Baja Front Suspension Build #4 (Lower Control Arms)

In this video I finally get a design for the lower control arm that I like and seems like it will work. So in this video I go over some of the design and fabrication.

[@babybro66]

I just started watching this series about your suspension cause I'm building a gambler 500 rig and am making a halfway custom suspension. I think you said in the first video that you're not a pro youtuber but that you thought youd try to record your progress to help others. But honestly you provide more info than a majority of youtubers and dont add anything we dont need/want to watch. You're an absolutely wonderful teacher, blvery clear and straightforward about how and why certain aspects work with suspension and it's not a simple subject to teach, great job and thank you!

[@DougBugBuilder]

Thanks buddy! Very much appreciate the kind words. Good luck with your build.

[@blubb7711]

I´m building a 1/10 RC trophy truck, completly 3D printed and I really enjoy your videos.

[@DougBugBuilder]

That's awesome! A lot of the inspiration on this design came from an RC10.

[@bloodredhornet2704]

Top notch sir! Your channel has taught me a lot. I love how resourceful and thorough your work process is.

[@DougBugBuilder]

Thanks buddy, I'm glad you're taking something away from the videos. Thanks for the comment.

[@timothylewis4183]

@@DougBugBuilder many of us are really learning from your good work, 👌👍

[@DesertRatFabrication]

Wow Mike, really enjoyed the video, looks super strong, quality work, can't wait to see them fully Tig welded up

[@DougBugBuilder]

Thanks Mike!

[@agustinlugo778]

Algún día voy hacer un juguete así, no tengo la herramienta, pero no pierdo la esperanza de hacer uno, gracias por los videos que compartes y tu conocimiento, saludos!! Sin llorar..

[@DougBugBuilder]

No te preocupes por eso. Comience con poco y un día se dará cuenta de que tiene un montón de herramientas. Gracias por el comentario y buenas cosas para ti!

[@comandernehal8567]

We all have to admit you are an excellent mentor. I am a first timer in the Formula Student project & have zero knowledge about a basic car. But thanks to your videos. Its really helping me out to understand the basics. Best of luck with all of your projects brother...

[@DougBugBuilder]

Thanks for the kind words. 👍 Good luck with the student project, that sounds really cool.

[@lawrenceirvine8759]

You are like that AVE guy...you are just so god damn smart! I'd like to do a Vulcan Mind Meld!

[@DougBugBuilder]

If we Mind Meld then can I have you work on my Baja's? Since you would then know them inside and out. 😉✌

[@bigwadventures7061]

Lots of engineering going on for this project. Totally Jealous of your new Shop/Garage. I like watching you do all the buildings of your projects. Thanks for the update and sharing. BigW:-)

[@DougBugBuilder]

Thanks Big W!

[@SGTMARSHALL1]

Really enjoying your videos, surprised your control arms don't have better aerodynamics, I would have rotated the SHS closest to your spindle mount lugs on a 45 degree for improved clearance at max articulation and full droop. I possibly would have done the leading edge of the lower and upper arms in angle instead of flat and turned the trailing edge up to create downforce because it's available and everything adds up 😉🥃🚬 all the best from 🇭🇲

[@DougBugBuilder]

I would call those fine details, not disagreeing with you on any of it. But typically my initial designs are a little basic. Then if the design works you'll see me come back and make things a little better. Which would include some of the details you're talking about.

[@brettfoster6786]

Arm's Looks rock solid . dog did a nice job shaping your shim also .

[@DougBugBuilder]

Thanks, yeah my dog is a big help in the shop. (nope)...lol

[@IllusoryRedoubt]

That looks spotty dog mate 🤙 shredding in no time.

[@DougBugBuilder]

Yes sir! She'll be rippin here soon.

[@liljohnp132]

Damn good fab skills , excellent job.

[@DougBugBuilder]

Thanks buddy!

[@bear4380]

Another excellent video

[@DougBugBuilder]

Thanks Bear!

[@northpeak4x4]

If the bushing sleeves are 1.5" ID, Ruffstuff Specialties sells aluminum spacers made for mockup. For those of us that don't have a lathe anyway. I always enjoy your videos.

[@DougBugBuilder]

That would propably work.... but I do have a lathe. ;-) lol Thanks for the tip though. Might help others.

[@garykowalczyk7415]

Doug Bug nice set of video's. As an engineer I do the same thing but on cad. I made a quick 3d model of your lower arm, ran FEA will 2000 pounds of shock load and got very little deflection. Nice job!

[@DougBugBuilder]

That's really cool you did that. Thanks for the info, I am a little worried it would be to weak. But hearing that makes me feel a little more confident. 👍

[@dorsk84]

No! No! Not a chew toy...Fine! It's now a chew toy. -every dog owner.

[@DougBugBuilder]

Lol, yeah... pretty much how it goes.

[@jonathanmurray1863]

Your getting good at this

[@DougBugBuilder]

Thanks! 👍

[@jonathanmurray7831]

Four or five months ago I built a sand rail for my friend we both built it 16oo dual port can highpo man it was fast he sold it five grand. We paid cheap and built it up took about month

[@fredcocksamich7993]

Good to see you back !! I watch the video when I get home !!

[@jonathanmurray1863]

You could put holes in arm to place struts back and forth

[@ciobanuvalentinmail]

Hi, to me it looks much stronger then you need. What i learned from mine buggy construction, is that with the arms it's better to have a longer spring and the connection point to be next to the wheel, not to the midle of the arm... Anyway, carry on.😁

[@DougBugBuilder]

I can't argue with that. I'm not to concerned with it on the front. But for the rear I'll consider getting 16" shocks so the shock can be out like you're saying. Thanks for the comment.

[@dorsk84]

You do have some experience with R/C like I do. I would have toyed with the idea of an inline suspension like on the Traxxas REVO or F1 cars. Smaller shocks, you can run steering on the rear of the knuckles without interference, and adjustable progression rates with out the need to disassemble the shock.

[@DougBugBuilder]

@@dorsk84 Yes! I have a Revo! I know just what you're talking about. That would be cool.

[@sandboundchris]

Did you ever think about using heim joints to mount the lower arm to the frame?

[@shaanahiranandani44]

hi i know i am replying to a 4 year old video but could you tell me how did you mount the spindle point to the knuckle, it would be really helpful as i too am a car enthusiast just as you , and i will be making my own baja buggy. Thank you

[@chaddsnoddy2390]

Hey what size heim joints are you using for your steering? Awesome build!! Thanks

[@DougBugBuilder]

They are 3/4", this is where I got them. www.kartek.com/parts/fk-rod-ends-34-right-hand-thread-34-hole-kmx12-nylon-coated-heim-joints.html

[@slv4421]

Arm's Looks solid and well designed, are you also revisiting your rear suspension ? why a arm vs trailing arms ? any thoughts thanks ! good job man

[@DougBugBuilder]

Thanks Bud! I will be redoing the rear as well. Personally I really like the benefits of A Arm over trailing arm. I know there are some benefits to trailing arm, Simpler, stronger, easier shock placement, I'm sure there are other benefits. But A Arms have lots of benefits, and the biggest is that when A Arms travel if done right there really is no plunge for the axles. As they travel in the same plane as the A Arms. I could go on and on about this. But mainly I enjoy working with A Arms.

[@Youtubeforcedmetochangemyname]

Looks good nice a stout with no weight up front really I don't foresee any problems with that setup I could be wrong but I've been to many off-road races with a team and I've seen alot of rear engine cars have the shocks this way with zero problems will be interesting to see it work in the real world though can't wait to start my own build I'm actually considering getting a little Toyota or the like and turning it into a buggy just to be different since I haven't got a final decision on the car yet however I did just get a Hyundai given to me that might work well ill have to ditch front wheel drive though

[@DougBugBuilder]

I'm not to worried about it, but like you said we'll once I get to actually beat on it. I hope you can get a project going soon!

[@Youtubeforcedmetochangemyname]

@@DougBugBuilder so do I still in the process of moving from California to Arizona but as soon as I'm fully moved I will start something just didn't want to have to move with more extra stuff

[@rgn2222]

I've just started watching your videos, on this build, and I am gaining a lot of knowledge... Thanks. I have a question... There's is probably a good reason, I just don't know it. Why not use rear steering, like the standard VW beam suspension? The rack and tie rods would be more protected, and the Ackerman rule could be achieved correctly.

[@DougBugBuilder]

Because of the location of the shock absorbers on A Arm setup in order to have rear steering the steering rack would need to be mounteed really far back. This would cause issues with the steering shaft going from the steering wheel to the rack. Hope that makes sense.

[@ericmuhlbeier8023]

One would have to locate the shocks pretty far forward to rear steer on a setup like this...I agree on a reAr engine light rig it’s not as important

[@MrDesparza]

what bushing did you use for your spindle on the top and bottom? link to order some if you have it would be awesome!

[@DougBugBuilder]

Sure thing.... They are uniballs, this is them from KarTek. www.kartek.com/parts/fk-rod-ends-34-id-1-38-od-wssx12t-ptfe-coated-uniball-spherical-bearings-f2-fit.html You need the uniball, cup, misalingment spacers, and C clip.

[@kthschsslr]

Two questions: Why not a truss rod or truss shape instead of a consistent width? Why does no one use tapered roller bearings instead of bushings at A-arm pivot points?

[@ChrisCarter-ys2hs]

What size tires are you running on this front suspension? At "full bump" how high would the center of your frame be from the ground? Can it use all the up travel?

[@DougBugBuilder]

33" tires on the front. At full bump the chassis is 2.5" off the ground. But that's seeming to be a little short, maybe shoot for 3". The tires squish more than I expected. My suspension can go up more, quite a bit more before anything binds. But that doesn't do any good if the chassis hits the ground.

[@theshed1168]

Weld some tube around the spindle bolt if your worried about strength

[@DougBugBuilder]

Thanks for the tip.

[@guncalinhosiqueira8547]

It's show ! 👍👏🙋

[@DougBugBuilder]

Thanks buddy!

[@IllMakeItWork]

The lower knuckle tabs that you added to for strength. Just thinking, you could triangulate plate them in, above and below the bolt tab to really add strength to those tabs and can still easily put a bolt in. Just make it part of your top and bottom plate. 🤷🏻‍♂️ just a observation.

[@DougBugBuilder]

I agree there is a little more room there to add more material. But I'm thinking what I have here will be strong enough. But if I find that it's not I'll likely add some material where you are describing. Thanks for the idea.

[@jaytee1086]

Just a heads up. On this side of the camera it was hard to tell if there was enough room between the shock and chassis rail once the spring goes on. Nice work though, you got skills.

[@DougBugBuilder]

I know what you're talking about. It is close, very close, but there should be room. But either way I think that bar will need to be moved some to clear the upper control arm. Thanks for paying close attention and the comment! Appreciate it.

[@jaytee1086]

@@DougBugBuilder Maybe nothing more than a ball ping hammer and a torch can't fix. But then you'll need to gusset the anealment with a half tubing gusset.

[@wonderbread7503]

What’s the name of the tool you used to bend the 1-1/2 strips of steel??

[@DougBugBuilder]

I think they just call it a flat stock bender. This is the one I used. It's actually really handy. amzn.to/3FUdvge

[@CurtisDavis89]

Any chance that you could offer pdf file for the control arms, and label where and how far the bends are on the pdf?

[@DougBugBuilder]

Sorry, at this point I don't have drawings for the control arms.

[@TACOMASRT5]

I dont know much about building custom arms but I am undertaking a project for the norra 1000. Love your videos and I'd love to chat if you've got a chance

[@DougBugBuilder]

You can email me at [e-mail] if you want to chat. Or reach out to me on Instagram "Dougbugbuilder"

[@Youtubeforcedmetochangemyname]

But he really liked the stick lol

[@arrindaley3714]

I've been learning about suspension but not in an off road buggy context, but it seems the off road world doesn't seem to consider roll centres or roll axis, it would seem to me that with long travels and a high centre of gravity there'd be a lot to gain by raising the roll centre height to lessen roll, of course there is a downside to a high roll centre; jacking but I think it deserves some thought especially if your doing a A arm suspension and it can more easily be changed. An inclined roll axis can also positively effect handling feel. Do you have any idea why off road stuff doesn't seem to consider roll centres much? I can understand that camber gain or loss (another result of varying roll centre/virtual centres) is unlikely to be as important in an off road context. Btw parallel A arms or a trailing arm will put the roll centre at ground level.

[@DougBugBuilder]

Arrin, I think for the most part it's not considered in these vehicles because it would take away from some travel and these vehicles basically go in a straight line. If I was designing this for short course I would give up some travel and pay some attention to the roll cneter. But with most of the driving this buggy will see I want travel more than anything. That's why this setup doesn't have much camber change at full droop. If it did I'd lost travel as the steering would bind faster.

[@arrindaley3714]

@@DougBugBuilder I guess I never thought it might limit travel in a double A arm (front and rear or just front with steering arms?). The car I am playing with is a classic Morris Mini, so a couple of inches of travel total. For the rear there's semi trailing arms, I can't see they would have any effect on travel and given most of your weight is in the back and the rear roll centre wants to be higher than the front it could be an idea? Just don't do it using deflecting rubber bushes like Porsche did. I've a spreadsheet I've made to calculate the effect on camber and toe (in), I'd be happy to send it to you if you're interested. Rear wheel drive track cars typically don't like the camber change on squat but I figure that doesn't bother off roaders much.

[@DougBugBuilder]

@@arrindaley3714 I could possibly consider it in the rear. That's limited already by driveshaft angles. If you don't mind send me your spreadsheet, I'd like to see the deflection. My email is [e-mail] Thanks.

[@tranjavanadbia123]

Is it hollow or is there wood inside ?

[@DougBugBuilder]

It's hollow, the wood is only there while I'm tacking it all together.

[@tranjavanadbia123]

@@DougBugBuilder ok cool

[@vipnews5858]

Hi 👍 great job but this lower arm week from three side I think so if I hurt you sorry for that

[@Youtubeforcedmetochangemyname]

Why do you claim this looks strong if you could elaberate

[@alexsevilla2817]

Shuuuuu no Hable tanto amigo. Terrible El video

[@exportedafrican]

Argh. I hate that shock mounting location. Looking at the arm without measurements 50% of your spring forces will push on the chassis mount and the other 50% on the wheel. So a 100lb spring gets you 50lb of spring rate at the wheel. This will wear out your shocks 4x faster and cause additional stress on the frame. If possible- get a shaft extension and move it closer to the wheel or extend the chassis upper mount for the shock outwards. I know that isn’t always easy.

[@DougBugBuilder]

Wow dude...... no need to hate. ;-) Think about it. With still using a 12" shock and still getting 22" travel there is no way to lessen the forces on the shock. No matter how I position it the shock is still basically moving half of the control arms movement. An extension won't work because it will reduce travel. The only thing I can do is get a longer shock absorber, reduce my travel, or use linkage with a cantilever. Personally I think on the front of the chassis here it will be ok. But who knows, it won't be the first part I make that fails. ;-) Thanks for the comment though, it keeps us all thinking.

[@pauldavis437]

Hi i am back.

[@DougBugBuilder]

Welcome back! ;-)