Yeti.Stealths Ascenders

[Natedog]

I haven't broken any screws like that, the plastic upper links mount has gotten bent on my Blazer. I would carefully cut around the broken screw with sharp knife at the outer most stepped part of the axle housing, cutting off the last 3mm or so, then unscrew the ring of plastic that you just cut free of the axle housing. Clamp visegrips onto broken screw and unscrew it, drill both upper link mount holes rest of way into housing, then re-attach the upper links mount using two 4-40x9/16" screws. I would drill the holes all the way into and through Ernie's brass tubes, use 4-40 tap on the holes before screwing it all back together with longer screws. Fyi stock screws there are 2.8x10mm, just ensure the replacementes aren't too long and hit inner axle shafts.

I'm working on another idea to reinforce the upper links mount.

Ernie, very generous of you!

Edit, if you didn't have brass tubes, I wouldn't tap the holes, let the screws make their own threads in the holes. Might not go longer with your setup, easy to end up with no threads and a loose holes if you don't tap just right when transitioning from plastic to brass.

[CODYBOY]

Nates fix will work, if you can get the broken screw out. The upper link mount screws bottom out on the brass inserts. I use a 3/32" drill bit for the 3mm tap. If you guys think it would help in strengthening that area I could start doing that to my axles, that way the brass is your anchor instead of the housing.
But my offer still stands on the replacement.
Ernie

[Natedog]

Thanks Ernie. Edited my last post here for proper screw size.

Aaaand edit again!

2.8x10mm

[Yeti.stealth]

Thanks Ernie! Fantastic offer for sure, please PM me the details mate!

Am I the only one breaking the link riser screws?

I hope I can save this axle, if not I will have a go at reverse engineering it Ernie, and refit the brass tubes into a new axle housing.

The plan to fix it is to make a sheet metal bracket that attaches to the lower link screw and upper link screw, also thinking about drilling through upper link riser and into spool housing, put a 3mm screw in it, looks like enough room inside to take a 3 mm nut and not touch the spool. That should bolt it all down and take load off the 1 screw that's holding it now.

[Natedog]

You won't get the tubes out without destroying everything, they're really in there, Ernie built them strong. Looking forward to your upper link fix, sounds similar to mine. I was thinking L bracket from upper link mounts to top of axle housing, with washer inside housings using 2.5 or 3mm button head from inside the housings. Maybe two 2mm buttonheads instead, we'll see. That's why I bought STRC aluminum upper link mounts for front and rear of both trucks.

I haven't broken those screws yet, anybody else?

[Natedog]

Building my axles upper link mount braces and the two stock screws are 2.8x10mm!

Holes in axle are 11mm deep and do not penetrate to inside of axle tubes.

Stock screws get about 7mm thread engaging the plastic axle housing.

A 15mm long screw would just bottom with upper link mount in position, therefore I would drill the holes through just to inside of housing and use 15mm long screws. This will clear the spool bearing and axle shaft.

Inside of link mount pockets where screw heads seat are 0.184" ID, stock 2.8x11mm screw heads are 0.176 OD, 3mm socket head cap screws I have are 0.212" OD, therefore step up to 3mm is not big jump but requires drilling upper mount link screw head pockets accordingly to fit screw heads. I would keep them close fitting as possible because they help support the mount.

The 2.8mm screws have a course thread to bight into the plastic housing better than finer pitch of 2.5mm and 3mm machine screws. The coarser thread looks very similar to 4-40.

Underside of 2.8mm screw heads are also serrated to help prevent loosening.

Measured couple 4-40 socket head cap screws. Thread OD is just under 0.110", pitch is nearly identical ti 2.8mm screws, head OD ranges from 0.178" to 0.183". All three 4-40 screws I measured fit into the stock plastic upper and STRC aluminum upper link mounts.

There's room inside axle housing for a 3mm nut or screw head and flat washer.

[Yeti.stealth]

Thanks Natedog, a lot of info there!

Had a go at making a bracket, but the geometry is wrong☹️ The bracket seems to do zip with regard to taking the axle roll load off the riser mount screws, it just pivots on the 2 screws, the bracket needs a 3rd screw in it somewhere to stop it all rotating...

[Yeti.stealth]

Drilled right through link riser and into spool housing, took a wild guess at where to drill and what angle looked about right and fitted a 3 mm screw with a ground down nut. Also made a tiny little spacer to fit between link riser and housing. Fiddly work indeed!

This has anchored everything down now and should work as a fix for my Broken screw, hopefully saving my weighted rear axle.

[Yeti.stealth]

Nut inside spool housing, clears the spool no problems

[CODYBOY]

Originally Posted by Yeti.stealth

Nut inside spool housing, clears the spool no problems

Attachment 357208

Nice job by both you guys of researching a fix to a problem!!! Isn't DIY fun on these little trucks.
Ernie

[Natedog]

X2, very nice Yeti.stealth! FYI there should only be about a 3mm flat washer worth of space between a new un-used rear axle upper link mount and the axle pumpkin. I've found that the stock plastic link mount does get bent forward after not a lot of run time. STRC upper link mounts are pretty nice and fit well, worth the $13.99 each I paid.

RPP Hobby | Radio Controlled Cars, Trucks, Boats, Helis, Planes, Plastic Models

Black anodized rear:
https://www.rpphobby.com/product_p/sptstv232074rbk.htm

Gun metal grey rear:
https://www.rpphobby.com/product_p/sptstv232074rgm.htm

Silver rear:
https://www.rpphobby.com/product_p/sptstv232074rs.htm


Black front upper link mount:
https://www.rpphobby.com/product_p/sptstv232074fbk.htm

Gun metal grey front:
https://www.rpphobby.com/product_p/sptstv232074fgm.htm

Silver front:
https://www.rpphobby.com/product_p/sptstv232074fs.htm

[rockhugger]

Originally Posted by Yeti.stealth

Thanks Natedog, a lot of info there!

Had a go at making a bracket, but the geometry is wrong☹️ The bracket seems to do zip with regard to taking the axle roll load off the riser mount screws, it just pivots on the 2 screws, the bracket needs a 3rd screw in it somewhere to stop it all rotating...

Attachment 357206

Originally Posted by Yeti.stealth

Drilled right through link riser and into spool housing, took a wild guess at where to drill and what angle looked about right and fitted a 3 mm screw with a ground down nut. Also made a tiny little spacer to fit between link riser and housing. Fiddly work indeed!

This has anchored everything down now and should work as a fix for my Broken screw, hopefully saving my weighted rear axle.

Attachment 357207

Originally Posted by CODYBOY

Nice job by both you guys of researching a fix to a problem!!! Isn't DIY fun on these little trucks.
Ernie

X2 - agreed... good job both of you!!! That little bracket has a lot potential. I see a greater purpose there in becoming an upper link mount and truss by way of origami (to use the term Duuuuuuuuude used in his 6x6 build). Keep up the good works.

[JatoTheRipper]

Some clever ideas in this thread! Nice!

[CODYBOY]

Here is another good reason to have some Codyboy axles. Been talking with Nate about this so thought I would throw out my Idea.



So with the stock axle upper link mounts we are getting a lot of flex so a few of us have been working on a fix.
I drilled through the link mount holes into my brass tubes and tapped them for 4-40 screws.



I pulled and tried to get the link mount to flex and it didn't move.



Any one else have beside Nate and Yeti have any thoughts on this?
Ernie

[Natedog]

Here's the Tamiya TLT link bracket I used for my brace. Was ready to drill housing and mount, but it felt and looked kinda wimpy once it was all done. Ernie, Rockhugger and I all like Yeti.stealth idea better, so that's what I'm doing. Drilled my housing, attached STRC aluminum link mount with two 4-40x5/8" cap head screws, didn't drill the brace screw hole yet since it was late and I was tired. "mrgreen"

As Ernie asked, please provide input guys and gals, thanks!

[Yeti.stealth]

I like your bracket Natedog, can't believe it wouldn't be strong enough. If you drill through into the housing like I have, you will have to mess around making a funny shaped spacer to go between housing and link riser, it was fiddly work. Drilling a hole for your bracket would be very easy and accurate every time, and no funny shaped spacer.

Seeing your bracket now has given me an idea.

Ernie,
Nice work on beefing up those axles, I assume the 4-40 screws are a bit larger than stock screws, maybe a bit tougher to snap one of those off?

[Natedog]

Thanks, easier to drill straight down for sure , but need to shave about 0.035" off middle ear to make room for the bracket. I think yours is stronger and we're hard on parts.

Good, look forward to see what you change next.

4-40 screws are almost exactly same size and thread as factory and hard to find 2.8mm screws.

Edit, I'm going with 2.5mm screws, flat washer and nut on mine. Start small on drill size (but not so small it flexes and wanders) and aim well lol.

[Natedog]

Very nice 3d cereal box printing!

[rockhugger]

I borrowed Yeti.Stealths bracket idea and repurposed it to this CNC'd CAD truss. I then 3D printed it on my cardboard printer. I hope you dont mind my using your bracket idea.

Having trouble posting correct size pics.

[rockhugger]

This would allow multiple link locations at the axle and stiffen the flexible parts all in one.