Dick thanks for the tips. I had fun playing with the TinkerCAD. Way easier to design this gear than sketchup. Not to mention it exports in .stl which is what my printer guy needs.
Putting all the shoulder on one side I think could work well and help me reinforce it should I decide to put a brass sleeve on it. Ii don’t see why it can’t be that way.
As to printing materiel he said ABS is no problem his printer will do it.
Dick thanks for the tips. I had fun playing with the TinkerCAD. Way easier to design this gear than sketchup. Not to mention it exports in .stl which is what my printer guy needs.
Putting all the shoulder on one side I think could work well and help me reinforce it should I decide to put a brass sleeve on it. Ii don’t see why it can’t be that way.
As to printing materiel he said ABS is no problem his printer will do it.
Yep, my burn out oven will incinerate the ash for a clean cast, stinky though! (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-sealed.gif)We should experiment and print them 5-10% larger to allow for metal shrinkage as it cools through the quench. Larger for Masters as the rubber and wax add to the less. Er … all shrink some… In Sterling it was about 10% total from mold to casting. Bronze is new to me. It’s specific gravity will help us determine it’s rate.
Yellow brass is another option.
I’m a small time operator with big vision, interrupting a production line for a one off is hard, but I made custom jewelry for 25 years … all little jewels to me! (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-money-mouth.gif)Kidding!(http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)
Getting closer, told you about the Sterling Silver Driver. Just started a thread about it’s design. I figgured it’s time for show and tell. Years ago I added gear heads to my toy lathe so I can mill hard wax at slow speed. Going to cast and then inlay between the spokes a driver for my hat band.
John
OK John,
I am all for this idea. Like I said I would rather have a bronze or brass gear over plastic. I might have Peter (my printer guy) print some at the correct size that I can use for now but then have him print a few in a larger size to allow for shrinkage in the casting. Now with the larger size is that all dimensions. So if I create the exact gear I need would I just scale it up 5-10% (whatever we need).
I will work on this.
I think at most each gear lobe will need a quick blue-pumice polish for a quick shine. What ever you see in the print, you’ll see in metal.
Please remember my copd keeps me at half speed, I’m not complaining, just ex splainin’!(http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)
John
I have no expectations John. I will have him make me some that I can use immediately. But I will definetly have him make some you can play with.
It helps when you zero out your calipers when you measure. I have an old school analog dial type caliper and forgot to zero it.
So now here is the gear
It is 14.5mm OD overall. Overall width is 7mm. Shoulder OD is 8mm which will allow a 11/32 .014 wall K&S brass tube to be fitted over the shoulder. Tooth width is 3.9mm and shoulder width then is 3.1 mm. 16 tooth. Tooth profile I got as close as I could to the original hard to make accurate measurements. It looks good to me.
Good going, Devon!
Dick Friedman said:
Good going, Devon!
Thanks to you Dick. That program could prove to be very useful. I am learning to like Sketchup but for this gear this was way easier have a gear generator. Took less time and made a better product and has the exportable .stl file that my printer guy can use straight away. So a big thanks.
I ended up getting the wheel of using the Sean method because my split ring pliers didn’t open wide enough to use the Joe method. I was expecting a bit more resistance. It popped right off with the first tap. I am willing to bet if I wanted to remove the other side it would be a matter of using my wood inserts for my vice and pinching the axle and tapping the other side off. Still not sure why I would want to do this but if I need to I know I can.
I am actually getting a bit excited about this. It would be cool to have this loco running. Considering what I paid for the big box of junk it came in it would be a cheap loco. I paid $20 bucks for the box.
Today I got four of my gears printed in ABS. Now, if my 2nd trolley just had a motor!
Dick,
I will be very curious to know how the ABS ones do. My printer guy Peter says he has had issues with ABS layers de-laminating. He has never tried it on a gear so who knows. I need to ask him the material he printed mine in. It not nylon, PLA, or ABS. He has four made and from the photos they look great. He is sending them to me for a test fit and see how they mesh with the mated gear. If all goes well he will print me ten or so of them. Then I am sending a bunch that are 3% and 6% larger to John to see if he can cast them in brass.
Either way if the plastic works then great but better still if John can cast them then we will have a whole new life to breath into these cracked gear locos. Between the TinkerCADS ease of design and 3D printing being reasonable (even though mine are coming from Denmark) and the possibility of brass this is just very cool.
Makes me want to make the whole set just to see if I can.
OK so an update, my gears arrived from my printer guy Peter in Holland. I believe he said that this material is a PLA blend with something else that will make them stronger than straight PLA and does not delaminate like ABS. They look great. It amazes me that I can design something on a computer and email the file to a man in Holland that then puts it on a printer and spits them out and then mails them back to me. How truly small the internet has made the world. He sent me the four test prints. I will install one hopefully very soon and figure out how to power the loco. Might have to rig it with one of my RC units and a battery. I don’t really have any way to test it as is (DC).
I will let you know
I first took the gear and meshed it with its mated gear and I think it is a great fit. So I went to put it on the axle. I wouldn’t go on even with light tapping. I rolled a piece of sand paper and honed it out til I could tap it on. Still a bit to tight in my opinion. But I am leaving it. If it splits I will sand the next one a little more. But the design works great. I put the shoulder to the outside and even though all the shoulder is on one side it has plenty of clearance and is not an issue. Should I need to I can add the brass tubing with ease.
I will need to get the loco running to make a final appraisal but I think this is going to work. Just as Dick is having success I believe I will also. We might have a real solution to the cracked gear syndrome. Making the gear in TinkerCAD was easy and it exports in a file readily readable by the 3D printer. so this really should be an easy and inexpensive solution.
Once I determine that the gear works well I will have Peter print me a few extras and then send John C some that are oversized and have him cast them in brass. IF those work then we really will have a great solution for one off gear replacement that wont break the bank and require someone to buy 10,000 of them
Both are gears Peter printed. one installed one as I received it. Very clean print. Nothing to trim or clean
Glad the prints worked out well. I had to enlarge the hole by about .5 mm. (Perhaps .75mm would give a little more room.) The ABS ones were still a little snug, but a light tap got it on OK. I’m sure there is a future in our hobby with 3D printing.
