RCCrawler Forums

brainleak · 08-04-2011, 09:25 AM

I am currently building my PD chassis and I'm almost complete. (I'm guessing about a week out. expect a lot of pics once I've completed) I need to fabricate upper links. I've seen a lot of build threads with people using delrin rod. What kind of diameter are we talking about for the rod? Any recommendations on a site to purchase it from?

DRV KRAWLER · 08-04-2011, 09:46 AM

I used the 5/16" Delrin on my "PD".

Buy from Mcmaster-carr best price.

"The official Tuolumne County Poison Dart"

brainleak · 08-04-2011, 10:39 AM

Mcmaster is really cheap. Thanks for the pointer.

paul6ppca · 08-04-2011, 10:41 AM

I got mine thru amazon,free shipping when I got a few cds.

Stormin2u · 08-04-2011, 10:54 AM

I use 1/4" on uppers.

Dasher · 08-06-2011, 08:59 AM

I've made up both 6mm and 8mm diameter links but haven't decided which to use yet. The reason I've made up both is to trial both 3mm and 4mm ends. If I'm not mistaken, Casey uses the 3mm ends on the upper links and therefore the 6mm rod should be OK. Putting a 4mm set screw into 6mm rod just seemed a little risky to me.

There are other considerations. 6mm links take up noticably less space, but they definitely flex more. So, if you favour running long links then maybe you should consider the wider diameter rod.

sim · 08-07-2011, 09:38 PM

6mm Delrin isn't stiff enough in most lengths. 8mm is okay but still floppy on longer lengths. I personally think aluminium is a better material for upper links as you can get the required stiffness using just 6mm rod, and it's lighter (and stiffer) than 8mm delrin. I mostly worry about stiffness since strength and impact resistance isn't an issue for upper links. Delrin is easier to drill and tap though.

Edit: 25.4mm = 1 inch.

kmnss · 08-07-2011, 09:57 PM

Use aluminum at least. Delrin uppers flex horribly.

Dasher · 08-08-2011, 09:45 AM

Although I've tested both 6mm and 8mm Delrin for the uppers, I'm actually using RC4WD solid aluminium links. My links are not very long and my main reason for testing was to go look at options for going to 4mm ends. If I do go 4mm, and that's a real possibility on the PD, then I'll also use 4mm long ends. This will keep the actual link quite short and at the same time will give me a little more clearance where I need it.

I don't seem to have a problem with 3mm ends on the upper links, but on the lowers of course, the difference is like night and day.

gunnar · 08-08-2011, 10:03 AM

Took a bit of work to make them, but I like to use 3/16" 7075 rod for uppers. 1/4" delrin will work for short uppers with 3mm setscrews, 5/16" is better with a 4mm screw, but to reduce flex with delrin, I wouldn't make the link any longer than about 60mm in 1/4".

Pic of a Lunsford Ti link above the turned-down 7075 stuff, ready for threadiing:

no1970ax1o · 08-08-2011, 12:46 PM

I used jato steering links they'er adjustable

Dasher · 08-08-2011, 12:54 PM

Now they are nice!
I'm only just mastering tapping delrin, so Ti is a long way off!

I find the RC4WD links work well, it's just that for the PD I want to ability to custom fit the lengths and that means making my own - delrin is about the only stuff I feel confident working with. I will take your advice though Gunnar and stick to the wider diameter and 4mm ends. The long ends enable me to keep the actual delrin part of the link reasonably short.

gunnar · 08-08-2011, 01:31 PM

The shorter Revo ends are marginally stronger than the long Jato's(in the tapered area between the ball and the barrel), but the Jato's are good for small adjustments by trimming them down instead of the actual links when in the field.

The way I made 5/16" delrin links was this: Get a JeepinDougs drill guide, drill the center out to 1/8" which will be fine for a 4mm tapping hole.
The distance from the center hole in the ball to the end of the rodend for a Revo is 17mm, so your link should be 34mm shorter than the actual eye to eye measurement. Hole in the link should be 10-12mm deep.
M4X20 setscrew is threaded into the rodend first, then tap about 3-4 threads in the delrin. If you tap the hole all the way into the delrin, the joint can get sloppy and weak over time. You can thread in the setscrew without tapping the link, but this will stress the rodend as you are turning it. Thread the rodends in, and your done.

The Lunsford link was arleady tapped, but I have shortened them too, they are difficult to narrow down, but tapping the threads was not too bad.
The aluminium is easy work with, light, and quite strong, almost as strong as the Ti if 7075 alloy is used.

Manning · 08-08-2011, 06:16 PM

I've used 1/4" delrin for upper links, steering tie rods and drag links, and 5/16" delrin lowers with good results. As long as they are straight, it'll work fine.

Jato steering links work too.

brainleak · 08-09-2011, 01:21 PM

Thanks for all the Ideas, I'm thinking turnbuckles might be a good solution it would allow for a lot of adjustment. I might have some around that length I can cannibalize from an RC10GT chassis I have laying around.

Stormin2u · 08-18-2011, 11:48 AM

Quote:

Originally Posted by kmnss

Use aluminum at least. Delrin uppers flex horribly.

I do get a little flex using 1/4" Delrin but it's not really a bad thing at all my comp results prove it, and my shafty weighs in at 5.5 #s which is a super good thing for over all performance. Stiffness is way over rated IMO more isn't always better.

mayheem · 08-27-2011, 02:15 PM

do you guys have part numbers for the jato steering links

Dasher · 08-27-2011, 03:20 PM

Quote:

Originally Posted by mayheem

do you guys have part numbers for the jato steering links

The Traxxas ones that I use are #5347 and #5525. I'm not that familiar with Traxxas Vehicles but I think that the 5525 are Jato and 5347 the Revo. It doesn't really matter as it's worth having a stock of both - the difference is a few mm in length and having a choice of length can be useful in tuning the uppers. They're sold in packs of 12 and cost about $10 a pack.

Jstall7543 · 08-29-2011, 06:43 PM

I've been busting a traxxas link almost every time out, I personally don't recommend them. My buddy's all use axial and they never brake. If you do use them then carry extras and the tools required to change em. The plastic is to hard and just snaps off clean. If it gets to bound up I just pick it up and I'm still braking them. I just switched back to all axial ends last night.

superzuki1986 · 11-03-2011, 01:38 PM

Are you using standard Traxxas rod ends? the Revolt and Jato ends are both much stronger than the small standard ones.

08-04-2011, 09:25 AM	#1
brainleak Newbie Join Date: Jun 2011 Location: USA Posts: 14	Delrin rod upper links I am currently building my PD chassis and I'm almost complete. (I'm guessing about a week out. expect a lot of pics once I've completed) I need to fabricate upper links. I've seen a lot of build threads with people using delrin rod. What kind of diameter are we talking about for the rod? Any recommendations on a site to purchase it from?

08-04-2011, 09:46 AM	#2
DRV KRAWLER RCC Addict Join Date: Dec 2008 Location: Sonora, CA Posts: 1,664	I used the 5/16" Delrin on my "PD". Buy from Mcmaster-carr best price. "The official Tuolumne County Poison Dart" Last edited by DRV KRAWLER; 08-04-2011 at 09:47 AM. Reason: added info

08-07-2011, 09:38 PM	#7
sim Quarry Creeper Join Date: Apr 2005 Location: Malaysia Posts: 374	6mm Delrin isn't stiff enough in most lengths. 8mm is okay but still floppy on longer lengths. I personally think aluminium is a better material for upper links as you can get the required stiffness using just 6mm rod, and it's lighter (and stiffer) than 8mm delrin. I mostly worry about stiffness since strength and impact resistance isn't an issue for upper links. Delrin is easier to drill and tap though. Edit: 25.4mm = 1 inch. Last edited by sim; 08-07-2011 at 09:40 PM.

08-08-2011, 01:31 PM	#13
gunnar Ex Nor-CalRCRC slave Join Date: Dec 2008 Location: San Mateo, CA. Posts: 2,242	The shorter Revo ends are marginally stronger than the long Jato's(in the tapered area between the ball and the barrel), but the Jato's are good for small adjustments by trimming them down instead of the actual links when in the field. The way I made 5/16" delrin links was this: Get a JeepinDougs drill guide, drill the center out to 1/8" which will be fine for a 4mm tapping hole. The distance from the center hole in the ball to the end of the rodend for a Revo is 17mm, so your link should be 34mm shorter than the actual eye to eye measurement. Hole in the link should be 10-12mm deep. M4X20 setscrew is threaded into the rodend first, then tap about 3-4 threads in the delrin. If you tap the hole all the way into the delrin, the joint can get sloppy and weak over time. You can thread in the setscrew without tapping the link, but this will stress the rodend as you are turning it. Thread the rodends in, and your done. The Lunsford link was arleady tapped, but I have shortened them too, they are difficult to narrow down, but tapping the threads was not too bad. The aluminium is easy work with, light, and quite strong, almost as strong as the Ti if 7075 alloy is used. Last edited by gunnar; 08-08-2011 at 01:36 PM.

11-03-2011, 01:38 PM	#20
superzuki1986 Rock Stacker Join Date: Jul 2007 Location: Maryville, TN Posts: 66	rod ends Are you using standard Traxxas rod ends? the Revolt and Jato ends are both much stronger than the small standard ones.

08-04-2011, 10:39 AM	#3
brainleak Newbie Join Date: Jun 2011 Location: USA Posts: 14	Mcmaster is really cheap. Thanks for the pointer.

08-04-2011, 10:41 AM	#4
paul6ppca Rock Stacker Join Date: Mar 2011 Location: RI Posts: 69	I got mine thru amazon,free shipping when I got a few cds.

08-04-2011, 10:54 AM	#5
Stormin2u I wanna be Dave Join Date: May 2007 Location: Taylors Falls just hanging with the MNRCRC crew. Posts: 7,843	I use 1/4" on uppers.

08-06-2011, 08:59 AM	#6
Dasher Croakin' across the pond! Join Date: Jan 2011 Location: Nottingham, UK Posts: 272	I've made up both 6mm and 8mm diameter links but haven't decided which to use yet. The reason I've made up both is to trial both 3mm and 4mm ends. If I'm not mistaken, Casey uses the 3mm ends on the upper links and therefore the 6mm rod should be OK. Putting a 4mm set screw into 6mm rod just seemed a little risky to me. There are other considerations. 6mm links take up noticably less space, but they definitely flex more. So, if you favour running long links then maybe you should consider the wider diameter rod.

08-07-2011, 09:57 PM	#8
kmnss Rock Crawler Join Date: Jun 2007 Location: Arlington Posts: 684	Use aluminum at least. Delrin uppers flex horribly.

08-08-2011, 09:45 AM	#9
Dasher Croakin' across the pond! Join Date: Jan 2011 Location: Nottingham, UK Posts: 272	Although I've tested both 6mm and 8mm Delrin for the uppers, I'm actually using RC4WD solid aluminium links. My links are not very long and my main reason for testing was to go look at options for going to 4mm ends. If I do go 4mm, and that's a real possibility on the PD, then I'll also use 4mm long ends. This will keep the actual link quite short and at the same time will give me a little more clearance where I need it. I don't seem to have a problem with 3mm ends on the upper links, but on the lowers of course, the difference is like night and day.

08-08-2011, 10:03 AM	#10
gunnar Ex Nor-CalRCRC slave Join Date: Dec 2008 Location: San Mateo, CA. Posts: 2,242	Took a bit of work to make them, but I like to use 3/16" 7075 rod for uppers. 1/4" delrin will work for short uppers with 3mm setscrews, 5/16" is better with a 4mm screw, but to reduce flex with delrin, I wouldn't make the link any longer than about 60mm in 1/4". Pic of a Lunsford Ti link above the turned-down 7075 stuff, ready for threadiing:

08-08-2011, 12:46 PM	#11
no1970ax1o Pebble Pounder Join Date: Nov 2010 Location: flagstaff Posts: 114	I used jato steering links they'er adjustable

08-08-2011, 12:54 PM	#12
Dasher Croakin' across the pond! Join Date: Jan 2011 Location: Nottingham, UK Posts: 272	Now they are nice! I'm only just mastering tapping delrin, so Ti is a long way off! I find the RC4WD links work well, it's just that for the PD I want to ability to custom fit the lengths and that means making my own - delrin is about the only stuff I feel confident working with. I will take your advice though Gunnar and stick to the wider diameter and 4mm ends. The long ends enable me to keep the actual delrin part of the link reasonably short.

08-08-2011, 06:16 PM	#14
Manning RCC Addict Join Date: Nov 2006 Location: Lowell, Arkansas Posts: 1,307	I've used 1/4" delrin for upper links, steering tie rods and drag links, and 5/16" delrin lowers with good results. As long as they are straight, it'll work fine. Jato steering links work too.

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08-09-2011, 01:21 PM	#15
brainleak Newbie Join Date: Jun 2011 Location: USA Posts: 14	Thanks for all the Ideas, I'm thinking turnbuckles might be a good solution it would allow for a lot of adjustment. I might have some around that length I can cannibalize from an RC10GT chassis I have laying around.

08-27-2011, 02:15 PM	#17
mayheem Rock Stacker Join Date: Aug 2011 Location: murrieta Posts: 50	do you guys have part numbers for the jato steering links

08-29-2011, 06:43 PM	#19
Jstall7543 Pebble Pounder Join Date: Jan 2009 Location: Olympia Posts: 102	I've been busting a traxxas link almost every time out, I personally don't recommend them. My buddy's all use axial and they never brake. If you do use them then carry extras and the tools required to change em. The plastic is to hard and just snaps off clean. If it gets to bound up I just pick it up and I'm still braking them. I just switched back to all axial ends last night.

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Thread: Delrin rod upper links