SAE equivalent parts / adapters

[jesse]

This thread is for buying parts in the USA. Metric pipes for PVC and brass (copper?) are not sold at Lowes.

Adapters/custom parts for inch-based pipe is also welcome.

[Quentin Harley]

Hi Jesse,

If you US guys can supply me with commonly available close matches to the metric parts I use, we would do and SAE branch of Morgan on github.

This should make your lives a bit easier…

[jesse]

The sizes are usually measured by inner diameter. Common sizes are 1/2 inch, 3/4 inch, 1 inch, 1 + 1/4 inch, 1 + 1/2 inch. There was one piece of pipe that fit part #1 but not passed the lip.

Here are some PVC pipes from a hardware store.

http://www.lowes.com/Pipe-Fittings/PVC-Pressure-Pipe-Fittings/PVC-Pressure-Pipe/_/N-1z0zp1h/pl?Ns=p_product_qty_sales_dollar|1#!&Ns=p_product_price%7C0&page=1

For copper, I found the outer diameter was 16 mm and 23 mm (instead of 15mm and 22mm). The clerks said that brass pipe is not normally sold for plumbing anymore (in the USA).

[Quentin Harley]

Yes… Brass was a slight doccumentation mistake on my side. It should be plain old copper plumbing piping.

So, 16 and 23. I will start on the SAE branch sometime today.

[jesse]

Is it OK to use 5/16 inch threaded rod?

5/16 inch == 0.3125 inch == 7.9375mm

[nethack]

I’m building one (albeit with mostly metric parts) and I would say that the 5/16″ rod would work IF you ensured that the nuts fit correctly into the printed parts and the tubing. One issue I ran into was that the M8 nuts are not force fit in the 15mm tubing. I used superglue to make them stick (epoxy would probably be better). I would check and see how 5/16″ Nuts fit in the various parts.

I’m sure Quentin will have some input, also.

don

[jade39339]

Also, I’m wondering what the pitch of the thread should be on the 5/16 thread, they have 5/16-18, 5/16-24, and 5/16-32, which I’m taking is the pitch size. I was going to use 5/16-24, would that work or do I need a finer pitch, such as 5/16-32?

[jesse]

Quentin said he used coarse threading

[ajacocks]

Has a US/SAE branch been started, yet? I don’t see it in the repository.

[Quentin Harley]

There is no US branch yet. There are a couple of US builders working on their Morgans already.

If only somebody brave in the US would fork Morgan and create a US/SAE branch… Just thinking aloud here…

😉

[jesse]

I’ll try since the OpenSCAD files are available

[hoff70]

Hello all!

I am currently working on a Morgan in the US as well. The standard pipe available here is 1/2″ (Mine is 15.8mm OD) and 3/4″ (Mine is 22.3mm OD)

I got excited and printed my Z arms and managed to file the 1/2″ pipe into a reamer and opened up the holes for a really good snug fit. I also printed the 22mm pulley and will try to ream it as well.

I’m not good with CAD but I have a friend who is going to assist me with adapting the parts to hardware available in the US. Mainly the copper tubes and using 5/16″ threaded rod instead of 8mm.

I am currently going through the parts figuring out what parts need modification in order to let him know. If someone else modify’s the parts first then GREAT!

I’m printing my Morgan on a Rostock in case anyone is wondering…

THANK YOU MR HARLEY FOR YOUR FINE WORK! I am VERY excited about building one of your machines! Congrats on the GADA prize sir. It is well earned. You are one uber clever dude and a HUGE inspiration!

Jon from Georgia

[Quentin Harley]

Thanks Jon

Be sure to send some pictures of your machine when you are done!
Q

[hoff70]

I am taking pictures as I go along. I got impatient and printed the metric spec parts and modified them with a homemade reamer:

I also used the same method on the holes in the Z brackets as well. Just thought I’d share this with other people who are as impatient as I am…

There are a couple of very generous people over on letsmakerobots.com who are working on modifying the files to US spec so we americans can buy the long parts locally!

[Quentin Harley]

I ream them myself, even when printing metric and using on metric pipe. I use this:

Like your reaming tool a lot. It is often the simple tools that work the best.

[hoff70]

Here are some of the modified parts:

https://www.dropbox.com/s/a8nezh3l9iok918/modded%20parts.zip

They haven’t been tested so let me know if anything looks wonky! The Z arms still need to be addressed so I’ll post them once sorted.

Thanks to K120189 (Kevin) over on http://letsmakerobots.com/

He’s also the creator of BoB the bi-ped:

http://letsmakerobots.com/node/35865

Which is a really clever little printable robot that walks around!

[hoff70]

Here are the z arm stls

https://www.dropbox.com/s/bwmdg5kos8f9jw4/bed%20arm%20right%20imperial.STL

https://www.dropbox.com/s/fsselpyb9bodmd6/bed%20arm%20left%20imperial.STL

[donpdonp]

Is there any problem with this approach:

instead of 15mm pipe, use 5/8″ (15.8mm)
instead of 22mm pipe, use 7/8″ (22.2mm)

Then get a 7/8″ step drill bit like the 22mm bit posted in this thread.

Without any modification to the printed parts, use the slightly larger step bit to widen the parts that connect to the 7/8″(22.2mm) pipe. It appears none of the bearings depend on the pipe being exactly 22mm (the 6805 has a 25mm ID) and the printed parts I would think could stand to be widened by 0.2mm without modification.

Is there anything I’m overlooking? Thanks.

[Quentin Harley]

Exactly right!

This is the way we do it even using the metric parts, since the prints end up slightly tight anyway.

When I started making Morgan I tried to make it as tolerant as possible to different hardware products available.

Print the parts with 3 shells (perimeters) to give you more to dig into.

[evamvid]

Have these been tested yet?

[Quentin Harley]

Yes

[evamvid]

I’m going to try to make a version that is compatible with SAE pipes but metric hardware. The reason for this is that in the US, it’s pretty easy to get the required hardware, either from physical stores like Ace Hardware or Fastenal, or from McMaster-Carr.It’s the same price for metric or SAE I prefer metric because it just makes more sense, and is much more practical than SAE. However, the metric pipes are more expensive than the SAE ones, and as far as I know the only place to get them is McMaster-Carr. I don’t know when I’ll have time to work on this, though.

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