/diy/ - Do It Yourself

[Anonymous No.711865]

Hi /diy/

So I'm building a long john cargo bike. I'm basically using the rear part of an old mountainbike frame and welding the rest out of some steel tubes.

The problem is, I have never welded before, I suck at it and I also only have this cheap welder. It's a Harbor Freight 90A flux core welder I picked up at the hardware store.

Pic related is my first attempts at welding on a piece of scrap metal (it's the same tube I'm using for the bike).

Basically my question is this: How hard do those welds suck and is that purely my incompetence or does it have to do with the welder too? Let's say I welded the bike together like this, would it be likely to break under load? I don't need the welds to be pretty, it just has to hold and be able to support myself and a maximum of about 150lbs of cargo.

[Anonymous No.711867]

Practice more
Lower the amps
Slow your movement
Hold gun at an angle

[Anonymous No.711869]

OP here, here's a pic of the whole setup loosely on the ground, so you have a better idea about what I'm talking about.

Is there anything I need to pay special attention to when joining steel tubes like that? Do I need to leave a gap between them when welding? I have already chamfered the edges.

[Anonymous No.711873]

Does this one look acceptable? Best one I could get so far

[Anonymous No.711874]

Visit welding forums such as weldingweb and the Miller forum. All you seek is there, including info on how to practice. The Miller site has excellent training videos too.

[Anonymous No.711876]

>>711874
Well I know there's sources of information other than 4chan but I came here to ask you guys.

[Anonymous No.711882]

>>711876

Right. But... While the Miller website has well thought out walkthroughs and videos we don't. Go get you feet wet elsewhere, come back with some progress shots, then we'll critique your work.

[Anonymous No.711883]

>Harbor Freight 90A flux core welder

did they make that thing DC yet? i had to add a rectifier + capacitor to make it work decently

don't use the shitty wire they give you, get some lincoln wire at home depot (~$10)

[Anonymous No.711885]

>>711883
I dunno, I just plugged it in and it seems to work fine. Yeah I know the wire that comes with it sucks so I got some decent one.

>>711882
I've already been watching a ton of stuff on youtube and reading about welding, I guess I didn't mention that. I know how it should work theoretically, I'm just not very good at implementing that yet and still have a couple of questions.

Also why would I want to come here AFTERWARDS for critique? You'd probably crush my soul. I don't really wanna show you once I'm done because everyone's gonna say it's shit and then I will be sad.

I guess I'll practice some more until I feel more confident.

[Anonymous No.711895]

I've build several bike like this. I mig weld now; at the time was using oxy-acetylene and brass for joints.

You need to practice more. You're getting better but those welds look super-cold still and not continuous.

Rather than running flat beads on a piece of steel, try joining two pieces, then hammering them apart. If the welds don't break before the parent steel does, you're in good shape.

You won't be able to weld that thing on the ground like that. You'll need to brace up the pieces on boards to get them off the ground and ensure they are straight (rear triangle with wheel will be lowest point). Also, you'll need to final grind the joints down... ideally you want your gaps at 1/16", but 1/8" will be passable. Right now they don't look even close.

You are going to find that as you spot it together, the metal pulls around and knocks it off alignment a bit. So, once you get the joints ground and fitted, spot weld in 3 or 4 places around the joint. Do a final alignment check and if it's off, now is the time to do final bending of the frame. Spot 3-4 more places, re-check alignment.Then weld the sucker up. If you jump right to final welds, it can come out completely crooked and it's very hard to fix it at that point.

[Anonymous No.711915]

>>711895
Hey thanks for the tips.

I wasn't going to weld it like that, I will clamp the pieces down before welding and do one part after the other, making sure everything is straight. I have a digital protractor and water levels to check up on things before I weld them. I'll probably connect the scott frame with the rear wheel last because the rest should be relatively easy to get straight since the square tubing has flat sides. I had planned to do it exactly like you said with the spot welds, sounds like I'm on the right track.

As for the joints, that picture isn't the final thing, it was just an early test roughly put together to see if everything is the right size. I have since done some work on the joints to make sure everything fits, pic related.
I got one question though, do I HAVE to have a gap? The square tubing in the front fits together almost completely flush since I cut it with an angle saw. I did chamfer the edges though.

I'm pretty confident about the overall fit, everything came out quite nice. That's why I'm scared of fucking up the welding to the point where I have to cut something off and start over. I'll definitely practice more and try to join some pieces. How can I tell if a weld is too cold?

[Anonymous No.711920]

>>711865
>using a shitty $100 chinko buzzbox
>not spending a few hundred dollars more for something actually useful
Should have bought a stick, man.

[Anonymous No.711924]

>>711920
I heard that sticks suck for thin metal. The square tubing is like 3/4" thick but the tubing on the frame for the rear is less than 1/2" so I was afraid I'd burn through with a stick welder. Also heard they're even more tricky to learn for a beginner.

I'd have gotten a proper mig setup but holy shit the gas bottles are expensive. This is my first time welding, I didn't want to go all out and I don't do that much metal work. I pretty much bought it for this one project, if the frame doesn't fall apart it's good enough

[Anonymous No.711934]

>>711885

If it makes you feel better your welds look like goobery shit now.

[Anonymous No.711936]

>>711934
Tell me something I don't know

[Anonymous No.711938]

>>711924
That metal looks like it's about 1/4" or 3/64" which is doable with stick, all you need is small rods and to lower the setting

[Anonymous No.711939]

>>711865
I believe that for a long time, Atomic Zombie used only a cheap flux-core MIG (and an angle grinder, and some other cheap hand tools) on purpose.

The purpose being, to see what is possible with using only cheaper tools.

http://www.atomiczombie.com/
it's mostly recumbent bike stuff, but anyway.
You could argue that they are usually kinda heavy, but the welding looks just fine.

[Anonymous No.711946]

>>711915

The pictured joint looks good. That should work.

OK. To be clear, you should do a check for straight over the entire frame. Getting part 1 and part 2 lined up is important too, but getting all the bits to be straight at one time is another matter. Alignment issues tend to add up over time. So, point is, get parts straight, get whole frame straight, then weld it up final.

Even those square tubes have a gaps, just really small ones... no, you don't need a gap. I'd practice welding up some of the scrap square tube into joints, then hammer on them to see if they come apart.

If the weld is cold it's kind of like sticking something together with gobs of hot glue on the outside, vs. glue and clamp (and cold welds look same, like someone puddled up some hot glue.) A cold weld will snap cleanly between the filler rod and the parent material. A strong weld will appear to have melted the parent material in with the filler rod.

Ignore those telling you you need a 220V Lincoln tombstone stick welder. That is wild overkill for your application. Your 110V setup should be able to weld 1/16" material at full power, and that's enough. I have a Lincoln 110V mig/flux core welder; it will do up to 1/8" in one pass in flux core mode, and the welds look decent. Mig is much nicer; no spatter, you can do it with bare hands almost.

Ultimately if you stick it together with spot welds and align it, it will turn out fine. You will likely have issues with burn-through (holes) and cold welds. The former you can weld over, the latter you can grind out. The biggest issue to avoid is doing final welds and have it unusably crooked... cutting apart a crooked frame is a PIA but can be done... so avoid that.

[Anonymous No.711949]

>>711938

Tubing should be 1/16". If not that bikes going to be heavy as hell. I took apart an old Taiwan bike from 70's... really heavy, 45#. Thought it was the parts... frame was made up with 1/8" tube, and was insanely heavy.

[Anonymous No.711954]

>>711949
The square tubing is about 1/6". Yes it is heavy as fuck but after all it's going to be a cargo bike. It needs to be able to carry a lot of weight, goal is around 150 pounds. I can't have that shit bend when I put some beer crates on it and the bottom tube is so long that it needs be really sturdy so it doesn't flex. It's gonna be heavy either way but I'd rather have a few pounds more to move than risk it being too weak.

[Anonymous No.711963]

Braces, like triangles in the corners might be a good idea to just make it that extra bit stronger, as you say its gonna be heavy anyway might aswell make it strong as possible

[Anonymous No.711995]

>>711936
Practice makes perfect, you cannot expect to pickup a welder and make beautiful welds. it takes years to get it down right.

[Anonymous No.712740]

>>711873

Thats far from acceptable. Welds like those will fail.

See all the little holes? Thats porosity its gasses from the serounding air getting into the weld.

Are you using self shielded flux core wire?

If not:

-check gas pressure 1-2 bar
-check flowmeter 12-14 l/min
-check for leaks in gas hose/welding machine/torch
-check gas distributor in torch

If thats all good and gas is flowing out of the torch. then your stickout is too long and gas isnt shielding the weld. Your stickout cant be more then 1,5mm.

Also it looks like yout settings arent correct, But it could be de gas problem thats causing that. fix that first.

[Anonymous No.712750]

>>712740
what this guy means to say is, raise the amps by a little bit and try again
you should have a pool of metal about half as high as it is flat

adjust the wire speed and amps until it makes a consistent crackling sound

[Anonymous No.712823]

Grind off your mill scale on all of your joints. You will get better penetration and less likely to get slagtacular beads that don't want to chip for shit.

Grind between passes..

Move around switching sides after each weld so you don't pull anything out of square.

when you make a tie in, overlap and then grind off excess, don't stop at the very beginning of the weld.

Your fit up looks fabulous.

[Anonymous No.712843]

OP here

>>712823
I'm using a cheap-ass flux core welder that doesn't use gas so I can't really adjust anything there. I figured the holes aren't good and are due to not enough shielding gas but I can't really do anything about that.

>>712750
The welder also only has two amp settings, 45A and 90A. 45 is a fucking joke so I'm pretty much stuck with 90. The only thing I can adjust is the wire feed speed, I've played around with that already but it doesn't seem to help much, if I set it too high I get lots of splatter so I leave it on about 50%. Problem is that the wire doesn't seem to come out evenly, it's kind of inconsistent and stuttery which causes the wire to push the welder away, I think that's why the welds are so uneven. One other problem is that even though I have an auto-darkening helmet I can't really tell what the fuck is going on as soon as I start welding but I guess that's a matter of practice.

THAT BEING SAID I just did what anon suggested and tried to join some pieces. I joined my test piece and the rest of the down tube of the old frame. As expected the weld is the fugliest piece of shit ever but I gotta say it does seem sturdy as hell. I, a 200lbs guy can jump up and down on it and doesn't crack or move an inch. I'm pretty sure if I tried hammering it off, the downtube would break/bend before the weld.

So I guess my question is, how important is it that my welds LOOK good? In the end it's just metal molten together right? I'm not sure I'll ever get pretty welds with this equipment even with practice so can't I just weld it as well as possible doing multiple passes, then grind it down and do another pass where it's necessary?

[Anonymous No.712852]

>>712843
generally speaking, a good looking weld is a sturdy weld
but you can probably get by with that

[Anonymous No.712855]

>>712843
If the wire is pushing the handle away you don't have enough heat / too high wire feed speed.
that said, your welds will be full of pores which will fuck with the integrity of your welds. Using piece of shit wire with no shielding gas won't produce any stellar welds and you can't really be sure if they will hold, even with multiple passes.

I would really try to borrow/rent a small stickwelder for this.

[Anonymous No.713032]

Hey, that will work . If you can beat and pound on the joint and it stays together that's all that matters.

The stuttering that you describe is, I think, you losing conduction due to flux and other contaminants. With the welder you are using shiny metal will be the best way to go, and that includes when you redo welds. Some mentioned converting the welder to DC. That might help, but probably beyond scope of your project.

As for your question: a shitty looking weld that holds is fine. You can grind the extra material and fix porosities if you want. The job will probably look better. Porosity can introduce rust, ugly welds are just ugly, but frankly not sure your setup can produce good looking welds. Once you do final weld, grind out the welds into filets. This will expose porosities. Weld in these holes, regrind. Its a bit of a pia and that's where a more expensive welder pays for itself... Less rework.

[Anonymous No.713088]

You can try preheating it, see if that helps at all. In all my years of welding, ive never used a self-shielded FCAW, only gas.

Make sure there isnt any drafts where you are welding. If I think of anything else, ill let you know. Too busy studying for my journyman/redseal. And like everyone else has been saying, practice.

[Anonymous No.713096]

>>711865
Your welds do not look very good.
The flux core process can produce strong and excellent looking welds.

Some questions:

What welding wire are you using ?

Does your welding wire size match your welding tip ?

What is the recommended max steel thickness for your welder at 90 amps ?


Make sure the ground clamp is on clean metal for the lowest contact resistance.
Also make sure any user accessible cable connections are tight.

It looks like you are having trouble maintaining a consistent steady arc.
Are you having trouble with the arc breaking spontaneously (say from wire feed problems)
or due to skill at maintaining holding angle/ distance ?

You might try practicing on different thicknesses of material. There should be some combination
of metal thickness and wire speed that will give a near perfect bead at the 90 amp setting.

You could also try practicing with a guide, such as the piece you show, for resting and moving
your welding hand along.

Crummy welds can be surprisingly strong, but your welds seem a bit off for a real project.

If you eventually can't get good beads, it's possible the (new ?) welder has a problem.

[Anonymous No.713103]

>>711865
Are you getting close enough to the weld?
Sometimes beginners try to "wing it" at arms length while welding.
Your face mask should be about 6 or 7 inches from the arc so you can
really see what you are doing. Make sure your hair is OK with potential
splatters. Once you get a good bead going a sound described as
"frying bacon" on a good welding pass is a key indicator of correct
technique. You really need to be attentive to your weld puddle
and be making minute adjustments, this is where practice comes in.

[Anonymous No.713145]

>>711865
>>711873
How do you weld that badly?

[Anonymous No.713147]

>>713145
I'd like to see your first weld
> implying you even know how to strike an arc

[Anonymous No.713181]

Here's a pic I found of someone using same HF 90A AC welder with the HF included wire. This is what weld should look like. Nice puddling, good pemetration. The spatter is unavoidable with a flux core setup.

[Anonymous No.713228]

OP here

First of all thanks to all you guys, this board is actually really helpful, I appreciate the advice

>>713181
Well shit, that does look a lot better. I'm honestly not sure what I'm doing wrong, can I fuck up that much simply because I'm moving the handle in the wrong way?

>>713145
Fuck if I know man, I just press the button and try to do little e's like I was told and then it comes out looking like ass.

>>713103
Yeah I hover over the weld with my head pretty close, it's still hard to see what's going on but that's most likely due to inexperience

>>713096
I use wire I bought at the hardware store, not sure what it was called but the guy said it's better than the stuff that came with the welder. The wire size matches, I made sure of that. The unsteady arc is definitely the biggest problem, the welding is not consistent but I'm not sure what's causing that. Clamp should have a good connection and I always wire brush the areas where I weld before I start.


I think the stuttering might be due to a combination of factors, loss of conduction being one of them and maybe the wire speed too, I'll play around with that some more. When I set the wire feed speed lower though, I need to move more slowly to keep the puddle going and then I noticed that it tends to burn through the metal a lot. I think the welds would probably look better if the arc wasn't so inconsistent but I have no idea how to achieve something neat like >>713181 posted.

I'll go watch some more welding videos...

[Anonymous No.713254]

>>712843
First post on this thread.
Think about this: the better it looks, the healthier the weld is. (Ok some exceptions may apply).

Keep practicing. Don't weld the fram yet. Just keep honing your skills until you see your welds and think "This weld looks so sexy I wanna make sweet love to it".
You know why?
You really know why?

You don't wanna fall off a bike that just broke in a welding point.

Ask Ayrton Senna. Fucking died cause a bad weld.

[Anonymous No.713256]

>>713254
I sorta agree with you but then again I don't want to let this project wait for years until I'm an expert welder. Besides I doubt it's possible with this equipment anyway. I'll definitely practice some more but I'm not gonna become a pro at this to build one bike, it just has to be good enough.
I agree that I can't have this thing fail on me though so I'll make sure to do some stress testing before I take it out into traffic.

[Anonymous No.713268]

>>713228
>I think the stuttering might be due to a combination of factors, loss of conduction
>being one of them and maybe the wire speed too

If for any reason you lose the arc, use a stiff wire brush to remove scaling before starting again.
The flux residue on the workpiece can cause all kinds of stuttering problems.

>When I set the wire feed speed lower though, I need to move more slowly to keep the puddle going
>and then I noticed that it tends to burn through the metal a lot

This is why it might be helpful to practice on thicker stock to develop coordination.
Then it will be easier to deal with the burn through hazard on thinner stuff.

>I think the welds would probably look better if the arc wasn't so inconsistent

You need to know what a proper bead produced with the correct wire stick out feels like.
This can be difficult for free hand beginners. Set up a guide to run your welding gun along
then play with the arc distance, wire speed, welding speed, and gun angle on a piece of
1/4 inch steel, until you get a bead that looks like
>>713181.

Once you get practiced you should be able to run at least 8 inches free hand in a single uninterrupted pass.

[Anonymous No.713269]

>>713268
When you say use a guide, does that mean I just drag the handle along in a line? I thought I was supposed to sorta go up and down and make it overlap?

[Anonymous No.713271]

>>713269
A guide means basically a "rail" parallel to the intended weld bead
that your hand or the near tip portion of the welding gun can travel
along for more stability. You can be creative on clamping your work
so that you have such a guide near the weld area.

[Anonymous No.713279]

>>713271
Yeah I know. But when I use a guide that means I would move the handle in a straight line. I was told in many videos that you're supposed to to a zig-zag motion or something like writing cursive E's with the welder. That's what I've been trying so far. If I just need to move it in a straight line that would make things a lot easier actually.

[Anonymous No.713288]

>>713279
You get that zig zag or e motion more from tilting of the gun. Your hand and the gun need to
basically move in a straight line to track a typical weld joint. A guide can also aid in maintaining
the stick out distance which is critical +- 3 mm for the best weld. Sometimes people just drag
there wrist on a table edge or such for more stability.

[Anonymous No.713362]

>>711865
Here is something on all this that seems to relate to splatter and appearance issues.

A quote from the Harbor Freight review section:

>The single biggest problem with this machine is that it outputs AC current.
>This results in ugly, spattery, porous welds with very low penetration.
>There are NO wirefeed processes that should be done on AC. MIG is done DC+, and flux-core is done DC-.
>I added a bridge rectifier and a power factor correction capacitor to mine, and it turns it into a
>totally different machine, producing clean, smooth beads with good penetration. The minimal cost it
>would take for harbor freight to add these features into the machine would be well worth it, and make
>this welder really worth the money.

Here is one website that describes the modification. Their are others.

>http://www.blinkenbyte.org/welder_conversion/welder_conversion.html

[Anonymous No.713439]

>>713362
That's an interesting find but I wouldn't feel comfortable doing those modifications myself on something that uses that amount of electricity and is potentially dangerous as it is. I'm not an electronics guy so I'd likely electrocute myself or blow the thing up.
Good to know it might entirely be my fault that the welds look fugly though.

I'll do a few more practice runs this week and I think then I'll just go for it and report back here.

[Anonymous No.713471]

>>713362
It's interesting how people can be massively competent in one area, and have massive holes in another. That guy can build power supplies, but he's using a massive transformer to power a fan, where a phone charger would be smaller, cheaper, easier, and more efficient.

[Anonymous No.713481]

>>713439
>that uses that amount of electricity and is potentially dangerous as it is

It's probably not that dangerous, were talking < 30V output.
The tricky part is finding all the components cheap enough for a low cost project.
My brief survey showed several people have successfully done it.

Anyhow, if you look at the photos, I would say all beads are acceptable, as far as general integrity,
except perhaps the third from the right on the top photo. Your welds are not up to this standard yet,
but you do seem to be having less splatter.

[Anonymous No.713482]

>>713471
Thats not the problem. Avid DIY'ers often tinker like that.
The problem is he needs a schematic for the overall mod on the page !

[Anonymous No.713725]

This guy did an entire series on this welder including the mod to DC... Excruciatingly detailed. Video one of about a dozen below.

Easy Harbor Freight 90 Amp Welder Mods 01: http://youtu.be/_YHWb93-6PU

[Anonymous No.713889]

>>713181
damn that's pretty nice. i can get similar with the same welder + rectifier + lincoln wire

hobart wire seems to spatter a lot, lincoln doesnt

[Anonymous No.713922]

>>713725
OP here, thanks, this is really helpful. I'll try doing some of those tweaks, especially welding without the cover thing at the tip so I can get closer to the weld.

I gotta say even though this welder sucks I kinda like welding. If this project works out in the end I might get a good welder in the future and work with metal some more.

[Anonymous No.713957]

>>713922
Consider doing what I did. Take in some minor jobs at 20 to 40 a pop until its paid off. Did this with my little 110v Lincoln mig until it and bottle was paid for.

[Anonymous No.714260]

OP here again

Alright guys, I did some more testing and I'm pretty sure now that my main problem here is the welder. I just can't fucking get it to produce a constant arc no matter what I do. I took off the tip from the handle like suggested in the video and made sure I keep a constant, small distance to my workpiece and I wire-brushed the hell out of both the spot I put the ground clamp on as well as the spot where I'm welding. But I keep getting this stuttering where the arc breaks for a fraction of a second all the time which causes the wire to push away the handle and which makes it impossible to actually keep a puddle going. Hence I get these horrible, blobby, inconsistent welds. I'm guessing this behavior isn't normal? The wire should be coming out smoothly and evenly, not stutter, right?

I've tried a number of things but nothing seems to work, I even tried different power outlets, wire feed speeds, etc, I also tried pushing the weld, pulling it, going sideways, same shit every time.

The weird thing is it used to work at least a few times in the beginning where I could at least get a somewhat uninterrupted, albeit uneven bead like in >>711873

But now it's stuttering so much that it's impossible to get anything but these fucking blobs.

When I just press the button without welding, the wire comes out smoothly so it's not the feed mechanism.

What the fuck do I do guys? Should I just sell this piece of shit and get a stick welder? I'm out of ideas here.

[Anonymous No.714275]

>>711915
If you weld to the bottom bracket like the pic, it will distort, those are fine threads.

[Anonymous No.714277]

>>714275
Well, many people have done that before though. I might put in the BB cups to keep it from warping too much.

[Anonymous No.714302]

OP here again, sorry for all the posts

Ok so it turns out I'm a fucking retard after all. The problem really was conductivity but I didn't try fixing it hard enough. I used the wirebrush (the one you hold in your hand) to prepare the contact areas but that wasn't enough. I'm guessing there's a lot of residue on this metal from storage so the contact still wasn't good. I finally tried using the wirebrush disc with my powerdrill to REALLY brush that stuff until it's shiny and what do you know, suddenly I get a steady arc. I was actually able to produce some somewhat decenti-ish, even beads this time. I found it also helps to move from side to side a little so they're more flat and not as tall.

I think I might actually try welding the goddamn frame now. I'm running out of scrap metal to practice on anyway.

By the way the porosity you see only happes at the end of the weld, I tried grinding one down to check and they're solid inside.

[Anonymous No.714375]

>>714302

Atta boy. If it makes you feel better, I failed my metallurgy test today at trade school.

[Anonymous No.714383]

>>714302
Substitue wire brush for angle grinder mounted wire wheel.

[Anonymous No.714432]

>>714383
If youre going to use one of these be very, very fucking careful. Honestly, just dont use it.

Anyways, practice your welds lengthwise, not along the short length of the scrap. Your welds are fucking bad man, Im scared for you. Youd be better off finding a friend or hook up at a shop or college and use a decent welder, this 45/90A shit is retarded.

[Anonymous No.714443]

>>714383

Those wire wheels are fucking god-send. This >>714432 anon has a point, though, you need to be careful with them.

>Don't brush a corner or an edge
>Don't put the grinder in a position where the unguarded side of the wheel is spinning towards you.

They like to snag and throw little wires like the needler from Halo. Just wear safety glasses, don't hit corners, and don't use it on small pieces.

[Anonymous No.714446]

>>714432

Come on man, the last three he posted look good enough. It's not like he's building a bridge for tanks, it's for a freaking bike.

Pretty welds are overrated anyway, people are fucking obsessed with them. As long as it's consistent, solid and you get good penetration it'll work for 90% of what the average hobby guy builds. I've done some ugly-ass welds in my time and so far none of them have ever broken even on stuff that takes a lot of abuse.

[Anonymous No.714447]

>>714443
quality control is out the window on these, good luck getting one that is well balanced.
took me a while to find one i could use comfortably for any amount of time.
unless you like pins&needles sensation in your hands for a few hours.

[Anonymous No.714448]

>>711865

So, I read all these posts. Why haven't you considered brazing OP? A lot of professional and high-end frames are actually brazed rather than welded (for various reasons, not because they can't afford good welding equipment, but because it's better in many ways)

Brazing is generally easier and lower heat than welding, less damage to the metal and re-doable/fixable. My advice is to look into that.

[Anonymous No.714452]

>>714447
It's true, they also tend to shoot those wires all over the fucking place and if you ever step on one without shoes, have fun pulling it out of your foot, happened to me more than once.

I think it's because angle grinders spin so fast, these shitty brushes just can't take that much energy. That's why I prefer using something similar with a cordless power drill instead where you can vary the speed, it's really not necessary to spin them that fast for what you need them to do. Angle grinders are scary brute-force kind of tools.

[Anonymous No.714458]

Actual TIG stainless steel pipe welder here OP. If you have any questions shoot em this way. I'll be monitoring the thread but so far looks like all these boys got you covered.

[Anonymous No.715354]

OP here

tacked the frame together today, I did a shitton of measuring and it paid off, everything came out nice and straight, I'm very satisfied. The tack-welds are pretty strong too.

Tomorrow I'll finally weld the fucker up for good. Be afraid.

[Anonymous No.715361]

>>715354
Godspeed

[Anonymous No.715432]

Hello OP. Bicycle wrencher here. Im wondering what kind of parts and brakes your planning to throw on there?

[Anonymous No.715506]

>>715432
I got a new 26" MTB rear wheel which hopefully will be tough enough, a 20" front wheel from another cargo bike and for the drivetrain I don't need anything fancy, I still have some old Shimano Alivio 3x8-speed parts laying around that I'm gonna use. For the brakes I'm gonna use Avid BB5 mechanical disc brakes (hydraulics are too much maintenance for me on this kind of bike) with 180 discs in the front and back. That's pretty much it, mostly used stuff, nothing too fancy except for the brakes maybe.
The frame and fork actually don't have disc-brake mounts so I'm going to have to make and weld those on too - wish me luck.

[Anonymous No.715605]

>>715506
Spacers from V brake pads is your friend when mounting calipers to questionably straight mounts.(Your wielding might be good. But they need to be spot on to ride without them). I would probably still go with hydraulics. Shimanos are bulletproof and alot cheaper now than they used to be. Im afraid that much weight is gonna have you readjusting the stationary pad every week. Better to just get something that does it automatically. And bleeding is not that hard once you get used to it. Also rotor size is your friend on a build like this. Better to spend the extra cash and get 203mm's.

Good luck with this. My apprentice rides a 70s model he completely rebuilt himself. He keeps telling me how practical it is and how i should get one myself. But i find the trunk of my minivan plenty practical :)

[Anonymous No.715608]

>>715506
also. Dont worry too much about the rear wheel. Most broken spokes are from riding torsion. Not weight load. If its a cheap wheel just ride careful. Which wheel is it? (Rim make/model?)

[Anonymous No.715614]

>>715608
>>715605

It's a 32 spoke Mavic rim (XM 319) with DT swiss spokes and a deore hub. As for the brakes, according to Avid they actually have automatic adjustment so that shouldn't be a problem. From what I hear they're really good and perform almost as well as hydraulics. My plan for the mounts was to actually put in the wheel, put the brakes on with the mount attached and pull the brake so that it's held in place on the disc, then weld the mount onto the frame while it's positioned by the brake. In theory it should be in the right position afterwards but who knows.

That's a great tip with the spacers though, I might try that if I can't get the alignment right.

[Anonymous No.715623]

>>715614
Wheel will be fine. Eventually the axle might snap or bend on that wheel. But they are incredibly standard and are pretty much identical to whats sitting in most random wheels in scrapbins. So a replacement is quick to find.

As for the bracket on the back. there are some adaptors out there. A2Z makes one that are relatively small. Other manufacturers make some larger ones that mount to the V brake mount aswell. Might save you a headache to look into that. ive never used one. so cant say how well they work. But my general experience with a2z products are solid.

I also heard the BB5s or BB7s are the only way to go with mechanical. Personally i never really understood the craze. My experience with mechanical discs has always been bad. They never perform good. they just perform acceptable

[Anonymous No.715858]

>>715354
Nice work, looks great. And glad to hear you've gotten welding down now with your machine.