make shrink-on sleeve

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Gwhite
Posts: 372
Joined: Tue Jul 11, 2017 3:38 pm

Re: make shrink-on sleeve

Post by Gwhite » Wed Jan 26, 2022 11:12 pm

I iterate a lot, but it's primarily on two fronts:

1) I need to print a part that mates closely with an existing piece of hardware. Sometimes I can't get access to all the measurements I need for a good fit. Even if I can, the precision of 3D printing is such that I need to print at least one prototype and then adjust a dimension or two. Very often, I'm trying to mate with a surface with multiple curves. I have a set of metric radius gauges, but that will often only get you in the ball park when the curvature changes rapidly. I also use dovetails to build up larger models, and if I want a secure fit, an iteration or two is often required.

2) Dealing with unknown material properties. I make a lot of parts that snap into place, or have built in "springs". I'm printing Rev. 2 of a part right now where the part that is supposed to flex and snap into place is too stiff. I just cut the thickness down, and I'll see how that turns out. I've got another design where the spring needs to be stiffer. It was marginal with the PLA I first printed it with, and the PLA "Plus" I'm currently using is stronger, but more flexible.

I spent a lot of time slicing my models up into pieces to quickly print test articles to evaluate fit, strength, or springiness. When it comes time to run a large complex print, my odds of success are greatly improved.

jferguson
Posts: 247
Joined: Mon Mar 30, 2015 7:26 pm
Location: St Petersburg, FL

Re: make shrink-on sleeve

Post by jferguson » Thu Jan 27, 2022 10:40 pm

Gwhite, I assume you are doing this for business, not solely your own amazement?

Gwhite
Posts: 372
Joined: Tue Jul 11, 2017 3:38 pm

Re: make shrink-on sleeve

Post by Gwhite » Thu Jan 27, 2022 10:58 pm

I don't make stuff commercially, but I'm the gunsmith for a college pistol team. I'm constantly building stuff for the team, as well as fixtures or parts to help repair pistols. I also have plenty of my own projects, mostly accessories for my shop & printer. My wife no longer complains about the money I spent on the printer by virtue of a steady supply of house repair parts, kitchen gadgets etc.

jferguson
Posts: 247
Joined: Mon Mar 30, 2015 7:26 pm
Location: St Petersburg, FL

Re: make shrink-on sleeve

Post by jferguson » Fri Jan 28, 2022 2:08 am

Gwhite, isn't is amazing how often one can spend days searching the web for a particular part or device and then realize that it can be made? I still don't think of making something first.

Gwhite
Posts: 372
Joined: Tue Jul 11, 2017 3:38 pm

Re: make shrink-on sleeve

Post by Gwhite » Fri Jan 28, 2022 2:30 am

If I can buy it, I usually will, although sometimes poor quality pushes me into making my own. I've got a huge list of things that are one-of-a-kind, or are no longer made to keep me busy.

As an example, I just finished making a fixture to measure the recoil spring force in the bolts for Benelli .22 target pistols. The college team has over 20 of them, and Benelli has stopped exporting parts to the US. The springs have gone through numerous design changes over the years, and some springs don't work well with the ammunition we can get.
Bolt Spring Force Tester w Gauge (sm).jpg
It uses a trigger pull gauge to measure the force. I now have a growing set of data on what springs & forces work with what ammunition. That should allow me to order custom springs that will keep us going for another decade or two.

jferguson
Posts: 247
Joined: Mon Mar 30, 2015 7:26 pm
Location: St Petersburg, FL

Re: make shrink-on sleeve

Post by jferguson » Fri Jan 28, 2022 4:18 am

Gwhite, that's very nice. Is the aluminum grip ?? just beneath and in front of the gage part of the original gage "assembly" or from some other device?

Don't you find making these things really rewarding, especially when they work well? I didn't doubt that the Nikon lens "grip" would . took it on a trip and found it was perfect. It's still tricky to get sharp photos hand-holding it but if I take a bunch of shots and have been careful with focusing, many of them will be just fine.'

Do you have experience with DuraCoat? I bought the paint in the two part form and the filler as well. The aluminum tube on the grip was extruded. I had no good way to get rid of the grooves on the outside so my plan was to use DuraCoat filler and then when I had a good surface to use the matte-black for a finish.

I suppose it's childish of me, but I really wanted to make it look "official" and thought a good paint job would do the trick.

Have you tried making target pistol grips. I've been away from shooting for 60 years so don't know what equipment looks like today, but thought it would be fun to make the sorts of grips which Hammerli's used to have.

What do you use for cad and what slicer?

Gwhite
Posts: 372
Joined: Tue Jul 11, 2017 3:38 pm

Re: make shrink-on sleeve

Post by Gwhite » Fri Jan 28, 2022 4:10 pm

jferguson wrote:
Fri Jan 28, 2022 4:18 am
Gwhite, that's very nice. Is the aluminum grip ?? just beneath and in front of the gage part of the original gage "assembly" or from some other device?
The complicated silver piece clamped into the fixture is the pistol bolt. The tube sticking out on the left end of the bolt is a guide tube that houses the recoil spring. The force gauge has a 3D printed adapter with a brass insert that pokes into a hole in the end of the tube. You slide the gauge to the right, stopping when the tube is compressed 3 mm, or when it is fully telescoped into the bolt. Those positions correspond when the the bolt is closed, or fully open in recoil. If the closed bolt force is too low, you get incomplete combustion, lots of carbon build up, and the recoil won't cycle the pistol properly. If the force is too high, the bolt won't come back far enough to cycle things properly. There's a happy middle ground, but it can depend on the ammunition. We have some pistols that will only work well with expensive German ammo that costs over 3 times what we can get good Mexican ammo for. They just stopped importing the German stuff. We have enough left for this season, but by next Fall, I need to have the springs sorted out so we don't need it any more.
Don't you find making these things really rewarding, especially when they work well? I didn't doubt that the Nikon lens "grip" would . took it on a trip and found it was perfect. It's still tricky to get sharp photos hand-holding it but if I take a bunch of shots and have been careful with focusing, many of them will be just fine.'
When I can solve a problem with a new widget, I'm a happy camper. Big problems or small, it doesn't matter. I know people who love solving crossword puzzles & other brain teasers. I prefer to keep my brain busy solving real world problems. Making devices to make life a little tidier or easier is good, but I get the most fun out of solving problems nobody has bothered with before. None of them are particularly earth shaking, but the problem solving is fun, and even more so when the final result is a tangible object. On a really good day, it's something I can make additional copies & share with the students & friends. Sometimes they are just one-offs for friends to repair something that broke.
Do you have experience with DuraCoat? I bought the paint in the two part form and the filler as well. The aluminum tube on the grip was extruded. I had no good way to get rid of the grooves on the outside so my plan was to use DuraCoat filler and then when I had a good surface to use the matte-black for a finish.

I suppose it's childish of me, but I really wanted to make it look "official" and thought a good paint job would do the trick.
I haven't used Duracoat. It's pretty popular for firearms & should hold up well to wear & tear, but I'm not sure if the solvents would attack common 3D print materials. if you are just using it on the aluminum tube, it should be fine.

I like my prints to look nice, but I'm mostly a "function over form" guy. If it serves the purpose well, I'm happy. I often end up using whatever color is on the printer, even though I might prefer something different. I haven't done very much in the way of finishing for cosmetic purposes. I use Floetrol as a sealer to prevent grime from embedding in the layers, and it also works to seal prints if you want to use a marker to fill in lettering.

I think I got some of this from an old professor. When I was in grad school, I was a teaching assistant for a course on high speed photography in Harold Edgerton's lab. He basically invented flash photography and high speed stop motion work. Many of his photos are quite beautiful, but his real interest was in using photography to solve problems and understand things the eye couldn't see. If he could get a grainy black & white photo that showed what was going in some mechanism or process, he was ecstatic. If the picture turned out to be beautiful as well, that was a bonus. If he had a lovely photo that looked good, but didn't provide useful information, it was of little use to him.
Have you tried making target pistol grips. I've been away from shooting for 60 years so don't know what equipment looks like today, but thought it would be fun to make the sorts of grips which Hammerli's used to have.
Another college pistol coach now has a full time business making 3D printed grips & a few other shooting accessories ( a few of which I designed).
https://www.precisiontargetpistolgrips.com/
The team I help coach has quite a few of his grips.
What do you use for cad and what slicer?
Because I'm affiliated with a college, I can use Fusion360 for free.

For slicing, I'm a big fan of Simplify3D, but the company is run by an idiot, and I'm stuck with the "latest" version, which is about 3 years old now. I also use PrusaSlicer. It's OK, and it will do day-to-day prints just fine, but if I need to do something fussy, or I'm having issues with a particular print, I fall back on S3D. I try to avoid supports, but S3D gives you way more control than PS. PS hides a lot of things under the hood, and the defaults are generally pretty good. If you need precise, layer by layer control, I think S3D is still the best. I just wish they'd finally get their act together & release Version 5...

Phil
Posts: 214
Joined: Mon Sep 19, 2016 7:49 pm

Re: make shrink-on sleeve

Post by Phil » Fri Jan 28, 2022 5:20 pm

Another college pistol coach now has a full time business making 3D printed grips & a few other shooting accessories ( a few of which I designed).
https://www.precisiontargetpistolgrips.com/
The team I help coach has quite a few of his grips.

Ha! I thought about doing that about 8 years ago. I guess I went another direction; I 3-D print silencers. (I am licensed.)
I also make things for aircraft. I have sold hundreds of these:
IMG_0817.jpg
They also take painting and laser etching. I am working on other items, as well.

Gwhite
Posts: 372
Joined: Tue Jul 11, 2017 3:38 pm

Re: make shrink-on sleeve

Post by Gwhite » Fri Jan 28, 2022 6:44 pm

Nice switch caps! How do you do the lettering, dual filaments?

I'm surprised the silencers don't melt, unless you have access to a sintered metal printer or some such.

I've printed lots of stuff with inset lettering, but coloring them is pretty tedious. If you don't seal the print with something like Floetrol, the ink wicks into all the little gaps & you end up with a mess. Even with a couple coats, it's hard to "stay between the lines" if the lettering is small. I've found some fine tip silver paint markers that work OK, and you can whittle the tips to be even finer.

jferguson
Posts: 247
Joined: Mon Mar 30, 2015 7:26 pm
Location: St Petersburg, FL

Re: make shrink-on sleeve

Post by jferguson » Fri Jan 28, 2022 11:33 pm

Hi Gwhite. thanks so much for the detailed response to my questions. I looked up Benelli on the web and I can see what you are doing. Pretty Slick.

i've been modeling with Creo which I rent - $$. I need it for its cnc CAM package for the mill. I used to use it for stl modeling but more recently I've been using Onshape which if you don't mind your files being public is free. It's wonderful, intuitive (at least for me), quick and produces drawings with whatever views you'd like very quickly.

Creo is good in that regard but i find I can do something in Onshape in 1/4 the time it takes with Creo.

I've been using Simplify3D since I bought the M2. Pretty happy with it although every once in a while it cannot find my license. Guy at Simplify has always responded close to instantly.

Egerton, wow. you must have been at Tech some years ago. Fill me in.
I'll share some of the stuff I do.

This site has gone a bit moribund and I suppose the guys who used to get all worked up about OT postings have gone away. But then this is my thread and we ought to be able to do anything we want which isn't contrary to MakerGear's business interests.

john

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