Death of a Crab

Post by **aferguson** » Fri Jul 04, 2008 3:06 pm

i just came up with a nifty way to make a Sherman Crab that actually flails. I'm using a little hand held fan, that i got from a dollar store, as the motor.

For the rotating tube that the chains are on i'm using a tube from an old roll of tin foil that happens to be the perfect diameter.....only drawback is that it's cardboard but it is very thick strong cardboard and i think it will be fine.

I just test mounted with the hub from the fan inside one end of the tube and used my finger to support the other end and it spins beautifully.....all systems go, so far.

I am going to use the dozer blade support arms from an old tonka bulldozer as the support arms for the flail and will mount them to the sides of my sherman.

The motor i will mount on the inside of one of the support arms and then slip the flail tube over it.....the tube jam fits on the fan's hub (which is larger in diameter than the motor), so it will cause the tube to spin when i turn the motor on.

I will support the other end with something of appropriate diameter. So the motor will actually be inside the tube, at one end, thus hidden. I plan to run two wires from the motor to inside of the tank to where i will but the batteries, so they are easily accessible for changing. To activate the flail i will rig it so you turn the turret backwards (the real flails operated with the turret turned backwards), which will cause the batteries to connect to the motor.

For chains i'm going to go to a dollar store and buy cheap necklaces which are made from little chain. The only problem i haven't figured out is how to securily mount the sections of chain to the rotating tube....the best idea i have is to use little dobs of epoxy but this sounds somewhat shakey to me....any better ideas?

Anyway, when all is said and done i should have a 1/18 sherman flail tank that really flails its little chains.

MG-42 · Post by **MG-42** » Fri Jul 04, 2008 3:31 pm

* Again ,.. it would help if you posted a pic. *

* Why not try using , tiny hobby nuts and screws to hold down the flails in place ?

Mitch v MG

ostketten · Post by **ostketten** » Fri Jul 04, 2008 3:33 pm

Anyway, when all is said and done i should have a 1/18 sherman flail tank that really flails its little chains.

I hope you can post a short video of it in action once you get it going Andrew, it sounds cool, and very creative. Now all you need is a little field of Teller mines to flail away at...

pickelhaube · Post by **pickelhaube** » Fri Jul 04, 2008 3:40 pm

ostketten wrote:
Anyway, when all is said and done i should have a 1/18 sherman flail tank that really flails its little chains.
I hope you can post a short video of it in action once you get it going Andrew, it sounds cool, and very creative. Now all you need is a little field of Teller mines to flail away at...

It is the 4th of July the tiny explosions

would be cool.

Post by **aferguson** » Fri Jul 04, 2008 3:52 pm

update: i just tested it with several short pieces of string taped to the tube, to simulate the chains and it looked fabulous in action.......very scale in apperance

olifant · Post by **olifant** » Sat Jul 05, 2008 1:38 am

You might try cutting a hole in your cylinder, knotting the chain and running it through from the inside. Copper/PVC/HDPE tubing may be a better answer as it would be stronger and different materials/brands would have different IDs. If you used copper you could even dent it up a little.

I bet this looks great!

Post by **aferguson** » Sat Jul 05, 2008 5:55 am

i've already decided to punch little holes in the tube and jam the ends of the chain in them and then epoxy. I think that will be strong enough...we'll find out. The tube is less than an inch in diameter and 6 inches long so i don't know how i'd be able to knot the chain and then slip it through from the inside.

Two problems with using plastic tubing are that i need it to be exactly the right internal diameter, which the tube i have now is, and the weight. I'm worried about getting this thing too heavy so that the little motor won't be able to spin it. I'm actually even concerned that the weight of the chain will be too much for it (i need about 8 feet of chain), so i may have to use a substitute for chain. I hope not though.

The cardboard tube i have is actually very strong. It's not flimsy like a toilet paper tube but quite thick and yet very light. I can practically stand on it without crushing it, so i think it will work fine. If not, then i can always rework it with some other tube, if i can find one the right size.

Anyway, i think this should take only a few days to cobble together and will be quite fun. I plan to wear my squash goggles while playing with it in case some of the chain pieces fly off.....this thing really motors!

pickelhaube · Post by **pickelhaube** » Sat Jul 05, 2008 7:35 am

Hey Man , This is cool. Christmas is on the way. Could you please ask Santa for a camera?

VMF115 · Post by **VMF115** » Sat Jul 05, 2008 8:39 am

We need some pic's, pic's, pic's, pic's, pic's,pic's, pic's, pic's, pic's,pic's, pic's, pic's, pic's,pic's, pic's, pic's, pic's,pic's, pic's, pic's, pic's,pic's, pic's, pic's, pic's,pic's, pic's, pic's, pic's,pic's, pic's, pic's, pic's,pic's, pic's, pic's, pic's,pic's, pic's, pic's, pic's,pic's, pic's, pic's, pic's,pic's, pic's, pic's, pic's,

Panzer_M · Post by **Panzer_M** » Sat Jul 05, 2008 4:49 pm

i guess it's true..

there are no digicams in Canada.

Razor17019 · Post by **Razor17019** » Sat Jul 05, 2008 8:43 pm

How about you draw us a picture of your new creation...
If it's really good, we can post it on the fridge, like I do with my 4 year old.

General Blasto · Post by **General Blasto** » Sun Jul 06, 2008 4:31 am

Yes, a picture or three will say a thousand words or more, but will paint a better picture in my mind

A Sherman Crab ??? I am lost to figure this one out

Is it the attachment to the front of a tank that cuts weeds or tall grass or what

Da General

Stug45 · Post by **Stug45** » Sun Jul 06, 2008 5:05 am

Sherman crab video and info.

video
http://www.youtube.com/watch?v=WhJcM6BzGxw

Info

http://en.wikipedia.org/wiki/Mine_flail

grunt1 · Post by **grunt1** » Sun Jul 06, 2008 11:46 am

Since you won't get a camera (or even take one offered to you for free)... We are left to imagine your creative process only in our mind's eye...

VMF115 · Post by **VMF115** » Sun Jul 06, 2008 11:51 am

ROFLMAO

Post by **aferguson** » Sun Jul 06, 2008 4:55 pm

construction is under way....i'm having to make several compromises to accuracy due to the bits i have to work with and for the sake of making it strong enought to take the rotational forces but it will look ok.....so long as i don't hang any pictures of Sherman Crabs in the same room...

I'm using my COED Sherman as the tank; i always thought it was pretty boring and bought it loose off Ebay for custom work. Will have to repaint and put in britissh 79th armd. division markings.

Razor17019 · Post by **Razor17019** » Sun Jul 06, 2008 8:28 pm

grunt1 wrote:Since you won't get a camera (or even take one offered to you for free)... We are left to imagine your creative process only in our mind's eye...

Very nice, Grunt!

AlloySkull · Post by **AlloySkull** » Mon Jul 07, 2008 1:35 am

I really want to see this... Can we strike up a camera fund? Although I'm sure when the money gets there we'll hear about how he just got a badass new F-4...

General Blasto · Post by **General Blasto** » Mon Jul 07, 2008 5:10 am

Yes Capt.,
I agree the COED Sherman is the best one to use, it's quite boring looking and was only used(if that) in the Pacific theater

I used a COED unit to make my VC Firefly unit. I have one other COED unit and I think I will use it to make a second VC Firefly

Da General

MK · Post by MK » Mon Jul 07, 2008 7:00 am

AlloySkull wrote:Can we strike up a camera fund?

Even a cheap film camera would work, when he has it developed, he can opt to have a photo CD made. Its usually a free service for me if I get prints made.

Post by **aferguson** » Tue Jul 08, 2008 4:42 pm

making progress. Have both of the roller arms done and mounting holes made on the tank. I've mounted the motor to the inside of one of the roller arms via epoxy. The roller will now fit over top of it and rest on a spindle that i've glued inside the other roller arm.

After much cogitation i've decide to put one battery, vertically in each hatch. Each battery will rest on a metal plate that will have a wire running from the motor connected to it. The batteries will be connected to each other via a wire that runs under the top of the hull, between the hatches. So to replace the batteries i just need to open each hatch, push the wire out of the way, plop in a new battery and then rest the wire back on top of the battery....and then repeat for the other side.

To prevent the flail from continuously running i will just stick a bit of paper under one of the wires, thus breaking its connection with the battery. Not terribly sexy but the best i could come up with. Hopefully i'll think of something better.

This has been slower going than i anticipated as there have been a bunch of fiddley little problems to contend with. I do have all my chain now.....10 1/2 feet of it. Bought a bunch of 'High School Musical' pendants for a buck each...ha.

This thing better work...

kduck · Post by **kduck** » Tue Jul 08, 2008 5:18 pm

I don't know what the type of chain you're using looks like but if it's bright silver and you'd like to darken it to a duller looking finish there is an easy way to do so. You can buy a small bottle of gun blue from the sporting goods section of WM. Rusty chain would probably be more accurate but just about anything looks better than bright silver.

Post by **aferguson** » Tue Jul 08, 2008 5:58 pm

thanks but i was just going to spray paint the chains black......like the real chains were. The individual links will no doubt stick together after painting but a few flails should loosen them all up. The real chains weren't rusty after flailing as they got sand blasted pretty good and so if some of the black paint wears off a bit, that's ok too as it will leave a metallic silver look that the real chains no doubt had.

I also figured out a sexy way of activating the flail. To one of the wires that go on top of the batteries i am going to tie a piece of fishing line that has the other end glued inside the turret. When i rotate the turret to the rear it will tighten the fishing line and pull the wire over top of the battery, complete the connection and the flail will go. When i turn the turret back forward it will slacken the fishing line and the wire will be pushed forward by a thin plastic strip 'spring' that i will glue to the wire.

It seems that the real Crabs had to have the turret pointing to the rear to spare the gun from being damaged by mine explosions. So this is a realistic and simple 'switch' mechanism....heh.

Post by **aferguson** » Wed Jul 09, 2008 4:33 pm

well, i had it all hooked up today and it worked. I haven't added the chains to the rotor yet but the rotor spins just fine. The whole apparatus strikes me as being pretty shakey, however and very break-down-able, so i doubt the rotor will spin for years to come. If i get a few plays out of it i'll be happy. It will then be a nice display piece of a sherman flail tank and i'll have the memory of the rotor spinning to keep me warm...

Now the boring part of detailing and painting the tank, then i put the chains on the rotor and paint it, then i put it all together and hold my breath...

MG40K · Post by **MG40K** » Wed Jul 09, 2008 5:42 pm

Sounds very coll, please post some pics if you can, I'd love to see it.

Small Scale Military Headquarters

Death of a Crab

Death of a Crab

* Crabby idea