like that. The guy might not be a class a service tech but at least clean it out once and a while. You would do well if he just gave up on it and left it for you as a parts saw.

 

[Bob95065]

Anyone get a model made for the fan? I may try to take this up once things slow down at work.

I am a mechanical engineer in the metrology department where I work. We use 3D measurement equipment including scanners to take 3D data. They have several 3D printers here that they encourage employees to use for personal projects. It would be fun to try to make a fan based on a scan of a OEM part.

I have a 70E with an intact fan. I thought I read here that the fan design had changed 3 times? Did Jonsered use more than one design during the run of the 70E? If so I would want to get one of each to scan.

 

[z71mike]

I see a grenade happening.

 

[old-cat]

I see a grenade happening.

NON SENSE! It will work

 

[fordf150]

if a 3D printer can make a working gun i dont see why this couldnt be done.

 

[Bob95065]

I haven't read it yet but I found this online: https://www.academia.edu/6209168/Me...ters_under_realistic_environmental_conditions

 

[Bob95065]

Another: http://3dprint.com/14533/3d-print-material-test/

 

[bigrichard81]

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.



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)

 

[olyman]

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.
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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)

hope he vids the results!!!!!!

 

[bigrichard81]

hope he vids the results!!!!!!

Me too!