Monitor Steam Engine

[zeeprogrammer]

I see you are still learning Alibre
Not me. I'm using CubifyDesign. The drawing was from Jason. (Is that what you were referring to?)
Have you considered drawing a partial cross section of the part and then revolving it?
Yes. I've done that for several parts.

BTW did you understand the dimensions
Thought I did. But your emoticon has me worried 
PS your Cubify is no good to us
Well gee. That's too bad. 

Regarding Alibre...I find it confusing figuring out what's available. GeomagicDesign? Xpress? Pricing as well.
CubifyDesign works in a similar way so I don't think I'd have any problem switching.
CubifyDesign cost me $200 a few years ago and does everything I wanted save a couple or three things...
a) It doesn't seem to support animating a follower and cam profile. Not an issue now...but someday.
b) I don't think I can animate a clock escapement. Again...not an issue now.
c) I haven't figured out how to create a tree of sub-assemblies. Also not a biggie. But one has to be careful. If a sub-assembly has moving parts and that sub-assembly in put into another assembly, then all moving parts become fixed. Have to wait until final assembly to insert moving parts.

But then I haven't done any searching for possible plug-ins.

The ability to animate is pretty important to me.

I would have no problem switching to another CAD. However, I would balk at anything more than about $400 and won't consider anything that dies after a set time period (i.e. subscription).

What is the specific name/version of the program you are using?

[Jasonb]

Zee that reply was aimed at Jo

My earlier Alibre won't open newer Geomagic or Cubify files, thought you also has Alibre

I know you can understand imperial

J

[zeeprogrammer]

I know you can understand imperial

Yep. Metric too. And then there's the unpublished measurement system I've often used for many of my parts...zee-eyeball. 

[Jo]

Sorry Zee I missed it is Jason that has not progressed to rotating things 

Jo

 

[zeeprogrammer]

Just fooling around...

The dimensions on the nipple aren't right.
And several questions came to mind but I'll save them for later.

[Jasonb]

Sorry Zee I missed it is Jason that has not progressed to rotating things 

Jo

 

You will be pleased to know that I did revolve my balls

On other disadvantage of drawing a section and then revolving is that if the part is threaded or drilled you won't get the thread call out, hole dia and depth automatically put on the drawing so have to manually add them. By doing them as you draw the part they will appear on teh drawing.

[zeeprogrammer]

Usual way is to make your nut first as you can't adjust the tap and then cut the male thread to suit

Meant to comment on this. Thanks.

Still waiting for some taps and metal. 

You will be pleased to know that I did revolve my balls

Ouch

[zeeprogrammer]

Still waiting for metal. 
In the meantime, I had some stainless steel shafts of needed diameter (from a previously failed non-metalworking project).

This is the Valve Rod End Pin.
Simple turning.

I have only one nut and it's the wrong size so I took a run at making a 5-40 nut as well as a washer.
The washer came out fine - maybe a little thick. I zee-eyeballed it.
The nut is lousy. I don't think I'll make any more until I gain sufficient experience and/or figure out how to round them off.



And assembled up.



I'm not happy with the thickness of the nut (or maybe the length of the pin's thread). I want the pin to portrude maybe a 1/32 past the nut.
Going to order some nuts (and maybe washers), measure the stackup, and redo the end pin. The nut I made is 3/32 thick. Maybe a 1/16 is best?

I've not machined stainless steel before. It machined well and die-threading was a breeze.

But I'm still not happy with the finish I get on stainless or any steel for that matter. I do okay with aluminum and brass.

I looked into feeds and speeds but find it pretty noggin-knocking. Besides, I have no idea what the spindle speed is or feed rate. It's all done by zee-feel and zee-hearing.

Any tips? Is faster spindle speed needed?
Is there some chart that's more appropriate to my hobby pursuit (i.e. not industrial)?

I was using an index tool (which may be in poor shape and no doubt doesn't help). And cutting oil.

[Tennessee Whiskey]

Boy did you leave the door wide open with the statement on nuts  , but nope, not gonna do it , let's just say that you need a lesson from Dave Otto, tell him Vern, best darn looking nuts in town . I am thinking you will get better finishes by exploring other cutting tool options. I'm going to try and attach a good "guide line" from LMS. Notice the difference in the speeds for HHS vs. carbide. Most home shop machines just aren't fast enough spinners for carbide in the "softer" metals we cut IMHO. I have been using the Warner HHS stuff I picked up at CF and like it so far.  Since I've never been good at grinding a bit,  this gives me HSS with insert ease of use.  Anyhoo,  pin looks great;  nut  , nope not a gonna do it  .

http://littlemachineshop.com/Reference/CuttingSpeeds.php

Cletus

[Jo]

Nuts: someone told me off for having a fascination with the details of both my nuts and their studs  .

Zee what length are your nuts? It is important to get the length of your nuts correct relative to the diameter of your thread. I've got a look up chart for when I do my nuts and it also provides the necessary nut allowance for my studs so that they fit just right 

And have you thought about the shape of your nuts: Double or single chamfered, single always looks better on a washer but double is necessary if you have no washers and don't want them digging in.

Jo

[Jasonb]

It's not only the length of the nuts but also the hex A/F that affects the look. A lot of commercial metric and US nuts have a large hex relative to the thread diameter, look back at Brain's rocker arms on his opposed twin for an example, I assume these are stock nuts and then compare them with mine on the same engine. Looks like your nut is based on a commercial one too

If you use Jo's BA chart and pic a matching diameter thread eg for 5-40 use the 5BA nut sizes you won't go far wrong with the look of your nuts

[zeeprogrammer]

Thanks Eric. I'd come across that chart when I was looking around the other day. I'll study on it more. I also need to figure out how to tell what speeds I'm running at...or maybe build a cheap tach.

Thanks Jo and Jason. When I started on this I put together a chart to convert BA threads and nuts to imperial. I did some searching around to get measurements of commercial nuts. The one you see was for the 1/8" threads which I took to be 5-40 or 5BA. I don't know what's typical for nuts in modeling and tried to use something that 'looked' right.

The dimensions for this nut was 1/4" across flats (6.35mm - slightly larger than Jo's chart) and 3/32" length (2.38mm - slightly smaller than Jo's chart).

Personally I think it's too thick.

As for chamfer...I was originally going for double chamfer. I simply think it looks better and more usual. You might not tell in the picture but I slightly chamfered one side. But I think my method is lousy, it turned out lousy, and I didn't do the other side.

Thanks Eric for the reminder on Dave's nuts. I need to review both his and Jo's nut making methods.

There's quite a few nuts in this project (at least to me). So I may get some commercial ones. I think they're fairly prominent in the model and I don't want my poor nuts to detract.

Thanks all. Very helpful.

Oh...Jo...what is 'nut allowance'? Is that the amount of stud needed? i.e. the length of the nut plus some amount that the stud sticks past the nut?

[Jasonb]

Personally I think it's too thick.


As for chamfer...I was originally going for double chamfer. I simply think it looks better and more usual.

An interesting choice of word - "Usual"  We are used to seeing commercial nuts which are indeed flatter and more often than not double chamfered which is often due to the way they are made by stamping them out.

Look at any photos of old steam or gas engines and you will find the nuts are turned, chamfered on one side and generally of a taller nature and they were quite usual at the time.

If you are going to buy commercial nuts look at what you are getting, here we can get say M3 nuts from hundreads of places at very cheap prices but they are like the left hand one in the photo below but there are a few suppliers about who make turned ones that look correct on a period engine like the one on the right

I took this photo to illustrate the same thing on another forum, the nut on the left is a mass produced stamped out one, think it was 1/4" BSF which is 26tpi, can't remember the middle one but the one on teh right is what I made and looks far more in keeping with teh period.

[Jo]

The dimensions for this nut was 1/4" across flats (6.35mm - slightly larger than Jo's chart) and 3/32" length (2.38mm - slightly smaller than Jo's chart).

Personally I think it's too thick.

The thickness of the nut is based on the tensile strength of the material and depth of the thread (bigger studs = more thread depth as a rule). If your nut is not thick enough you cannot torque the nut up to get the full holding strength of the bolt/stud and if you do its threads will strip  .  In addition you don't get the full width of the nut of threads providing the holding force you lose strength where they countersink either side of the nuts so you end up with less distance of threads relative to the thickness of the nut. If you want a rule of thumb then the nut should be about the same thickness as the diameter of the thread (larger ones fractionally less, smaller ones fractionally more  )

(Don't forget the rule of thumb that a stud should be threaded into the material by one and half times the diameter of the stud so that it is capable of holding at the full tensile strength of the material)

Oh...Jo...what is 'nut allowance'? Is that the amount of stud needed? i.e. the length of the nut plus some amount that the stud sticks past the nut?

When you are working on your studs it is that extra bit of length so that their nuts go on and leaves the required one and a half threads  (the bit of the stud that is rounded over plus a full thread to insure they are securing on fully formed threads both on the nut and stud)

Jo

[sshire]

Zee
Once Dave Otto explained nut making, I've generally made my own. That said, on small nuts, I've been very happy with the look of American Model Engineering Supply's fasteners. The nuts are to the "Heavy Hex" spec and just seem to look right.

http://www.americanmodeleng.com/id41.html