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Mechanics and Construction => Mechanics and Construction => Topic started by: MaltiK on March 02, 2009, 11:09:00 AM

Title: Strong Metal Rod for the job?
Post by: MaltiK on March 02, 2009, 11:09:00 AM
You see in this picture the mounting holes:

(http://lh3.ggpht.com/_-2NNkO8FaRc/SacsgLKzkHI/AAAAAAAAAMo/8voNgC5FtYE/s640/motor3.JPG)

I am looking to thread two metal rods through each of the motors on both sides, and both holes (two). Through this chassis:

(http://lh3.ggpht.com/_-2NNkO8FaRc/Sark6_cB0-I/AAAAAAAAAOg/XUIv_f4aE1I/s640/HPIM2546.JPG)]

I will be drilling holes on the vertical slabs for the rod to be threaded through.

One rod is closest to (less) than .472"
and the other is .276"

I did a search and found onlinemetals.com via amazon

I got these two pages:

http://www.amazon.com/s/qid=1236013657/ref=sr_st?rs=16414231&page=1&rh=n%3A16310091%2Cn%3A16310191%2Cn%3A16414131%2Cn%3A16414231%2Cp_item_length_derived%3A24+inches%2Cp_item_thickness_string-bin%3A0.25+inches&bbn=16414231&sort=price (http://www.amazon.com/s/qid=1236013657/ref=sr_st?rs=16414231&page=1&rh=n%3A16310091%2Cn%3A16310191%2Cn%3A16414131%2Cn%3A16414231%2Cp_item_length_derived%3A24+inches%2Cp_item_thickness_string-bin%3A0.25+inches&bbn=16414231&sort=price)

http://www.amazon.com/s/qid=1236013657/ref=sr_st?rs=16414231&page=1&rh=n%3A16310091%2Cn%3A16310191%2Cn%3A16414131%2Cn%3A16414231%2Cp_item_length_derived%3A24+inches%2Cp_item_thickness_string-bin%3A0.375+inches&bbn=16414231&sort=price (http://www.amazon.com/s/qid=1236013657/ref=sr_st?rs=16414231&page=1&rh=n%3A16310091%2Cn%3A16310191%2Cn%3A16414131%2Cn%3A16414231%2Cp_item_length_derived%3A24+inches%2Cp_item_thickness_string-bin%3A0.375+inches&bbn=16414231&sort=price)

Each of these must be really hefty.
I already contacted OnlineMetals.com and they said they didnt have any engineers that could help me.

These rods together must be able to support over 150lbs via suspension on both ends, so it is most likely, that if it breaks at all it will be the middle.
.25 and .375" rods
Title: Re: Strong Metal Rod for the job?
Post by: pomprocker on March 02, 2009, 11:14:29 AM
I've bought a lot of construction materials from drillspot.com they are amazing, they use grainger as a distributor for some of there stuff so it gets to your house next day.
Title: Re: Strong Metal Rod for the job?
Post by: Razor Concepts on March 02, 2009, 11:15:03 AM
You can put a strong metal tube around the middle of the rod to make it stronger.
Title: Re: Strong Metal Rod for the job?
Post by: MaltiK on March 02, 2009, 11:51:05 AM
I've bought a lot of construction materials from drillspot.com they are amazing, they use grainger as a distributor for some of there stuff so it gets to your house next day.

The manufacter isnt the problem, the choice of material is

Quote
You can put a strong metal tube around the middle of the rod to make it stronger.

Good call! well do!
Title: Re: Strong Metal Rod for the job?
Post by: paulstreats on March 02, 2009, 08:28:48 PM
Couldnt you just use nuts and bolts? rather than long metal rods. presumably they were just mounted to the wheelchair with nuts and bolts so they would have supported a persons weight easily.
Title: Re: Strong Metal Rod for the job?
Post by: MaltiK on March 03, 2009, 01:59:03 PM
Couldnt you just use nuts and bolts? rather than long metal rods. presumably they were just mounted to the wheelchair with nuts and bolts so they would have supported a persons weight easily.

You are right, but I am looking to overkill it. The wheelchair is designed to support 150~lbs, but the chassis was made of some metal, and I used wood, so I must use a support system able to support a greater weight, rods.
Title: Re: Strong Metal Rod for the job?
Post by: madchimp on March 03, 2009, 06:32:40 PM
I don't think rods are the answer. I would go with bolts and if you are worried about them pulling through the wood use fender washer or even make a small metal plate to act as a washer. If you are worried about the stability of the sides use some diagonal bracing.
Title: Re: Strong Metal Rod for the job?
Post by: MaltiK on March 03, 2009, 07:36:07 PM
Awww well I already ordered the rods, with aluminum tubes, so if they break, their is nothing I can do.
Title: Re: Strong Metal Rod for the job?
Post by: Soeren on March 04, 2009, 12:33:40 PM
Hi,

Use ball bearings close to the wheels to carry the weigth.

Why not just make something that fits into the assembly like they have originally been used?
Title: Re: Strong Metal Rod for the job?
Post by: MaltiK on March 04, 2009, 02:45:23 PM
Quote
Use ball bearings close to the wheels to carry the weigth.

I was going to use one caster wheel
Quote
Why not just make something that fits into the assembly like they have originally been used?
thats what i plan on doing with the rods :)