Beginner stuck on what should be simple .......but isn't

[peter_e_stokes]

Hi and thank you for reading this.  I am a beginner with Fusion and CAD in general so am working through tutorials and slowly improving.  I have 3d printed a few crude things as I find learning through a project helps validate training.

I decided to make a rest for a fishing rod which screws into the top of a bank stick.  I am 90% there but am stumped by how to get the male threaded portion made.  In theory its simple as just use the insert thread tool, but the thread I need isnt there (3/8 BSF, 20 tpi).  I have googled extensively and mostly just land back on the thread tool.  I have seen references to changing an xml file? but dont know where to find it or how to do it.  I also installed a tool I found but cant seem to find that! (I am on a Mac and still struggling with switching over from Win 10).

Can someone point me to a resource on how to get Fusion to do the BSF thread?  or if you have the xml file, and are willing to share (and tell me where to put it!) that would be great.

Any help greatly appreciated.  Temporarily given up on it and decided to make a custom phone holder for my phone and car!

[Bjanders]

I had a quick look, and it certainly looks like they don't have that thread, although it seems to be fairly standard. Maybe there's a better solution, but have a look at https://www.autodesk.com/support/technical/article/caas/sfdcarticles/sfdcarticles/Custom-Threads-in-...

It would help if the title of your post actually described the problem, for example "How do I create a 3/8 BSF, 20 TPI thread?".

[g-andresen]

Hi,

maybe @MRWakefield  can help?

günther

[Warmingup1953]

Will you 3D print or lathe machine it? 

[MRWakefield]

Thanks for tagging me @g-andresen .

I've attached a Whit form thread file which you'll hopefully find useful. FYI the diameters in thread files are usually set to the mean of the tolerance limits. However, for this Whit form thread file I've set the minor diameter for each external thread size to the max size allowable, otherwise Fusion fails to model the thread (due to there being not enough space to fit the root rads). I've not checked that every size works so it might fail if you use it for a different size.

Here's a screenshot from Fusion showing a 3/8 in - 20 BSF:

I don't use MacOS so I can't help you there but the link that @Bjanders posted should help.

If you have any problems just let me know.

Hope this helps.

[peter_e_stokes]

Hi,  Thanks for this, I will be 3D printing in PETG on a Bambu labs A1, How would I convert object (or Body) to a Male thread (sorry should have said earlier). 

[peter_e_stokes]

Many thanks for this, I will try and get my head around it this week.  Things are getting a bit clearer now.

[peter_e_stokes]

Thanks for this, yes I think you are right about my post title, I was feeling very frustrated at the time so it was accurate even if not helpful.

[MRWakefield]

You're welcome. Don't forget to let us know how you get on with it or if you need any further assistance.

[peter_e_stokes]

Hi, well so near yet so far!

I found a tutorial on how to upload the xml and have Fusion recognise it (yaay) so selecting the 3/8 BSF setting gets a result that is so close to correct but will only do a turn and a half before locking up.  I tried each of the class settings but not much changed.  looks like thread pitch is not quite right (see photos) but I am not sure what to adjust to sort it.  I am presuming it will be something in the xml file.

Thanks for taking a look

This is what Fusion produces with the 3/8 BSF settingThis is what the correct thread looks like (manufactured part)How the two threads compare

[MRWakefield]

Ok, so it looks like the manufactured part isn't 3/8" - 20 BSF. I suspect that it's M10x1.25.

EDIT:

You might also find this post useful. It explains how to adjust threads for 3D printing. Hope you find it useful.

[peter_e_stokes]

I tried an M10 x 1.25 but that didn't work either, according to Google etc the thread in a "bank stick" and other fishing items like landing nets are generally 3/8 20tpi (although new sizes are coming out from other vendors) pretty confident this is 3/8 though I have also seen it written as 9.52mm x 1.27 pitch (odd that 1.25 tool fits so well!).  It may be that I need to do an offset but gonna have to work that one out.  Seems when Fusion does an update it forgets where your xml files are on a Mac and mine just updated so going to have to start again.  Thanks again.

[MRWakefield]

Bear in mind that 3D printed threads tend to need 'adjusting' (hence the reason for the post I linked to). If you don't, then they very likely won't fit. So, if you tried a 3D printed M10x1.25 then this would be a very likely reason it didn't fit. No one uses BSW and BSF any more for new products, they're still around only as support for old equipment etc. It might be that some are still using 3/8" BSF so they fit old nets/handles but I'd be quite surprised if they were. They could be 3/8"-20 UN but because that 1.25mm thread gauge fits so well I really do think it's M10x1.25 (mind you the difference is only 20 microns per pitch). If you can get hold of an M10x1.25 bolt/screw or screw plug gauge to screw into the mating part then this would help confirm what it is (or isn't!).

Yes, 3/8" = 0.375" = 9.525mm and 20TPI = 0.05" Pitch = 1.27mm Pitch.

Can you measure the thread OD that white plastic part and tell us what that is?

As for the Fusion update messing up your custom thread file(s): I always recommend the excellent ThreadKeeper add-in. This takes care of copying all your custom thread files to the new location when Fusion updates.

Hope this helps, and don't forget to keep us updated.

---

[peter_e_stokes]

Hi Thanks again,

Most bank rods, landing nets etc here in UK will be the 3/8 thread, I bought two shorter bank rods a couple of weeks ago and they were 3/8.  there are attempts to bring in different sizes but the universality of the 3/8 size makes it an up hill struggle.

The thread on the white piece is 9.55mm OD

I will see if I can buy some of the M10 1.25 bolts

Thanks for the tip on threadkeeper, will definately look into that, hopefully it has a Mac version.

[MRWakefield]

No problem, you're welcome.

I'm in the UK too (Bedfordshire), I don't know why but I thought you might be in the UK as well. I'm still amazed that they're still using Whit form (BSW/BSF) so many years after we went metric. I've been in sub-contract machining for over 40 years and I don't think I have ever I been asked to work on Whit form threads (except for BSP and BSPT pipe threads). I obviously know what they are, and have had to use them when working with very old machinery. Anyway, onto trying to identify your thread...

Thanks for measuring that plastic part. It's measuring a bit above the maximum allowed for a 3/8" BSF (and also has a sharp crest and root) and quite a bit undersize for an M10. Commercial threaded components can often be a bit undersize (or a lot undersize if coming from certain countries to the east!), but very rarely oversize. It would be great if you could measure the pitch dia. (or as we used to call it: effective dia.) but that requires specialist equipment.

I've had a look at Screwfix and B&Q but they don't seem to stock M10x1.25 so I think the best place would be Ebay or Amazon, that's unless you have a good old-fashioned ironmonger's close by! If you think you might want to identify various threads in the future you might want to invest in a set of these:

They're usually Metric (coarse and fine series) and Unified (UNC & UNF). I'm not sure if you'll find one that covers BSW & BSF though.

I did check the ThreadKeeper page to make sure there's a Mac version so you should be able to use it.

Don't forget to let us know how you get on.

[peter_e_stokes]

Good evening!

Fancy you being in bedfordshire, you've probably heard my screams of frustration as I am in St Neots!!

Not had time to get stuck in till this evening and managed a couple of hours. So I got a normal bank stick with brass threaded piece and that measures 9.22mm a bit smaller than the white plastic rest which was 9.52mm.  So I tried to amend the threadfile for BSF 3/8 so major dia is 0.3622in (9.2mm in imperial (I hope)) but when I try to put a 3/8 thread  on a cylinder the drop down for size still only shows 0.375in.  I figured it out though, I needed to change the <Threadsize> field to get it to show correctly, though I guess setting major dia to 0.3622 would override the Threadsize field?

Is there a breakdown anywhere of what the fields in the threadate.xml files mean?

I'm hoping that printing at 9.2mm and not 9.52mm might accomodate some spread from the 3d print process.

Cheers, Peter.

[peter_e_stokes]

And just like that, the printed thread screws in nicely (I printed a small stub with thread and now printing finished rod rest) 

.

I learned so much doing this and as frustrating as it was, so happy to have finished it, even though I can buy a rod rest top for a couple of quid, as a vehicle for learning it was great.

Thanks for all your help, didnt expect you to be local, thought you were in the US somewhere!

Cheers, Peter.

[MRWakefield]

That's great! I've been putting together a reply to your previous post but I've been delayed with various things. Anyway, good to know you've had success and you've learned something along the way.

I'm in Leighton Buzzard so not too far away. I wondered where those screams were coming from!! 😂 If you need any more help just shout.

ATB, Marcus