Lunchbox with Ampro parts. Now with more Pumpkin!

[Grumpy pants]

Great thread this 

[Phil_H]

I remember putting a Hornet Pinion on my stock LB with a 13t Brushed.....it got very hot...very quickly! lol

I've not managed to kill a Chinese Brushless yet with any combination. My TA04 runs a 40t Pinion on a 3s Lipo with relative ease!

 

[Grumpy pants]

Fat thumbs .

Duplicate entry. 

[Kingfisher]

9 hours ago, TheMidnight Pumpkin said:

Sometimes I will add a bit of metal when gluing parts for extra strength.....forgot to add that to my previous post. In this case you can't really drill for an internal metal support. So maybe a little piece of paper clip glued on the side will keep it together.

I forgot that I had some of this glue on hand. 

http://www.homedepot.com/p/Loctite-2g-Plastics-Bonding-System-681925/100371829

I used it a while back to fix broken tabs on a 1:1 car interior panel. I'm going to give it a try this evening. Thanks for the idea about adding metal support.

[Country Mike]

heatshrink ! a few layers too.

[nowinaminute]

8 hours ago, Kingfisher said:

I forgot that I had some of this glue on hand. 

http://www.homedepot.com/p/Loctite-2g-Plastics-Bonding-System-681925/100371829

I used it a while back to fix broken tabs on a 1:1 car interior panel. I'm going to give it a try this evening. Thanks for the idea about adding metal support.

I was going to suggest a 2 part adhesive. If that stuff doesn't work I HIGHLY recommened JB weld, it has been amazing in my experience. That Nikko Dictator with double brushless I posted on the previous page, it was a wreck when I got it, the gearbox case was cracked where the lower A arm attaches on the front gearbox, if you flexed it you could see inside the gearbox it was that bad. I cut a paper clip up into short lengths and uses some super glue to place the them along the crack on the inside of the gearbox almost like stitches and then covered them in JB weld, it has held per brilliantly so far, the super glue is just to position the "stitches" I don't think it adds much to the actual repair. That is the repair in effect in that video, I was nervous it would fail, even with good previous experiences with jbw but it held fine.

It really helps to rough up the surfaces you're fixing, gives the glue something to latch onto. And if you can, drill out the two parts and put a little bit of metal joining them like they do broken bones. If not or maybe even if you can, put some metal splits around the outside too and build up the adhesive, don't be afraid to add another layer, it might not look awesome but it will add strength. The 2 part epoxy glues don't have a whole lot of actual adhesion but they get incredibly hard when they set so if you give it something to grip on to it can be incredibly effective. 

[TheMidnight Pumpkin]

39 minutes ago, nowinaminute said:

I was going to suggest a 2 part adhesive. If that stuff doesn't work I HIGHLY recommened JB weld, it has been amazing in my experience. That Nikko Dictator with double brushless I posted on the previous page, it was a wreck when I got it, the gearbox case was cracked where the lower A arm attaches on the front gearbox, if you flexed it you could see inside the gearbox it was that bad. I cut a paper clip up into short lengths and uses some super glue to place the them along the crack on the inside of the gearbox almost like stitches and then covered them in JB weld, it has held per brilliantly so far, the super glue is just to position the "stitches" I don't think it adds much to the actual repair. That is the repair in effect in that video, I was nervous it would fail, even with good previous experiences with jbw but it held fine.

It really helps to rough up the surfaces you're fixing, gives the glue something to latch onto. And if you can, drill out the two parts and put a little bit of metal joining them like they do broken bones. If not or maybe even if you can, put some metal splits around the outside too and build up the adhesive, don't be afraid to add another layer, it might not look awesome but it will add strength. The 2 part epoxy glues don't have a whole lot of actual adhesion but they get incredibly hard when they set so if you give it something to grip on to it can be incredibly effective. 

I could not agree with this JB weld advise more!  In the glue world JB weld is like having a nuke in a BB gun fight. A little back explanation for the guys not in the US. In the old days of Ford brand cars (20's - 40's) they made flat head engines in the US. I don't know about your countries history. But flat head engines were known for over heating even with everything within factory spec. So cracked cylinder heads were common on those engines. I have seen guys literally JB weld those cylinder heads back together and drive them for thousands of miles trouble free. Its truly an amazing glue in the broad usage sense.

[smirk-racing]

On 8/15/2017 at 5:05 PM, Kingfisher said:

Well, this happened. 

 

 

My girlfriend and I were running the Pumpkin in the back yard. We (she) was going on a full speed run across the back yard, got too close to a lamp post, and caught it with front tire. We heard a loud snap, thought "that didn't sound good", and had a look. On first glance, we didn't notice anything wrong, and continued running the Pumpkin. It ran fine without any noticeable handling issues through the grass. When I was going to put the Pumpkin away, I noticed what looked like a fracture in the control arm. I spaced it apart for the first photo. Any chance I could glue this back together and it would be fine, or should I just replace it all together? What glue would you use? 

I do not blame Shapeways or Ampro for the break. I blame the lamp post for being in the way. 

Build, Bash, Break, Repeat, Right? 

Could you fit a sleeve around it, like a short piece of brass or aluminum tubing that is just a little larger in diameter than the arm? If so, with some good glue I think the resulting joint could be stronger than the surrounding material.

 

 

[graemevw]

Not sure if it will work on those arms, but this stuff is amazing.

www.plastex.net

 

Its a fine powder and a solvent. I use it for every plastic repair I do. You can rebuild entire sections of stuff as well as just glue things back together.

Ive just used it to delete the sunroof and roll bar holes on my blackfoot shell.

If you didnt have the sunroof panel you could even use this stuff to completely fill the sunroof hole.

 

Not cheap but seems to be lasting well, all depends how large a piece you need to make. For small holes, general cracks etc it goes quite far.

[Kingfisher]

13 hours ago, nowinaminute said:

 If that stuff doesn't work I HIGHLY recommened JB weld,

My plastic glue kit is either too old, or maybe I shouldn't have left it on a shelf in a hot garage for a year.  The glue itself was rock hard. I have some experience working with fiberglass for 1:1 automotive body work. I bet I could really strengthen that arm if I wrapped a small piece of fiberglass cloth around it, and set it with the resin.

12 hours ago, TheMidnight Pumpkin said:

I could not agree with this JB weld advise more!  In the glue world JB weld is like having a nuke in a BB gun fight. 

JB Weld is awesome stuff. I used it to fix a busted 1:1 car radiator once. 

 

9 hours ago, smirk-racing said:

Could you fit a sleeve around it, like a short piece of brass or aluminum tubing that is just a little larger in diameter than the arm? If so, with some good glue I think the resulting joint could be stronger than the surrounding material.

 

 

Good idea. I'll see if that's possible.

4 hours ago, graemevw said:

Not sure if it will work on those arms, but this stuff is amazing.

www.plastex.net

 

Its a fine powder and a solvent. I use it for every plastic repair I do. You can rebuild entire sections of stuff as well as just glue things back together.

Ive just used it to delete the sunroof and roll bar holes on my blackfoot shell.

If you didnt have the sunroof panel you could even use this stuff to completely fill the sunroof hole.

 

Not cheap but seems to be lasting well, all depends how large a piece you need to make. For small holes, general cracks etc it goes quite far.

I saw the work you did on the blackfoot shell. Nice job and thanks for the suggestion. Definitely something to consider.

[graemevw]

Took a few hours with a file to get the roof flat but just put the base on it. Waiting for it to flash off enough to clear it.

Ill put more pics up later.

 

I have tried sprue to sprue glueing with just the plastex fluid and it works well.

[Kingfisher]

She did it again. 

 

 

 

 

You can see my epoxy/fiberglass repair from her previous accident on the other control arm. She shattered this one.

 

I was across the parking lot in a patch of dirt when she came walking up carrying the Pumpkin. I asked what happened, and she said that she was trying to jump an angled parking curb that looks like this one:

 

 

 

I asked how fast she was going when she hit it, and her response was that her Lunchbox does it all of the time. She wouldn't tell me just how fast she was going, but I am willing to bet that she didn't hit it straight on, or ran into the side of it. 

So, next i'll be going back to the stock front suspension. For anybody that has the Futaba FX10 suspension, do those arms have some flex to them like the Tamiya arms, or do they snap like the 3D printed arms when a little force is applied? I really liked this suspension setup, and the handling improvement, but it's not up to the abuse that my girlfriend puts it through.

[Munchbox]

I don't have any first hand experience with the fx10 setup but I've heard it's just as tough as the stock setup. If I were going to go double wish bone up front I would definitely go fx10. 

I've heard that the Ampro parts are a much simpler setup because they bolt straight on but the fx10 parts need some working to get them just right. 

The way I abuse my Lunchbox I would have to go fx10. Ive already noticed stress bends in the stock A arms and I've only had the truck since last Christmas.