First attempt - 6DOF and learn to TIG weld at the same time.

From what I've heard the brazing is pretty strong, but a big part of that strength comes from its being used on lap joints. I have mostly butt joints to deal with. I'm going to take a closer look, though!

I have an Alphatig for my home shop as well! (Im also in NY go figure!). Your beads are getting better but your joints still look coldish. Get yourself a map gas torch or some other way to preheat the joint before you strike the arc. If your still mastering heat control preheating can help you ALOT. I'm sure you noticed as you go along and things get hotter its easier to move the puddle and add filler, preheating gets you there as soon as you strike the arc when learning! You dont want that sharp edged 'pile' bead, when its hot enough it blends right in to the surrounding material.

Keep it up!

Hi, @Xclone. Looks like you're about 2 hours from me! I'm close to Cooperstown. Thanks for the input. I agree that the welds in the photos are on the cold side. I was using a max amperage of about 130 at the time, and bumping that up helped. I do have a MAP torch and played a bit with preheating when I inadvertently was trying to use the foot pedal on the 4T setting and could never get past the starting amperage, so I couldn't get a puddle. It was driving me crazy. I'll keep at it...

Well then! I'm actually in Bouckville, so VERY close to you indeed! Perhaps a simulator meet up over beverages is in order!

@Xyclone, a meet up with beverages sounds like a good idea! I ran a few more practice beads this afternoon. Slightly higher max amps, and concentrated on moving faster, too. I think slow travel and too much filler rod might have been contributing to those heaped up welds. Feedback on these?

Def on the right track! Looks MUCH better penetration wise!

A little more progress. The main frame parts are now both assembled. Some welds I'm proud of, some I'll leave just as a record of the learning process, and a couple will be ground down and done over this weekend. Both parts seem pretty strong, though. And they're light. Trying to decide whether to make the seat frame next, or play with mounting the motors.

really great Sq.

doing same myself with a MIG welding kit, my pal is a welder so he's gave me some really good advice etc

Moving to an auto dimming weld mask with adjustable tint allowed me to actually see the burning weld pool and I can now be sure that both parts of adjoining metal is melting together

working with metal is a great thing to learn and we can create something that could cost many 10's of thousands , +grinding cleans up those welds as long as they are strong

cant beat welded mild steal boxtube for a rigid frame

Yes, the auto-dimming helmet is key. I have to get my face really close to the weld to watch the puddle.

yes I realise being close & watching like a hawk is key, really watch both pieces of metal and move at right speed etc,
I've been grinding too so its actually starting to look great,

made a mistake so had to use a grinder to cut apart again and boy the welded joint was soooo strong so there will be no issue

make sure you have a grinder with a grinding disk + cut disk but bet you have already

also I made some brackets that I've welded on & I'll you threaded rod for some attachments that might need to be adjusted in future rather than trying to use box tube/welded to and bridge everything

I use gas too and do on a bench just in back garden, I have to pick days with low wind otherwise the wind blows the gas around which effects the weld ! bet you gasless and indoors maybe too

After an unplanned hiatus to build a prop and print t-shirts for the high school musical, I'm back at it. Playing with mounting the motors, and I've come across a question. The simulators I'm emulating (like @SilentChill's) seem to have the motors mounted so that their shafts bisect the internal angles of the hexagonal frame. However, because I may have let form get ahead of function in my ignorance, I made a top frame that is not an equilateral triangle. So, my question is, will arranging the motors as shown, and attaching the rods to the "flats" on the top frame be completely unworkable? If so, I'll scrap the top frame and make a new one. So far, I haven't found a good source of info about the geometric constraints of building a Stewart platform, so if someone could point me to one of those, that would also be helpful. Anyway, here are some photos to illustrate what I'm trying to articulate:

What do you mean by geometric constraints? Do you mean optimal motor placement for maximizing different forces (roll vs heave vs surge etc)? I know there's a post somewhere on the forum where one of the users did a rough derivation of how placement affects performance, but I haven't been able to dig it up.

IIRC it's possible to make the top frame a non-equilateral triangle, but I think it makes the math behind moving the simulator more complicated than it would otherwise be.

Yes, that's exactly what I'm wondering. I think I can place mounts for the control rods in such a way that they approximate being at the vertices of a triangle, but it certainly won't be equilateral. If variances like that can be accommodated in SimTools, then I may go ahead and tack things up to see how it works. I just wanted to avoid welding everything up and then having to grind it all off if the shape makes it a complete non-starter. Thank you for the tip on the forum post. I'll do some digging.

Here is the post you are looking for... https://www.xsimulator.net/community/threads/basics-6-dof-stewart-platform.9396/#post-142706

Thank you!

Minor progress. I tacked up the motor mounts to see if the positioning will work, as I'm only about 50% confident, having no experience with this. Hoping to make levers tomorrow and make and mount control rod attachment points on the upper frame by the weekend so that I can see if the design as it stands will work or not.

The more I look at, and think about, that motor arrangement, the more convinced I am that it won't work because it won't allow for the translational axes of movement. Do the motors have to be arranged with their shafts bisecting the angles of the hexagon in order to get those movements? Thanks in advance for any advice.

EDIT: Yeah, I think I'm going to scrap the original top frame, and make a new one that is an equilateral triangle. Ground off the motor mounts, and now I wait for the next delivery from onlinemetals.com...

Motors in the right positions now. Waiting for some aluminum to make the upper frame. That and making/mounting the levers will be the after-work projects this week. Electronics are waiting for the brain box from Thanos, but he says he's close to shipping.

Should be ready to attach the top frame this weekend. Here's a a little update photo with the motors mounted and my, probably overly fussy, Hall effect sensor mounts (and you can see Thanos' brain box on the welding table in the middle of the frame). I have a question for the welders out there: I have to attach some brackets for the gas struts, but I don't know if it's safe to weld to the frame with the motors attached. Any advice?

@Squonk - the things to worry about when welding would be overheating but also electrical damage. It doesn’t look like you have any motor controllers connected yet so you should be good there. There has been at least one post I’ve seen where someone thought they had damaged controllers by welding with them connected. I’d have all electronics disconnected and moved away from anything you are welding. The motors themselves shouldn’t care as long as they aren’t part of the circuit. Overheating will have to be your call. Depends on what you are welding where. Looking good!