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View Full Version : HB-MKVI In devlopment, need suggestions


Tytus Gerrish
05-22-2004, 10:02 PM
ok, so im at it again im going to disasemble the MKV verson of my hoverbot and begin construction of a new one

ihis will be another of a long line of attempts to build a practical hoverbot

the concept is simple i make a hovercraft platform and then use things from the edu-bot kit Woops, I mean Robovation kit to moblise it

here are the materials i have used before...

Glad bag
Coffiecan lid
fisher price motor
toy helicopter rotor
aluminum sheet metal fan blades
Victor 883
Isaac16
hirec deluxe servomotor
4 and 11/16" muffan fans
24"x24" plastic sign material
duct tape
steel nuts and bolts
k-nex
14.4 Volt Drill batery

i now have 6 muffinfans avalable a sisable sheet of 3/64" aluminum sheet metal.

if you search this site you can find older versons of my hoverbots Most Bearing designations MK-I through MK-V

i would like sugestions and new ideas of building my new machine

so far all models have been able to create a sufficent air cussion to support their weight almost frictionlessly on...

Calm Water
smooth concrete
wood floors
linolium floors
and some other flat surfaces

they have however not been capable of creating a sufficent air cussion on the following

Asfault
roughj concrete
carpet
sod
dirt
sand
slightley rough seas (Disaster)

my propler has also always been insufficent in utalising the power of the fisher price motor my problem has been giving the blades witch are made of aluminum sheet metal enough surface area without making the diameter too big so that the motor must be moubted high, witch causes a sort of tourking action with the thrust its like pushing a box across a floor from the top compared to pushing from the center or bottom, it tips over, in the cace of a hoerbot, drives the front section of the skirt into the ground

well, i await your suggestions and opinions, espeocaly if anyone has expierence in hovercraft or propler desing

sanddrag
05-22-2004, 11:26 PM
Well, this may be a bit out of line from what you were thinking but what about using an RC car or airplane nitro engine? I think that would be pretty cool. For propellers check your local hobby shop for ones used on RC planes. They come in all different sizes and pitches and are pretty cheap.

At a garage sale today I saw a 3HP verticle shaft engine lawnmower for $5. I didn't buy it because I couldn't think of anything to do with it but hey, what about a really big hovercraft? Like one that you could ride on. Then you could get a horizontal shaft engine to propell it.

suneel112
05-22-2004, 11:37 PM
that's pretty cool. I tried making an unofficial one during the build season. I connected two alligator clip wires to a 14.4 V battery to a 4" muffin fan. I had some problems, because the alligator clips (which were metal and unshielded), touched and a wire burned, pretty badly. I don't think i'll work with circuits again. :(

Anyways, about the K'nex thing, its great if you can get it to work with other devices. I have played with K'nex for about 11 years now and I have had a lot of trouble making it work with other devices, such as coffee cans, etc. Since the K'nex rods and connectors are not of a uniform length (that is a rational number, in inches or centimeters), it is very hard making it work with objects that have rational numbers of lengths. Congratulations!!

P.S. don't use alligator clips!!!

Max Lobovsky
05-23-2004, 02:35 PM
I've had experience with electric RC airplanes and hovercrafts, so here is some advice:

1. In general, i believe hovercrafts use about 1/3 of their power for lifting and 2/3 for pushing, that's just a rough idea of how much wattage to use for each.

2. Defenitley don't make your own props if you can help it. I'm sure you will get a huge improvement by using RC air plane props. RC plane props usually have a designation like 5x5 which is diameter x pitch where pitch is the distance the propeller would move through the air if it completed one full rotation and there was no, for lack of a better word, slippage. Because you are going to be operating at much slower speeds than most RC planes, you will probably want the lowest pitch and the highest diameter you can find. Lower pitch props higher diameter props tend to give highest total force (but they have lower top speeds...). I understand you have a problem with having too large of a diameter prop, so

3. You can try angling the motor down so that it balances out the torque-ing effect or you can try using two or three smaller motors with smaller props. Actually, even better than those ideas is probably to have more lift in the front of your hovercraft to compensate for the torque.

4. I don't know what your total weight is, but if you are looking to cut some, im sure you can cut off the outer parts of of the muffin fans and just make a simple sheet metal tube to use as a duct.

Astronouth7303
05-24-2004, 06:51 PM
Once I saw a RC hover in a store. It seem'd to work fairly well, and possibly worth looking in to for hacking. Just a thought. (I have this >< much expierience with RC stuff like this)