# Imperial sizing for Mendel parts

Posted by Katai
 Imperial sizing for Mendel parts March 28, 2010 02:45AM Registered: 12 years ago Posts: 30
Has anyone successfully put together a Mendel using Imperial measurements for parts? I'm having a ton of trouble finding metric parts here in Arizona, and when I do, they're tons more expensive.

The nuts and bolts I can find (but as I said, expensive), but I can't seem to find the threaded rods at all. The people at every hardware store tell me that I'd pretty much have to go to a mill to get metric rods. So basically, I'm stuck looking online for this stuff, and that's really expensive as well.

So I was wondering if anyone has any luck in this department. If I do try to use Imperial parts ( using a 5/16" in place of M8 for instance), is there anything I should really take into consideration for the most success?
 Re: Imperial sizing for Mendel parts March 28, 2010 10:00AM Registered: 13 years ago Posts: 199
I think the only thing you have to do differently is the "steps per mm" setting on the Z axis.

I've already bought 5/16" threaded rod, nuts and washers for my Mendel frame. As soon as I get my MakerBot to print larger objects like the vertices without warping I'll try it out. I don't expect it will be a problem.

I found several "Metric/English" conversion tables on the internet. Here is what I have for conversions of the Mendel fasteners:

M3=#4 M3x20mm = #4x3/4"
M4=#8 M4x16mm = #8x5/8" M4x40mm = #8x1-3/4"
M5 Mudguard 20mm Washer = #10 Fender Washer
M8=5/16"
 Re: Imperial sizing for Mendel parts March 29, 2010 04:56PM Registered: 14 years ago Posts: 106
Here is a length reference:

You will need
five (5) 6' 5/16-18 threaded rod
three (3) 3' 5/16 smooth plated steel rod

Here are the approximate inch lengths if you are like me and don't have a metric tape measure:

Bar     Name    ΓΈ (mm)  Type         mm    Inch Exact Inch Approx    Qty
A       Stud-fraM8      Studding     440   17.32283   17" 5/16       2
B       Stud-fraM8      Studding     370   14.56693   14" 9/16       6
C       Stud-fraM8      Studding     294   11.5748    11" 9/16       4
D1      Stud-z-bM8      Studding     355   13.97638   14"            2
D2      Stud-z-bM8      Studding     418   16.45669   16" 15/32      2
E       Stud-z-lM8      Studding     330   12.99213   13"            2
X       x-bar           8Bar         495   19.48819   19" 1/2        2
Y       y-bar           8Bar         406   15.98425   16"            2
Z       z-bar           8Bar         330   12.99213   13"            2
J1              ~8      Scrap/st     290   11.41732   11" 7/16       1
J2              ~8      Scrap/st     234   9.212598   9" 7/32        1
J3              ~8      Scrap/st     157   6.181102   6" 3/16        1

Edited 1 time(s). Last edit at 03/29/2010 04:58PM by jeffpark_.

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 Re: Imperial sizing for Mendel parts April 14, 2010 04:00PM Registered: 12 years ago Posts: 30
Just FYI for anyone who comes across this.

I tried using #8 bolts in place of the M4 bolts. The problem is, if you're using the specified bearings, that won't work. The #8 bolts are slightly too big to go through the bearing. The solution is to either get different bearings (I'm not sure which ones you would use), or go with the #6 bolts. The fit is slightly loose, but it'll fit through the bearing.
 Re: Imperial sizing for Mendel parts April 14, 2010 05:32PM Registered: 12 years ago Posts: 52
I would go with the #6 bolts, then wrap the bolts with something to take up the space.
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