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So the bike was then put back together with all the fasteners thread locked.
I decided to be decedent and bought a front brake adapter rendering the 5min fix redundant.
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The bike all back together, before i ruin it with mud guards.
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So a test ride was done yesterday around Sherwood pines. A few runs down the "down hill" runs and no creaks or crack and some climbing where possible.
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Over all am pleased the bike holds up well i just need to get fit enough to pedal it and used to riding a full suss after nearly 2 years of rigid. Had some nice comments from a few people i met on the down hill run which was nice.
In three hours of mincing these are the only bolts to have moved.
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I think the biggest compliment about the bike is it takes people awhile to realise it's home made.
Very nice, top stuff. Love the idea of a MF seat clamp.
Inspirational stuff! It's got thinking about if I could do something similar.
Although I don't have a 3D printer. Maybe build the front triangle out of stock tubes... 😉
Some testing miles done now.
Geometry is spot on for me, looks a bit strange when un-sagged but managed most of the climbs on a peak route (fitness allowing).
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A few problems flex on the swing arm to front triangle is bad when climbing rocky stuff, not unnerving just flexy. This has led to a bit of chain ring to chain stay interference. I think some of it is due to the design of the swing arm and some to the polymer bearings which have to be a super tight fit and still give some radial give.
So a plan for mk2 is being hatched to solve some of the issues.
Maybe build the front triangle out of stock tubes...
This was the original idea, i just got carried away working out ways to make the rear end, (which is the hard bit).
Maybe build the front triangle out of stock tubes...This was the original idea, i just got carried away working out ways to make the rear end, (which is the hard bit).
For my first go, I'll probably re-use a rear swing arm from something or other. I have the front triangle modelled in CAD, I would have to place the pivot points to replicate (as best I can using linkage X3) the bike the swing arm came from.
The bike looks good, glad you're getting hours in saddle testing. I'm sure you'll sort out the rear end flex.
Not if I can post this here, but[url=
The pivot bearings seem to be more substantial than yours, maybe you should start there!
This is incredible!
Do you have a background in engineering?
possibly my most favorite thread this year!
Where has the time gone?
A plan was hatched for a mk2 swingarm using some inspiration (stealing the ideas) from specalized to fit bearing in the links, that way I wouldn't need to re make the frame.
Printed out with very little infill and is over 100g lighter than the old one.
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And then work/ life actually riding a bike got in the way again. last week i had a crazy stressful week at work so to wind down had a weekend on CAD, which turned into looking at the frame design and seeing if it could be made lighter. I got carried away.
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Completed abandoned any internal support and my four layer thick test sample is quite stiff so in a tube should be good enough. Am after 1kg off the frame. This might be a slow burner though.
Do you have a background in engineering?
I was an apprentice tool maker and CNC machinist. Now teach engineering at a college, I use the lower links for a lesson on CAD use for a virtual stress test which always goes well. Have basically taught myself Solidworks though over the years.
[Rant] If I was a purveyor of certain bike products I could plaster this all over Facebook saying how awesome I was...[/Rant]
My goodiness! Just seen this thread now. Absolutely amazing. Might have to fire up my printer and buy some carbon...
Looks great! With the background info above, and the bike, you don't happen to be the Dean who worked at West Notts college in 2005-6?
Bit of play time on the 3d printer, now I've tidied the garage enough to get to it.
Stupid mistake on the print settings for support material meant a 16hr print!
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Comes in at 68g
Awesome thread! Keep it going.
This is great.
I have musings of an open source bike frame project, looking at standard frame rather than sus at first.
I would take a design from bike cad then have program output skeleton lugs.
You can then assemble with off the shelf carbon tubes, and wrap the joints.
Would just need head tube, dropout and BB shell inserts (could be cut from a scrap frame?) and a jig.
So here we go again!
Decided to put the bike back together and just ride the thing, so after building it up, changing the air shaft in the forks and packing the spare frame away i found this.
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Bugger- A crack from the chain stay de laminating across the pivot, well I'll have to do the other swing arm now.
So a weekend CADing between Dad duties and got the bike assembled to check clearances (already had most of the separate parts modelled).
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This let me then sort the jig out and work out what needed to be changed, to make life easy on myself i seem to have widened the rear pivot and narrowed where it meets the rocker so some of the jig parts at the minute are useless.
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So in between doing all this notice part of the swingarm was a bit close where it meets the pivot.
So quickly modified the model, chucked it in slic3r
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and bunged it on the printer for about 5hrs!
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Plus managed to glue the other parts of the swing arm together.
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Along with changing some dimensions I'm going a different route with the bearings. It's all been designed with asymmetric bottom bracket area (not current set up) so once again printed off some parts to check.
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Nope needs more [s]cowbell[/s] clearance
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That's better, just a dimension change and 20min print.
I've also managed to make some new jig parts and tools I'll get some pics and upload later on.
Still loving this.
More please.
Very impressed with this.
I'm an IT & Computing teacher, at my old school I used to run a 3D printing club, they would have loved reading this!
Great thread 🙂
Great thread. Keep up the good work.
So impressed, my mrs has a degree in Engineering Design and Technology and CAD was what she loved, she even did a little bit of CAD work on designing a Unicycle so she's blown away by it too.
Fantastic stuff 🙂
Loving this... I see you've deviated from the One True Glue Stick, purple elmers glue, do you find it makes a difference?
Thankyou all for the kind comments, glad someone finds my rambling interesting.
Loving this... I see you've deviated from the One True Glue Stick, purple elmers glue, do you find it makes a difference?
I used to use a glass sheet/ mirror but bought a new aluminium backed heat bed. I find the blue tape just works better. But i've spent along time leveling the bed and setting the extruder height to get the first layer right.
Yeah, I spent ages mucking about til I realised all I really needed was the right temperature on the bed and the height and settings just right. I mostly use purple glue straight on the bed but every so often, some bloody print won't come off the bed and needs soaked off 😆
Amazing and inspirational. 🙂
Right pictures of shaped metal as promised.
As mentioned I've widened the rear pivot by 10mm so made a spacer.
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Here's the mandrel as normal.
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And here it is with the spacer.
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Now epoxy is sticky stuff so to expect the spacer to come out easily is foolish, what you need is a tool to push/ pull the spacer out without twisting out of round or damaging the spacer. so 10min on a lathe you end up with..
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It doesn't touch any of the mating surfaces and is threaded so in theory I can pull it out using an existing washer, the main diameter is 0.1mm small so should stay concentric'ish.
Also rattled up a spacer for an existing jig part and a new part to hold the rocker connectors in the correct place.
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That'll do for today, looks a lot but didn't take that long to do.
Your garage must be man cave heaven bigdean.
Another update
The new swingarm was glued together ready for the first layer of carbon just to hold everything in place. The a mishap i kind of left it near a heater turned up to high and it warped.
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So this stupidly gave me time to adjust the design slightly, which obviously took way too long involving the front triangle, we'll get to that later.
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So again print out bits, this time though had a little experiment with hollow parts and some with infill.
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The hollow part is only a few grams lighter but way too flexible to be of any use.
A spot the difference showing some modifications made.
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I've also printed a new top tube as a test (which probably means i'm doing another front triangle).
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So under 100grams for the core will be good to monitor how much weight is added as we go.
Also been playing with the camera. here's a vid of the swing arm fitting together.
Fantastic ! How many £1,000's have you spent so far though ? 😆
You can't put a price on a hobby!
Fantastic ! How many £1,000's have you spent so far though ?
Not in the £1000's but if you dont count you can't say 😉
Good thread.
Any of you carbon fibre fabbers want to make me something really simple? Possible product to be made?
Ok bit of a while since an update, fortunately summer has been both good and bad for progress. Hols with family get in the way but got some time on the machines.
Managed to make the linkages and new bearing axels spacer and bolts.
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School boy error with the bolts though as both were aluminium. bare aluminium to aluminium = cold welded (bugger!)
So i found some Titanium bar ends I've had for ages and had a good day remembering to machine something interesting.
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Managed to get fusion to produce a usable program, plus have made some progress on the swing arm, have been trying to film some of the process so no pics at the min.
Swadding excellent dude.
*Shares with engineering/MTB buds*
What a great thread!
Looking forward to seeing the next instalment.
So under 100grams for the core will be good to monitor how much weight is added as we go.
Out of interest, why not print in PVA then soak it out of the frame afterwards?
Great project! Nice to see you getting stuck into this.
How many miles did you cover on Mk1 before it cracked?
Out of interest, why not print in PVA then soak it out of the frame afterwards?
Never knew that was possible. Very cool idea.
It's the clever way of printing overhangs without having to sand off the supourt afterwards, you print in two materials with PVA being used to print the support.Never knew that was possible. Very cool idea.
Only problem is, you've then got to design your parts with no overhangs, and build some sort of pumped warm water bath as it usually takes a good few hours to dissolve that much solid PVA.
I had never seen this thread before, but now I have, got to give a huge thumbs up. Can't wait for the next instalment!
Out of interest, why not print in PVA then soak it out of the frame afterwards?
How many miles did you cover on Mk1 before it cracked?Don't have a dual head printer, bought a cheap kit some years ago and built a new frame for it. dual extruder is a planned improvment but that will have to wait.
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**Note string and cable ties! missing duct tape though.
Not that many but i cracked it hanging up on some dirt jumps deliberatley abusing it. It road around the peak district fine (up hope brink, potato alley and over to fairhomes)