RattleCAD users? Let's Talk.

[trentschler]

Is there a way to change the head tube diameter from 36 mm to 31.7 mm? From what I can tell, RattleCAD generates nice miter templates, but the head tube is 36 and I've got some 31.7 tubes.

[c-cycles]

That should be no problem. I've using only 31.7 so far with RC.

Christian Kirn

[devlin]

You can double click on the tube itself in the second layout.

[trentschler]

You can double click on the tube itself in the second layout.

Ah so!

[dbohemian]

Hi David,

rattleCAD does not care about the BB-Diameter to calculate the DownTube Length.

Which Length do you want to get?

Can you explain me this on a graphic?

Thanks, Manfred

Yes, I understand that Manfred....but, you need to know the BB diameter to accurately miter the DT. I use the distance from the bottom of the DT/HT interface to the lowest portion of the miter on the BB end. I mark this dimension horizontally along the tube with a large caliper. So I take the number Rattlecad gives and I subtract the radius of the BB. I make the DT miter, then use that as a reference to mark the length of the DT so that I can put the edge of a hole saw right on the line I mark. So in this picture I would take 588.72mm and subtract 19.05mm for an english BB. I would mark along the length of the tube (not diagonal as I have shown) and that mark is always too long for me. Manfred.jpg

[RyanDelavelo]

I'll try getting a screenshot later (running Linux is sometimes a bit of a drag!)

[EricKeller]

I'll try getting a screenshot later (running Linux is sometimes a bit of a drag!)

alt-printscreen takes a screenshot of the currently selected window on most window managers. Not quite as nice as the windows snipping tool. There is an app called "shutter" that works like the snipping tool, I just installed it on my ubuntu system, works great.

I want a view of fork crown clearance like the stay clearance view on bikecad. Brent doesn't seem interested in adding it. Does Rattlecad do that?

[RyanDelavelo]

Thanks Eric, good tips :-).

David beat me to it today and describes the problem I've also encountered perfectly. All other measurements that RattleCAD lists in purple seem fine otherwise.

[CarbonNeutral]

You also can't pdf out the mitre templates when running RCAD on a Mac. You press the button and nothing happens.

[fred_stmk]

You also can't pdf out the mitre templates when running RCAD on a Mac. You press the button and nothing happens.

Hi,
do you have ghostscript installed?


Manfred Rosenberger

[fred_stmk]

83860-rattlecad-users-lets-talk-manfred_query.jpg


Manfred Rosenberger

[devlin]

For me the DT will have two different lengths depending on whether you are fillet brazing/TIGing to the outside of the BB shell or running the tube through the lug socket. So for me the length shown in purple is fine as I'd then take the inside radius from the I.P. for a lugged BB shell and mark my mitre after I had mitred the HT end.

[dbohemian]

For me the DT will have two different lengths depending on whether you are fillet brazing/TIGing to the outside of the BB shell or running the tube through the lug socket. So for me the length shown in purple is fine as I'd then take the inside radius from the I.P. for a lugged BB shell and mark my mitre after I had mitred the HT end.

Yes, that is true Sean but even that mark is too long....Although some like to run a little extra inside a lugged BB shell.

[fred_stmk]

83860-rattlecad-users-lets-talk-manfred_query.jpg

and

Yes, that is true Sean but even that mark is too long....Although some like to run a little extra inside a lugged BB shell.

Hi David,

I fear / I hope this is a geometric problem.
can you please explain the question marked length?
.. and which length does it have?

Manfred Rosenberger

[devlin]

Ahh.. I think there is a slight disconnect on a few levels here. I was fiddling with it now at work and one thing I noticed was the DT on the standard template is 31.8 at the TT end and 34.9 at the BB end. I would double check all your tube diameters before any dimensions taken from the drawings.

What Dave was trying to illustrate is the two marks he would make on the tube for cutting or template line up. He is looking for a dimension that goes from the center line tip of the DT/HT mitre to the centre line at 90 deg for the DT/BB mitre that is parallel with the tube. This is for a fillet brazed BB I would also like to see an option to switch to a lugged dimension as well which is about 3mm longer.

Is it possible to have in the config box a list of all the dims shown and an on/off selection?

DT dim.JPG

[devlin]

Yes, that is true Sean but even that mark is too long....Although some like to run a little extra inside a lugged BB shell.

I just noticed as well the dimension is going from the outside edge of the tube to the centre line. That is going to add you 1+mm. If the purple dimension was parallel to the tube centre line and then to the BB centre point you should get the right number.

Edit: Actually it's only about 0.2mm but it still should be a dimension parallel to the centre line

[RyanDelavelo]

With reference to Sean's diagram abouve wouldn't it be more benificial to know the distance between the 'tip' of the BB/DT mitre, and the 'dip' of the HT/DT mitre? That's what I was seeking. So, the length of the tube directly along it's bottom edge.

[Tristan]

alt-printscreen takes a screenshot of the currently selected window on most window managers. Not quite as nice as the windows snipping tool. There is an app called "shutter" that works like the snipping tool, I just installed it on my ubuntu system, works great.?

Linux Mint and Ubuntu Mate both ship with https://en.wikipedia.org/wiki/GNOME_Screenshot - it's a really tidy tool and a bit nicer to use than Shutter (imho.) If you're running something gnome-based it should be in the repositories. (ie run this from a terminal: sudo apt-get install gnome-screenshot)

[Herr Stahl]

I have just finished a fillet brazed 29er using rattlecad and its miter templates.

Re your example, could the following approach work?

1. Draw center line on DT

2. Attach DT/HT miter template

3. Measure 588.72 - 28.45 = 560.27 from DT/HT along the center line and mark this point

4. Transfer this measure on the other side (180°) of the tube. (Alternatively do this transfer on the mitre template: transfer ST/DT mitre bottom point 180°)

5. Attach BB/DT/ST miter template

6. Show the tube who is boss

I have designed a couple of frames in rattlecad and am grateful to Manfred, who is doing a great job in developing and maintaining this tool.

Thanks,
Peter Dalhoff.

[devlin]

With reference to Sean's diagram abouve wouldn't it be more benificial to know the distance between the 'tip' of the BB/DT mitre, and the 'dip' of the HT/DT mitre? That's what I was seeking. So, the length of the tube directly along it's bottom edge.

My personal preference would be for the working dimensions ie. the ones that fixed the frame geometry. So that would be the bottom of each mitre. These are the marks where the cutter or template is set to. There are multiple ways of doing it really and it depends on how you set everything up and work in the workshop.

Yes Manfred does a huge job making this work. Much appreciated for sure.