Posts
581
Joined
2/10/2014
Location
GB
Edited Date/Time
9/4/2018 8:07am
Ok guys, here is a sneaky pic of what I (well I say "I", but really my best friend Stacey was doing the CAD work, I was making coffee and giving the design input) working on all day on sunday.
It's NOT finished but it should give you guys an idea of where we're heading.
The rear axle blocks and shock mounts (and on the right hand side the chain guide mounts) along with the front bearing sections will be CNC machined from single pieces of alloy. So there will be zero chance of them being in the wrong place!! All the sheet alloy is modeled as well, so they will be CNC lazer cut and bent. They will be identical every single time.
Hopeing to get to a price of around £650-750.
Stevie
It's NOT finished but it should give you guys an idea of where we're heading.
The rear axle blocks and shock mounts (and on the right hand side the chain guide mounts) along with the front bearing sections will be CNC machined from single pieces of alloy. So there will be zero chance of them being in the wrong place!! All the sheet alloy is modeled as well, so they will be CNC lazer cut and bent. They will be identical every single time.
Hopeing to get to a price of around £650-750.
Stevie
Love your optimism.
It more based on my experience of CNC guys telling me it cant be wrong because its done on a CNC.... I am currently doing a post mortem on some parts to try and establish the cause of death. My man assures me that it cant be wrong, despite my $200K machine saying otherwise, and my $60 caliper saying the same.
I am happy to run my professional eye over it, If it has CAD , I can inspect the arse out of it.
The Shop
You would be amazed how far out stock stuff is, we used to shorten swingarms, our guy had a big jig, so they didn't distort when cooling, and he used is to hold the arm to cut it too.. we took 4 and 3 of them didn't fit the jig .
I'm really looking forward to your 1973 - 1974 Honda CR250M swingarm that, I hope, is still forthcoming.
Thanks for the great parts!
If you're going for a work of art then what you have modeled is going to look awesome. If you want to reduce manufacturing costs and time I'd make it out of three machined parts that are connected by off the shelf rectangular tuning. You could take a lot of stress off the welds if you machined tabs that insert info the box connecting sections.
When we design lift fixtures we always insert the lift lug into the beam so that the weld just holds it in place rather than be in shear.
Good stuff as always Stevie!
Once this CAD model is finished, changes can be made relatively simply, so other arms can become a possibility.
Stevie
The arms will be made from 6082 Alloy (which is the UK/ Euro equivalent of 6061) and they will be T6 heat treated. The company that does our heat treatment does the all the heat treatment for Orange MTB's and when CCM had a GP a few years ago (when they used Yamaha YZF engines) they did all there frames and swingarms. So they know there stuff.
Stevie
Or they will be too heavy
or How many parts to a arm?
pivot section?- solid ?
Why not mill out some die's and press out
the shapes like the factory bikes, and
make a kick ass fixture for welding
nothing will move
you will have to have one anyway!
We don't have access to press tooling so that method is not an option. We are making the welding jigs and fixtures as well.
At the moment, according to Solidworks, (the CAD package we're using) it's already over a 1kg lighter than the stock arm and we haven't even started on the weight reduction. I think there's at least another 1.5kg maybe 2kg to come out of it.
As I said, this is the first 'basic' model, there are lots more refinement to do.
I should have mentioned in my OP they will be 1" longer than a stock 1980 arm (so 2" longer than a 78-79 arm) to improve the handling.
Stevie
Stevie I'm sure it will turn out like all the other projects you tackle and be awesome.
Looking forward to seeing the final product.
The question I would have for using your swingarm on a 78-79 is, the brake rod will be too short with the extra 2 inches, and with a brake arm that will work on a 78-79 and extends long enough for a 1980 will be too short as well.
PK
It's taking WAY longer than I wanted but they are still on the go. I sent out the CAD programs in December for quotes (they are little beyond our current machining capabilities) to one of the companies we have worked with for years... not heard anything back yet after numerous calla and emails.... so stuff em! I've sent the CAD programs out to around 12 other companies for quote last week, should hear something back next week.
I'm desperate to actually get them started!! We've out so much work in, I just want them done and ready to go!!
Stevie
Pit Row
So, my plan is to offer the option of a complete "kit". Swingarm, bearing set, chain slipper (I'm going to have them molded to fit the arm properly!), roller lowering kit, brake trq arm, rear chain guide, lower shock bolts, rear wheel spindle and spacer set. I might even do some with Titanium RC style rear axles!!
Here's the finished CAD model, just so you know we have been working on em.
Stevie
I hate to beat a dead horse, but I was wondering if I could get an update on the swingarm kits. Do you think the arms will be available by next spring (April or May, 2019). Don’t want to be a pain, but just trying determine how I can give PDE more of my money. Now get back to my kickstarter?
Post a reply to: 1978-1980 CR250 alloy swingarm. 1st CAD model.