Spider Project Part 3

Okay after a slight break from working on this project to attend to other things I've finally gotten back to it.

I realized that I had a design flaw in the cam mechanism that had to be remedied or this thing would never work like I wanted it to.

The Problem

The cams where wiping down the follower arms which was causing some of them to get stuck.
They also were getting caught on the edge of the caps I was using as followers.
This was causing it to take too much effort to turn the crank and was causing a very uneven motion.

The Solution

I put 90 degree angles on the ends of the follower arms.
This did two things: 1. Kept the cams from contacting the arms and 2. got rid of the lip that the cams
were getting stuck on.

See How Nice It Works

It is also much easier to turn the cam by hand now.

The Whole Enchilada

In this video, the back end (ahem) of the spider is facing the camera.
The movement is a bit squirrelly with the drill but looks better when done by hand.
If you really want to track the legs movement play the video on slow.
I'm personally leaning towards the idea that the jointed-muscled legs are more trouble than they are worth.
I do like the motion, how the legs reach out as they come down.

Another thing that I realize is that the 'return springs' are not optional. Even with this newer more efficient drive train I feel it still takes too much muscle to turn the crank without them and they keep the followers from falling off the cam.

The Plan
Start converting this prototype into a 'real mechanism'.
I will replace the wood structure with a light weight minimalist metal frame.
I'm going to have to farm out the fabrication of the cams. I think that using UHMW plastic for them is a great idea. I need them to be perfect and a CNC mill can whip them out in like 5 sec.
I haven't decided if I can just use the followers as is or if I need to redo them also.
It seems like the PVC wiping on UHMW plastic should last forever.
The grey PVC pre-bends riding on a threaded rod I'm not so sure about.
Using the 1/2" PVC for the legs doesn't seem like a problem for me.

Okay, anybody have any ideas?

Spider Project Part 2

Spiders, Spiders everywhere....in my dreams and underwear.....

Okay, lots of fumbling around in the dark about how to make a cool lightweight spider.
I've searched the interwebs to no avail...it appears that this particular project has not been attempted in this particular way....bummer...

Pictures of the cam and leg mechanism.

Close up of the cams

 The springs are there to help take the weight of the legs off of the cam. They are set so that when the legs are at their lowest they are just barely negatively buoyant.

In the above shots you can see my plywood cams, my cam followers, and my roller bearings! Or, 1/2" grey PVC pre-bends and end caps.
One of the problems in this prototype is that the plywood kinda catches on the edges of the end caps.
The final design will have to have a smooth transition.
That and because the cams are mounted on threaded rod they keep creeping forward when I'm testing.

Yep, plywood, pvc, zipties, threaded rod, nuts and washers. How professional!

Here's a little close up shot of the cams actuating the legs.

Remember, this is just a prototype version 1.0. If you can see anything that I could do to improve the action please let me know.

And finally the whole thing moving.

Doesn't look to bad right? I think that there is a pretty good amount of movement in the legs. One thing that keeps happening is that the cams all try to 'self align' which makes it really, really hard to turn the crank. I set them up with the two outside cams at 90 deg from each other and the two inside cams 45 deg of off them. In the above video the legs are rigid. I'm thinking that the spider would look a lot better is the legs maybe moved about. I decided to try to hinge the top 90 deg fitting and see if I could get some added movement.

Enter The Hasp

This is super kludgy. This hasp is not a long term solution.

Some bungee cord muscle

And when the leg is in its lowest position the bungee pulls the lower half of the leg up a bit. Not a whole lot of movement.

The right angle is how the leg would look if it was rigid. I don't  know if this much movement is worth the hassle. Leg Moving.

Wha da y'all think?

Questions Can anyone see any improvement that can be made? Is the leg movement worth it? How in the heck am I going to go from this and into the real deal? This will be powered with a windshield wiper motor. I still have to figure out how to connect it to what ever shaft the cams will be attached to. What should I make the final cams out of?  

Halloween in April

I've got exciting news!
A neighbor of mine wants me to build him a Halloween animatronic!!!!!
Crazy right?

Let me introduce my friend the Wolf Spider.

 When you think of freaky-scary spiders is this not the picture that comes to mind?
These things are great. Big, hairy, they don't build webs. They use those long legs to run really fast and jump on their prey to grab em. Now imagine one of these things with a two foot long body running along the ground and leaping up to grab you! Yep, nightmare machines.

The plan is to make a spider that leaps up from the ground and moves forward toward the trick or treaters while making a horrible sound and clacking its 'fangs' together.

The prop has to fit the space which is a bit tight (see below).

Scaled Haunt Map

That's about as big as I can make the spider and have it fit the parameters. The idea is to have it leap up to just above the level of the hand rail on the stairs while not intruding into the six inch safety buffer.

How am I going to do this?
With what's called a 4-bar lifter.
That would be the tower and the two diagonal lines in the below diagram.

 When in the resting position the spider will actually be 6" off the ground so it will look like it is standing on its legs.

Up Position

 Boo! c'mon that's gonna be a pants wetter right?

Spider

 Yes, I can not sketch artfully.....and the 1' should say 6".

Help!
Just about everything in this project I have built before for myself. There are two things that I don't instantly know how to do best.
1. My neighbor would like me to make the legs wiggle when its up in the air. We need to keep the spider itself as light as possible. I thinking of some kind of spring loaded leg assembly as shown horribly below.
2. How to best make the moving jaws effect which is also sketched out horribly below.

 I'd appreciate any helpful suggestions on these last two points.
This is going to be an interesting build as the spider needs to be as light as possible but also stiff enough that it doesn't flop around on the end of the nearly 4' long arm.

Update
Some clever folks suggested some ideas on how to give the legs some movement.
I've distilled the ideas into the following two sketches.

Hope that makes sense to someone.
I'm going to try to build a prototype ASAP.


 

Pipe Boxes

I built these a while ago but I thought I should post about them so that the pipe organ nuts will get off my case about how I was miss-treating the metal pipes ;)

Wow! Do I have a ton of pipes......

Building Boxes
Pipe organ pipes are kept in 'pipe organ pipe' (theres gotta be a better way to say that) boxes. I think I'll call them POP boxes. A nice PON (that's pipe organ nut) sent me plans on how to build them which I completely ignored and did my own thing....

Lumber

The boxes consist of a half sheet of 1/2" plywood and some 1by6"s glued and screwed together to make an open top box.

Finished Box

A finished box! The first one of many....

Then it was sort the pipes fill a box build another box fill it and on and on. I honestly didn't realize how many pipes I had until I organized them....wow more than I can use for sure...

Now, exciting pictures of POP's in boxes! Woo!

Probably should of used 1by8"s so I could of fit bigger pipes in the boxes.
Can you read the sides of the boxes? I've got two sets of Melodia pipes, Dulc, Salc, Fl Har, ST Dia.
What I thought was interesting is that the wood pipes from the Hinners Tracker Organ all had some tiny metal pipes as part of their rank.

Oops

Of course after everything was stacked and layered I found a metal pipe for a set that was completely buried.

After I stacked and boxed all the 'little' sized pipes I was able to organize the 'big' pipes.

These pipes do not have any identifying marks that I could see. These are also the pipes that suffered the most from the leaking roof.

Leaning Tower of POPs

Most of these pipes are so darn huge that I have no idea how I could produce enough wind to make them 'speak'. I'd bet those big ones on the bottom would make house shaking bass.

Here's a cool thing about these unknown POPs.

They've all got these, uh, built-in valves.
With all the POPs sorted I was able to organize the façade pieces a bit.
I wish I was able to save more...did I mention how the monkeys that took this thing apart used crow bars instead of unscrewing ANYTHING? Freaking hate those guys...

Façade Pieces

These façade pieces pictures were supposed to be a single panorama shot but somehow I screwed that up....the camera is smarter than I am......

Next Up
A paying Halloween gig?!?!

KnifeCatching 715 Grand St.

Read This:The following review is just my opinion and only my opinion I am not a professional house appraiser or inspector and I am not a structural engineer. The opinions expressed in this review are based on my own inspection of the property, the publicly available facts from aggregator sites such as Redfin and Zillow and the online permit database for the city of Alameda. I am not responsible for incorrect or missing data that appears in these sources. In fact, its probably best that you just ignore everything you read here as the lunatic ravings of an unbalanced mind.

KnifeCatching 715 Grand St.
Up for review today is 715 Grand St. which has the official specs of being a 4-2.5 of 3,081 sq ft on a 7,500sq ft lot built in 1920 listed for the low low price of $1.22M last sold in '06 for 1.38M. The redfin page can be viewed here.

This house was last on the market about a year ago for the same price and it did not sell. What do you want to bet it sells this time? They might even break even on the 'peak price' they paid.

What The Permit Record Tells Me
New roof in '06!
Some remodeling done with permits! Hurray!
A perimeter drain and sump pump was installed in the basement.
The current owners have not offically made any improvements to the house.


A Small Tour
Sorry, the batteries in my camera died on me half way through but the RedFin page has tons of pics.
Man, I haven't done this in a while, my 'photograph the important features' muscle is a little weak...
So in no particular sensible order....

The Master Bedroom

This is a really good sized room with like a sitting/reading room.

Master Closet

 Its a little cramped in there...

Master Bath

Nice natural light from the sky light.
This is a pretty big room..but there's no tub?

Kids Bath

Love that tile on the floor....not.
But at least you don't have to share a bath with your teenagers.

Kids Bedroom 1

I thought this was a reasonable size with a decent sized closet.

Kids Bedroom 2

 This is also a good sized room.
Around the corner you have this little room.

Sorta two rooms in one?

Little half bath on the main floor.

Sorry, but, fugly tile.

Garage

 Long and skinny, good luck getting a modern car in there

The driveway also seems VERY skinny to me...You are definitely not getting your Cadillac Land Destroyer in there. Does this house only have off street parking?

Okay, here is one problem that I see...They converted part of the garage into a home office.
I don't see this anywhere on the permit record...In Alameda this is a big no no.

Super Cool Outdoor Party Spot

 This is my fav part of the house, the backyard and this party spot. This would be such a great place to have a 4th of July party. Sit on your front lawn with all your friends to watch the parade go by and then retire to the backyard to BBQ.

This is a cool little feature too. Not sure what it was originally. Maybe a summer kitchen? A canning kitchen? Stock those cabinets with party supplies, put in a fridge and natural gas grill and you'd be ready to paaar-tay!

Hmmmmm....

I'd eat my hat if that doesn't test positive for Asbestos.

The Good
Location, location, location! A short walk to Franklin Park-School and a short walk to the beach in the Gold Coast 'hood.
A good sized house for a family with 2 kids (but no more) with generous sized public rooms and reasonable sized bedrooms, especially the master.
Super awesome backyard that could be BBQ party central.
New Roof!
The overall condition of the house looks pretty good.
A good sized basement for storage.

The Bad
Location...its on one of the busiest streets in Alameda.
Some of the house looks a little dated. The tiles in the bathrooms and kitchen look pretty awful to me.
The kitchen is kinda tiny.
The monster forced air unit needs to be replaced and you're going to have to deal with Asbestos covered ducting.
The possible illegal partial conversion of the garage into a home office. The Alameda Building Dept. really does not like the conversion of garages into anything else and they could very well force the new owner to rip out all that stuff and convert it back to all garage.
Some knob and tube.
A mixture of copper and galv water piping.

Conclusion
To bring this house up to the standard of the neighborhood it will need some refreshing.
The kitchen will need to be remodeled and expanded. ~100k for a high end major remodel.
The kids bath needs a remodel ~50k for a high end remodel.
The parents bath too ~50k for a high end remodel.
Replace old furnace with new high efficiency unit and deal with Asbestos. ~20k.
That's over $200k in remodeling costs....for a $1.22M house....
That personally seems nuts to me....I'm not saying, 'Don't buy this house.'
What I am saying is, as you go in with your waaaaaaaay over asking offer, be aware of exactly the size of the hole you are digging for yourself.
Go in with your eyes open.


But Wait, There's MoreThrough the blog I've been approached by several strangers to review houses for them that they were seriously interested in. So, I've done a couple of 'private reviews' on a commission basis. If you think something like that might interest you please contact me through the email link in my profile.