My first project

[Denny]

Yep it was me. Didn't catch the paper thin wall thickness.

Shame on you! You should know better!

 

[ARU_CC]

This afternoon I was able to find a store where they sell iron, they only had 25x25 and 1.5mm, nothing more, so I bought 30x30x3mm, six meters, just as you told me.
I also have the two screws to use on the front wheels, these are m16x120mm. since my wheels have that diameter.

For the rear axle, should it be steel, or can it be iron?
In this place they only sell six meters of everything...

Another question I have, for the steering I have seen that there are times that the rod that turns the wheels sometimes goes in front and other times behind, is there a reason for this? Does it affect driving? Or does it still not affect?
For example, in the image I posted with the spring suspension, the rod goes backwards.

Many thanks

 

[Denny]

Study the “Ackerman Principal” for your answers there. I myself prefer front steer but that is just my preference.

 

[panchothedog]

Speedster, my mistake. I apologize. Since Denny has already berated EZ I will leave it at that. I did the same thing I was accusing you of, not thoroughly reading the post. Sorry.
ARU CC, your steel is perfect. It will be more than strong enough. The rear axle should be steel. Iron is much softer. Are you able to order parts from the USA, or is shipping prohibitivly expensive. The reason I ask, is because I would not recommend trying to manufacture it yourself. Live axle kits, many that include bearings, sprocket, brake disc, and even wheels and tires are plentiful here in the states, and can be had for less than the price of the parts individually. Plus everything fits because it is sold as a matched set.

 

[ARU_CC]

@Denny I've been reading Ackerman's principle, this has resolved some doubts for me, although the main question remains unresolved, since I haven't seen any reference to whether the steering point is in front or behind, it seems that it doesn't actually affects, the important thing is the angle that this direction has with respect to the central axis of the vehicle, for the correct turning of the wheels. It's my impression, correct me if I'm wrong.
Thanks for this point.

Reviewing videos I have seen that many amateur builders do not seem to have this consideration, you can see many 90º directions, the same as the image of the previous spring suspension.

I will take into account the correct angle to build it.

@panchothedog shipping is very expensive, for now I am going to try to get the parts locally, if that is impossible I will have to import them.

My next visit will be to a scrapyard to try to locate a motorcycle's rear sprocket, sprocket and chain.

Thanks.
Regards.

 

[Denny]

Correct Ackerman will help you turn better. Even with a Gokart it is important and will help reduce tire wear and improve handling. Rear steer may be your only option due to clearance issues. I just wanted you to learn why it’s important so you can make an informed decision on how best to accomplish it. Motorcycle chain and sprockets won’t work due to being the wrong size.

 

[ARU_CC]

Motorcycle chain and sprockets won’t work due to being the wrong size.

What if I multiply it? Do I use two motorcycle tooth plates to make a reducer?

 

[Denny]

That’s down the line a bit. Let’s see how much the kart weighs and what you end up using for an engine first.

 

[Rat]

What if I multiply it? Do I use two motorcycle tooth plates to make a reducer?

As long as the end ratio is complementary to the power you make and the weight it needs to move it doesn't matter if you have a direct input or a 20 gear reduction assembly.
Thats only slightly exaggerated for context, because the only limit is the amount of space it needs to fit into. HOWEVER, more than a single jackshaft reduction and things begin to become more complicated to calculate and even more so align everything.

I would know, I've got a Ducar 212 Hemi (factory race engine) stuck on what used to be a Tandem bicycle and the engine is double-jacked to reduce and power output on the right hand side as a 6 speed. There maybe 6 in the final gear range, but Ive only use the first 3 because it's just a scary ride when it begins to wind up the 30 series more than halfway in 3rd.

That’s down the line a bit. Let’s see how much the kart weighs and what you end up using for an engine first.

You Don't know what degree of power you need if there's no chassis weight to move, or bolt and engine to for figuring out how much room to play there is.

 

[panchothedog]

ARU CC. If you are keeping this a go kart build (you started out thinking it was a sort of a toy) so I don't think you are building a high horse power off road car.
So if you use a centrifugal clutch or a torque converter, the drive sprocket on either of those will not be compatible with any motorcycle chain or sprocket you will find. It would be terrible to have a completed kart and not be able to transfer power from the engine to the axle. Keep it all go kart, or buy the whole motorcycle including the running engine.

 

[Rat]

So if you use a centrifugal clutch or a torque converter, the drive sprocket on either of those will not be compatible with any motorcycle chain or sprocket you will find.

Not entirely accurate, but in terms of available junk... it's not likely one is going to find an old 1/2" pitch motorcycle easily.

THE REAL ISSUE is the fact that that motorcycles all have a transmission (full manual, auto-clutch manual, or full auto is irrelevant for point) and because of that transmission they need actually can't use a 6:1 final drive ratio, it's simply too low for street or trail use. So even if we're talking about pulling the gear off the hub... the following issues will be

1. Most common MC sprocket sizes are 40t, 46t, 48t, 58t

2. Almost all use a 4 bolt pattern far wider than any kart sprocket carrier can accommodate, and those that don't use 4 bolt are usually 6 and still not going to match up regardless.

3. Most common MODERN chain drives are 520 this has been covered you're not getting a 5/8" chain pitch on 1/2" pitch hardware
(I said not accurate, which is not the same as entirely wrong in this case)

@ARU_CC You are amongst a vast wealth of compiled knowledge, many of us "specialize" in certain categories, but overall there are a number of members whos advice or instruction should be taken as gospel.

I specialize in things that shouldn't be built, forcing things to work together that normally would never coexist on the same machine at all, carburetor tuning, and general trouble shooting.

My blind spots are cam cards, and EV's (I can not and will not respect an oversized RC toy with a pricetag twice as rediculous)

 

[Rat]

This afternoon I was able to find a store where they sell iron, they only had 25x25 and 1.5mm, nothing more, so I bought 30x30x3mm, six meters, just as you told me.
I also have the two screws to use on the front wheels, these are m16x120mm. since my wheels have that diameter.

Those look like unrated galvanized or zinc coated bolts to me... you won't ride on them very far before they bend if those are supposed to be spindles.
You need NO LESS than a Grade 8 hardened steel.
There's annealing that will happen when you weld them. You have no control over this, and it will soften the steel so you need something reasonably hardened to start so that integrity is not completely cooked out of them even if half the hardness is

 

[ARU_CC]

Once again I thank you for all your comments and knowledge.

I want to comment that I will not use the kart on competition tracks, nor will I be able to go out on the street with it, since this would have a financial penalty if they caught me.
I will only be able to drive it on private dirt roads.

Of course I am taking into account all the information you are giving me, right now I am designing my model in 3D software, to have a sketch of what I want to do, so they can validate if it is correct, and I can calculate the necessary material.

The screws are the ones I was able to get, I didn't know that they must have special characteristics, for now I will try to solder them and if they become deformed I will always be able to replace them.

This is the engine I will buy. 4 Stroke Gasoline Engine 208CC 7 HP 20 mm.
https://www.manomano.es/p/motor-gasolina-4-tiempos-208cc-7-cv-20-mm-15144792

I haven't fully understood why I can't use motorcycle sprockets on the kart, I know I will have to make adaptations, the idea is to be able to do everything myself, buying as little as possible.

Regards

 

[Rat]

The screws are the ones I was able to get, I didn't know that they must have special characteristics, for now I will try to solder them and if they become deformed I will always be able to replace them.

1. Those are bolts, Not screws
2. Soldering is for copper or tin toy restoration not steel steering components.
3. Based on your lack of experience, and hard head... It's gonna be your funeral if you don't take things more seriously.

I haven't fully understood why I can't use motorcycle sprockets on the kart,

1. You will play hell to match the chain to ANY modern motorcycle of any weight class
2. The gear ratio will be way off

I know I will have to make adaptations, the idea is to be able to do everything myself, buying as little as possible.

Good luck with that! This is not a hobby in which you can get away with that, some thing cannot be pulled from a scrap heap, and very little is cheap.

Since You take advice like a brick, I'm done. I do not have the patience, for this and there aren't very many active members that do

 

[ARU_CC]

@Rat I sincerely believe that you have misinterpreted my message and my attitude. I use a translator to write, since English is not my native language.
I do not consider myself to be a brickhead, in fact you have told me not to use the 49cc engine, to buy 3mm thick iron, not to use that bicycle crown, and I have followed your advice, as you can see in the previous message Where am I going to spend on that new engine.
If I were a brick head I would be starting the 49cc.
Of course, as the title of this message says, I am new and it is my first project, making mistakes will be normal, if it doesn't work, I will have to fix it and I will learn along the way.

 

[ezcome-ezgo]

I think the translation is causing a lack of continuity. DIY is the art of improvisation. Make what you have work.

 

[Denny]

ARU_CC you are doing great so far listening to us. I realize we have a language barrier and will work with you to overcome it. Together we will see it through.
Your engine choice looks great provided it has a 3/4” diameter output shaft. You will need to unplug the yellow wire from the engine to keep the low oil sensor from shutting off the engine in turns.