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View Full Version : making your own a arms?



LilDacktyle
06-09-2004, 04:29 PM
i been looking around for arms for my banshee and i started to wounder, how hard it would be to make my own. has anyone ever done this and if they have, was it hard and do you have any pictures of them. thanks a lot.

300XFST4602
06-09-2004, 04:35 PM
:confused:

Pvt. Maggot
06-09-2004, 04:37 PM
you'd be better off buying them it would be alot safer...but..if the welder is a pro and such i guess it could be done safely.

LilDacktyle
06-09-2004, 06:43 PM
i was thinkin about saving up like $800 and still making them, so if they do break, i could just go out and buy some. but i mean if they work then thats $800 that i could spend on other stuff. anyone else?

boogiechile
06-09-2004, 06:45 PM
I make my own a arms, swing arms, steering stems, tie rods, and modify my frames. I do not recomend you do this unless you are skilled in more than metal fab. The design and engeneering to get a perfect setup is much more than the fab work if you are doing extended ones. However, I would give you some pointers and advice if you want to try it. I make my stuff for mojaves that I race in the 300 or 350 cc 4 strk class. Check out the stuff I make at the site below. look in my super mojave album for my newest a arms and stuff.

http://www.picturetrail.com/mojaveaddict

LilDacktyle
06-09-2004, 07:13 PM
WOW! Thats pretty sick. have you ever made some arms for a banshee or any other quads? well, now that i saw yours, i think im goin to give it a try. but first i need to get metal and stuff. i was wondering, what size tubing to get and what kind to use. but if i make +3's, im goin to need to get shocks right. i cant run stock with them right? and if i do make +3's would it be better to run 19 inch shcoks? well, i wount ask any more questions until i start to get closer to makeing them. but if you could help me out i would really apreciate it. thanks

dementedyouth55
06-09-2004, 10:26 PM
Its a bad idea. it doesnt sound like you know much about welding and such. But hey your dex so go ahead

LilDacktyle
06-09-2004, 10:32 PM
hey cody, your gay!

dementedyouth55
06-09-2004, 10:34 PM
Hey your moms over here! hehehehe

06-10-2004, 07:59 AM
What do you use to bend your tubing? Thanks

boogiechile
06-10-2004, 08:11 AM
Originally posted by ab****
What do you use to bend your tubing? Thanks

conduit bender and a little heat. Always let chromoly tubing cool on its own though, never cool with water or anything. Its a crude way but it is all I have and it works.

boogiechile
06-10-2004, 08:37 AM
Originally posted by LilDacktyle
WOW! Thats pretty sick. have you ever made some arms for a banshee or any other quads? well, now that i saw yours, i think im goin to give it a try. but first i need to get metal and stuff. i was wondering, what size tubing to get and what kind to use. but if i make +3's, im goin to need to get shocks right. i cant run stock with them right? and if i do make +3's would it be better to run 19 inch shcoks? well, i wount ask any more questions until i start to get closer to makeing them. but if you could help me out i would really apreciate it. thanks

Please don't take this wrong, but with the questions you are asking I think you may be in over your head making your own arms.

I will answer some of your questions though. I have never made banshee stuff, I only make mojave parts at this time. However there is really no difference, the process is the same no matter what quad. I use 4130 chromoly tubing. you can use various sizing and I do not always use the same size but my choice is 1 inch for bottom arms and 7/8 for top. I also use thinner wall tubing than most builders to save weight. I have not had a problem with strength. Most aftermarket companies overbuild here to make sure it is hard to bend. I use .083 wall on bottom and .083 0r .065 on top. A lot of arms are built with .125 on the bottom. When I want more strength I move up to a 1 1/8 inch bottom and stay at .083 wall.

It would be best to use the longer shocks with +3 arms. I would forget about the stock shocks. Here is the area that concerns me. It is obvious that you have little knowledge of suspension geometry and when you go changing length arms and shocks you have to consider many things when you build. like motion ratios, proper frame height at shock compressed length, caster, camber, camber gain through travel, + forward or not and how much, the ever critical angle of the ball joints in relation to the arm (this will change dramatically as the arm gets longer and will cause joint bind if not right), and etc etc.

It is not easy to build good arms and you just cant extend the stockers and leave everything else on them like it is. If you do, your frame will dig in the dirt on landings even with the right springs and valving in the shocks.

LilDacktyle
06-11-2004, 12:09 AM
thanks a lot for all the help. i was wondering, where do you get the ball joints or whatever, and how much are they?

boogiechile
06-11-2004, 08:57 AM
Originally posted by LilDacktyle
thanks a lot for all the help. i was wondering, where do you get the ball joints or whatever, and how much are they?


I buy them here. prices are listed.
http://www.aedmotorsport.com/FK/index.html

LilDacktyle
06-11-2004, 12:34 PM
thanks, but what ones do you usually buy?

boogiechile
06-11-2004, 01:52 PM
I use the JM series

JM12 (3/4") for ball joints

JM8 (1/2') for tie rod ends

JM7 (7/16') for upper a arm to frame mounts (you will not want to use this size here, I make my frame with a 7/16 mount hole. A JM8 with a sleeve to 10 mm would be what you would want)

LilDacktyle
06-11-2004, 02:09 PM
for the tie rods, i was just thinking about buying some. cause i know that you can buy some that are ment for +3 arm. do you think this would be better or jus to make my own?

boogiechile
06-11-2004, 08:05 PM
the ones you buy should be ok for you. They will not work for me on my new project because it has so much travel that they do not have enough range of motion. so i have to use the heims and they just barely make it even with a modified high misalignment pin.

bens250ex
06-11-2004, 09:39 PM
boggiechile would u be interested in making some +2 a arms for a 250ex some $$$$$$ defanantly would be involved for the labor????and parts

boogiechile
06-11-2004, 10:24 PM
bens250, i would really like to make stuff for people but I can't even find the time to finish my own project. maybe I should quit my job and build quads. It would be fun. but it aint gonna happen any time soon.

LilDacktyle
06-12-2004, 05:34 PM
i was wondering, can i use d.o.m. istead of chromoly?

LilDacktyle
06-12-2004, 08:45 PM
boogiechile, today i took my a arms off my banshee. i measured the bars or whatever you wanna call em that some out and conect to make the A thing. i measure them both. the front one came out to like 11 1/2, and the back came out to be 12 1/2. for instance, if i were to make the back one 1 inch longer, so that they would need to go father up to connect, would this make it like +1 forward? hope this makes sence, it was kinda hard to explain. thnaks

bens250ex
06-12-2004, 08:46 PM
boggiechile its ok u probable would make alot of money though working on quads..

LilDacktyle
06-13-2004, 10:37 PM
?

boogiechile
06-14-2004, 08:31 AM
Originally posted by LilDacktyle
boogiechile, today i took my a arms off my banshee. i measured the bars or whatever you wanna call em that some out and conect to make the A thing. i measure them both. the front one came out to like 11 1/2, and the back came out to be 12 1/2. for instance, if i were to make the back one 1 inch longer, so that they would need to go father up to connect, would this make it like +1 forward? hope this makes sence, it was kinda hard to explain. thnaks

It would move the joint forward but not 1 inch. One inch on the back arm at the angle it is at would move the joint far less than I inch forward. To make a arms you need to make a jig. The jig is set with the joints +1 forward or whatever you want and whatever width you want. the jig also must set the critical angle of the joint to acheive extra droop and not really any extra jounce without binding. The shock mount location determines the travel and motion ratio and has to be done right. Caster and camber have to be considered when the jig is made. Once the jig is set up you simply build the arms to the jig pattern. The jig holds everything in place while it is put together and welded. Again I will say that I think you are in over your head ttrying to make your own arms. There is much to be delt with that you seem to lack knowledge about. Heck, about half the name brand aftermarket a arms are not built right. I suggest getting a couple good suspension books and reading up before you attempt anything.

cinigen9
06-14-2004, 10:37 AM
boogie - I would like to learn more about this - can you recommend some books that you have found helpful.

thanks
Carson

EXJUMPER
06-14-2004, 12:05 PM
Originally posted by LilDacktyle
i was wondering, can i use d.o.m. istead of chromoly?

You could use it, but the main advantage to run chromoly is that you can use thinner material and still be strong.
Hey Boogie, do you use a tig or mig to weld them up? And if you use a mig, do you preheat / postheat? It looks like you do great work........keep it up.:devil:

boogiechile
06-14-2004, 09:19 PM
Originally posted by cinigen9
boogie - I would like to learn more about this - can you recommend some books that you have found helpful.

thanks
Carson

I really do not know of any particular books because i really have not read many but they are out there. You can do a search and find tons of them. "Race Car Dynamics" is a great book but it is kinda on the expensive side. My knowledge of the subject was just obtained over the years and geometry is my favorite field.

boogiechile
06-14-2004, 09:25 PM
Originally posted by EXJUMPER
Hey Boogie, do you use a tig or mig to weld them up? And if you use a mig, do you preheat / postheat? It looks like you do great work........keep it up.:devil:

Both. The components like arms and stuff are tig but some of the work on the frame is mig. I'm starting to like mig on the chromoly better than tig. we have stopped preheating and never postheated. we just let it cool slowly. I do not do the welding, I design and fab all the parts and tack them together with the mig. I have the welding instructor at the college I work at run the beads after I have it tacked together.

LilDacktyle
06-14-2004, 09:43 PM
boogiechile
i was looking at the ball joints or whatever you call them, and you said you use the JM series. i was thinking about it and dont you need the male end not the female end? cause you need something that goes through the hole on the spindle and holds the arm on. or do you just use a bolt or something?

EXJUMPER
06-15-2004, 09:52 AM
Originally posted by boogiechile
Both. The components like arms and stuff are tig but some of the work on the frame is mig. I'm starting to like mig on the chromoly better than tig. we have stopped preheating and never postheated. we just let it cool slowly. I do not do the welding, I design and fab all the parts and tack them together with the mig. I have the welding instructor at the college I work at run the beads after I have it tacked together.

Thanks for the reply! So in your eye there isn't anything wrong with mig welding chromoly without the preheat....? I've heard that mig welding chromoly without preheat will cause the chromoly to get brittle. I guess I'm just looking for some insite from somebody thats done it and uses it. Thanks again for the reply. By the way, why are you starting to like mig over tig? I have never tig welded....just curious:D
James

06-15-2004, 12:48 PM
I make my own A-arms too and I asure you that Tig welding is very hard to do. Mig is simple, just get the setting right and pull the trigger. Where as tig you have to have your tungsten sharp and know when to feed in more filler rod and how much. And you have to have a very steady hand. Tig is better too because it's a lot slower than mig and is more precise. Tig is a cross between oxyacetalene brazing and arc welding. If you're going to build your own arms I would only use chromoly because there are no seams and you really need to make a jig to get your arms exactly the same every time. Plus you will have a LOT of time in getting your measurements and all just right the first time you make a set.

boogiechile
06-15-2004, 03:31 PM
Originally posted by LilDacktyle
boogiechile
i was looking at the ball joints or whatever you call them, and you said you use the JM series. i was thinking about it and dont you need the male end not the female end? cause you need something that goes through the hole on the spindle and holds the arm on. or do you just use a bolt or something?

You have to use a machined king pin that is made for the 3/4 heim or spherical bearing and then has the taper to fit your spindle and bolt to it on the other end.

boogiechile
06-15-2004, 03:43 PM
Hez, the guy that does my tig welding is very good. His welds look fantastic and the penetration and strength is excelent. I have had no problems with cracking. Several race car chassis builders and the Natl Welders rep have told me that welding chromoly with the mig and 70-2 (i think) wire is ok without any heating. The race car guys like the mig better than the tig because it makes a larger bead the they feel is stronger and is easier to fill gaps if the joint is not made just perfect. (not to mention how much faster it is) I have no idea if this is all ok or not because I am not a welder but I have not had any problems so far with the tig or mig welds.

LilDacktyle
06-15-2004, 04:15 PM
where do you get this king pin? can you buy one at a store or do you have to have one specialy made by someone?

INFANTRY RACING
06-15-2004, 04:21 PM
on your super mojave wouldn't the amount the a-arms droop cause major washout (i believe this is the correct term) and but alot of stress on your ball joints and spindles.

dawnchris
06-15-2004, 04:29 PM
Originally posted by LilDacktyle
where do you get this king pin? can you buy one at a store or do you have to have one specialy made by someone?

GEEEEEZZZ.......just buy some arms and stop it already! No disrespect, but this is clearly going to be beyond you.

LilDacktyle
06-15-2004, 05:16 PM
shut up! i already started so i might as well finish it.

dawnchris
06-15-2004, 05:20 PM
More power to ya then. I might suggest trying standard balljoints to begin with, as they are inexpensive and easy to get.
P.S. I'm guessing you're between 16 and 19.:D

LilDacktyle
06-15-2004, 09:11 PM
how much more cheaper are the ball joints? haha, your close, im 15.

INFANTRY RACING
06-15-2004, 10:03 PM
if you want to mx sell that banshee and get a better quad

boogiechile
06-15-2004, 11:51 PM
Originally posted by INFANTRY RACING
on your super mojave wouldn't the amount the a-arms droop cause major washout (i believe this is the correct term) and but alot of stress on your ball joints and spindles.

Yes there will be more wash when the droop is more. wash is just the difference in width between when the quad is at ride height and at full droop. But the only way to get a lot of travel is too add it to droop. You cant get any up travel past the point the frame hits the ground so it is fixed. There is little extra stress on the ball joints unless it is designed where they reach bind. I spent a lot of time getting the angles just right so that it never reaches bind even with all that travel. 3/4 heims would be very difficult to break anyway without binding. The suspension I am running is really more like a desert setup with respect to travel but runs the lesser amount of caster like a mx. It should be smooth on the landings and handle whoops very good. I have been riding it the last couple days to break it in around on my property. I have no jumps to test it on but the cornering feels good and you can launch it hard and instead of doing a wheelie it lifts up and all that droop lets the frt wheels still stay on the ground.

I have designed a longer upper king pin than the one in the pics so I get very little camber gain at the lowest droop and with the single bottom rail even with all that travel there is hardly any toe change(bump steer).

If the wash causes a problem it will be on the jumps. I will post how it does once I get it on a track.

LilDacktyle
06-16-2004, 12:15 AM
INFANTRY RACING

i would sell it but i just got it and i got a great deal on it. it really use to be my dads so he sold it to me for like 3000. he wants to get another quad that is a 4 stroke and isnt quick and jumping like a banshee, so im goin to try to talk him into getting a 400ex and if i like those i might sell the banshee and buy one.

INFANTRY RACING
06-16-2004, 06:48 AM
yeah. i figured if it did it would be on jumps. probably not to bad on fast jumps but on slower ones it could suck. busting a bead off landing a jump would suck:blah: