Replicating the mini thunderbolt

[Frotz]

I would like to replicate Eric Green's work of producing a mini-Thunderbolt siren. I asked him a few years ago for measurements, but he replied something to the effect of he didn't really write stuff down. Has anyone else tried to make a mini-Thunderbolt? I think I can come up with a blower fairly easily using a small AC pump from an air mattress. A rotator shouldn't be too hard either as long as I can find a good selection of gears. I have access to a lathe at a local hackerspace, so the chopper parts shouldn't be too tough. What really bugs me, however, are the dimensions. Would someone please be so kind as to measure the blower box, rotator box, the chopper housing, and horn of a fullsized Thunderbolt? I'd like to eventually come up with a set of CAD drawings for replicating Eric's work.

[Stormsetter4]

These are very rough measurements, and they don't include the horn. This is just the chopper and rotator unit:


22 inches long
14 inches wide
41 inches tall

[Frotz]

Is the 41" figure for just the chopper housing? How about its diameter?

[Stormsetter4]

Is the 41" figure for just the chopper housing? How about its diameter?

No, the 41" is for how tall the whole entire thing is. I will try to get a diameter tomorrow.

[CDV777-1]

I asked him a few years ago for measurements, but he replied something to the effect of he didn't really write stuff down.

You probably asked me for plans. That's my usual response when people ask me if I have "plans" for it. What I probably had at the time is stuff I used when I built it that nobody could build anything off of. As far as dimensions go I can think of at least 12 dimensions on the chopper rotator alone that you would need to make an semi-accurate model.
Then you get into the horn and horn bracket. When I measured the horn I ended up with a drawing with dozens of dimensions on it.
I have been contacted over the last (what is it now almost) 8 years by dozens of guys "who are making a mini thunderbolt" and want dimensions or plans etc.
I used to take the time to give out dimensions and info but after about the 10th person and no other mini thunderbolt ever materialized (or was even attempted) I figured why bother.
I have yet to see anybody else make one. There is one guy on youtube who made a really cool version (mostly out of wood) several years ago.
I think he was in Taiwan or somewhere. He did it on his own and didn't need any plans from me. That version of it was really impressive.

I don't see how you could possibly come up with "a set of cad drawings" for one without having access to an full size thunderbolt.

Ok. Reality check here.....

In your post you used

come up with a blower fairly easily

and

A rotator shouldn't be too hard either

and

so the chopper parts shouldn't be too tough

To be brutally frank you have no idea what you are getting into. To dismiss every step as easy, not to hard and not too tough is hilarious to someone who has
gone through the process of actually building one of these things. When I first started mine I never even thought about dimensions. I found a motor I thought I
could use for the chopper and started from there.


This is the first unstable rough version of the single tone chopper and stator I made for it. To say this "shouldn't be too tough" isn't based in reality at all.
If you don't have any real background it operating a lathe and holding close tolerances I don't see how you could do it.

I did eventually draw up a complete set of drawings to get a quote on a price to build the parts but since the chopper motor isn't available anymore
I never went any further with it. I would have to start all over with another type of chopper motor and I really don't have time to mess with it because
it's just to prohibitively expensive to have parts made and try to sell them.

[gman 1]

Eric, would you be willing to sell the mini thunderbolt?

[Frotz]

I guess what I'm trying to say is that I can conceptualize the process fairly easily. I'm not after a completely faithful scale model, but something approximately the same shape and proportions. Like your approach, things like exact size will be dependent on the size the chopper group ends up being.

[Bryan]

Eric, would you be willing to sell the mini thunderbolt?

I'm not sure why this was even asked.... I'd say be prepared to make a deal involving your soul, arms, legs and your first 3 kids!


But I'll let Eric give the official answer.

[gman 1]

Nevermind that question, I don't need it. Sorry

[Frotz]

This is the first unstable rough version of the single tone chopper and stator I made for it. To say this "shouldn't be too tough" isn't based in reality at all.
If you don't have any real background it operating a lathe and holding close tolerances I don't see how you could do it.

Can you tell me about the challenges of getting this portion working?