Showing posts with label bend. Show all posts
Showing posts with label bend. Show all posts

Saturday, October 30, 2010

Steering column mount

Also along with all the other parts that have been coming along in the last few weeks is the steering column mount.

This came in with a whole mix of parts we had on a laser cutting order that we waited 2 months for.

Once it finally came we got a small sigh of relief and everyone has enjoyed been able to sink their teeth into some good fabrication work.

This part was again designed with solidworks, based on dimensions from laster year car. This was a slight over-sight, there was last minute changed on the fly last year to ensure that the car would pass the technical inspection at the FSAE-A competition and one of the parts that changed was the steering column mount.

As with many of the changes the CAD model didn't really get around to being acurately updated and so the laser cut part came back over size. It was not Until Errol Hassett had bent the part up that he realise his slight mistake BUT we were able to over come this.

To fix it we simply milled a portion out of the centre of the bracket to shrink it inward but maintain it other geometry, this means it will pass the rules set by SAE for the technical insepection, Errol also thought ahead and has updated the CAD model to try and limit the possibility that this will happen again.

The probelm only set us back about 30 mins, live and learn.

Hold tight: Steering column mounting bracket, showing the fabricated and bent part vs the laser cut blank that we ordered. We often order 2 copies of parts that are bent up encase there are errors in our fabrication we have a backup.
You can see the slight differences between what it would have loked like and what it does look like after it's been bent up on the magna-bender and then milled and welded and grinded flush again. The milled section where there is a pocket for the steering column to run through the centre did have a nice semi circle end cut but for some reason the technician when he milled it change that to a squared off end with fillets, despite there being instrution to maintain the same single radius end on the modified finished part.

These things happen, the part is still within our "GOOD" good standards so it will be used. It is currently mocked up on the chassis and waiting to be welded this coming Monday.

We can up with a marking scheme for our work. We realise that nothing will ever be perfect or that it can take too much time to achieve this but we need things to be better than just satisfactory. So we invented the "GOOD" criteria, if it's not quite perfect but it is better than just satisfactory for the intended good then its good and can go on the car.

Cockpit liner mounting bracket

With laser cutters taking a long time just to get quotes back to us some of us have started to do things the old fashioned way.

Errol needed a bracket for the cockpit liner to mount to so this is how he has gone about producing it.

  1. Model it in solidworks
  2. Print it out on paper            (very high tech)
  3. Cut it to shape
  4. Glue it to appropriate sheet steel (a glue-stick can be a handy thing to have in the workshop at times)
  5. Gut to size with angle grinder   (used a cutting disc, worked a treated, rough shaped first then neaten)
  6. Clean edges with bench grinder and sand paper    (just to get rid of burrs and sharp bits)
  7. Centre punch marks for holes
  8. Drill holes     (all the holes were basically the same diameter, made life very easy)
  9. Bend edges with Magna-bender    (often can't bend certain edges because not enough materail exposed to the magnetic strip for a great enough force to resist the bending motion, will often just lift off the bed, can become a hge pain in the butt)
  10. Bend other edges in vice with hammer and large amount of skill slash luck
  11. Test fit in chassis
  12. Hammer the bends some more
  13. Test fit again
  14. Mark position for welding
That all may seem a little silly but it got the job done and we don't have to wait weeks for the part, all in all only took 3 hours from thought "....I should make that bracket " to " I just made that bracket " so that's not so bad.

Cut and paste: The paper template glued to the sheet steel for cutting, cut the shaped pretty close 1st go but not too close then I went back and tidied up the tricky bits and fish mouthing on the ends all with the cutting disc. About 15 - 20 mins work

Bending my way around a problem: The magna-bender wasn't being friendly so I resorted to alternate methods, not pretty way to do it I know but it got the job done in the end, only had to go back and forth twice after my initial gues at the bends. Surprisingly the end product fits almost as designed, definately close enough to be deemed in the " GOOD " range of work.

The part is now mocked up in the chassis ready to be welded in place on Monday, I will upload a picture later of the final product, I seemed to have forgotten to take a happy snap of it at the time.