+-

+-User

Welcome, Guest.
Please login or register.
 
 
 
Forgot your password?

Recent Posts

Re: Front Axles by RhysN
Today at 11:40:34 am

Re: Front Axles by RhysN
Today at 11:34:24 am

Front Axles by RhysN
Today at 09:57:55 am

Re: Electric motor systems by RhysN
Today at 05:48:24 am

Electric motor systems by StefanN
20 July 2019, 10:59:38 pm

Re: Steering geometry by RhysN
20 July 2019, 07:47:29 pm

Intro to Racecar Engineering by StefanN
19 July 2019, 04:38:34 pm

Re: Wolseley Hornet Cyclekart by GeoffM
19 July 2019, 03:52:27 pm

Re: Wolseley Hornet Cyclekart by StefanN
19 July 2019, 12:52:46 pm

Austin 7 info by StefanN
19 July 2019, 12:49:26 pm

Top Topics

Views Replies
Bugatti Type 37 Build 1134 73
New build start..GN Thunderbug. 395 42
Morgan F build 442 38
Austin Ulster build 872 36
Competition time! 554 34
CK 1 (ERA) build 396 31
Wheels 338 26
Stretton Karting Circuit (Leicester) Sunday 5th May 2019 276 20
Builders meet 31st March.... 300 20
Leaf springs eternal 330 19

Author Topic: Bugatti Type 37 Build  (Read 1134 times)

StefanN

  • Administrator
  • Full Member
  • *****
  • Posts: 173
  • Location: Bagshot, Surrey, United Kingdom
    • View Profile
Bugatti Type 37 Build
« on: 01 January 2019, 10:43:54 pm »
OK, so starting our first CK with my son. I've been interested for a while and then the GB meet at Stretton Circuit 2018 was the final push.

Our inspiration is coming from the Bugatti Type 37, a well trodden route for CK's and the quality of some of the cars I've seen is impressive if a little intimidating. We're lucky enough to live near the Brooklands Museum so have had a good close look at the T37 they have there.

« Last Edit: 01 January 2019, 10:53:46 pm by StefanN »

Share on Facebook Share on Twitter


StefanN

  • Administrator
  • Full Member
  • *****
  • Posts: 173
  • Location: Bagshot, Surrey, United Kingdom
    • View Profile
Bugatti Type 37 Build - mock-up and chassis build
« Reply #1 on: 09 January 2019, 12:14:50 pm »
Have taken the CK from a quick wood and cardboard mock-up that gave us confidence that our outline design will work, through to rolling on 4 wheels.

Rear hubs
We got a standard hub from Gemini Karts but with the studs pulled. The hub has 4 holes on a 100mm PCD.
To allow the hub to fit the wheel we cut about 5mm from the inside face of the hub. Four M8 bolts then hold the hub and wheel nicely.

We cut my 50mm length of Oilite bushing into 4 and pressed these into the wheels using a long bolt, large washers and tightening the nut.  We had to ease the inside of the bushes with some wet and dry to help them slide onto the axle. We assume they got a bit compressed when we pressed them into the wheel hubs.

Following advice, we chamfered the edge of the keyway on the axle where the bushes will be.  The wheel spins very smoothly on the axle with no slop - very pleased.  A split collect on the outside of the wheel keeps it in place with a circlip on the end for good measure.

The attached sketch shows the set-up.

Front axles
The front axle beam is from Gemini and has 16 deg camber and 5 deg caster.  Replaced the bearings on the front wheels with 35/17mm bearings.    Turned a stub axle and welded it to the Gemini yoke at 16 degrees (should have gone for 17 deg for the tiniest bit of positive camber).

The front springs are 35mm x 4mm x 560mm (and about 80mm drop from memory), made by Midland Motor Springs.  They're held onto the front axle beam with standard exhaust U-bolts through a bit of plate.


StefanN

  • Administrator
  • Full Member
  • *****
  • Posts: 173
  • Location: Bagshot, Surrey, United Kingdom
    • View Profile
Re: Bugatti Type 37 Build
« Reply #2 on: 13 January 2019, 10:09:54 am »
Built my rear engine mount inspired by Steve Cole’s design
« Last Edit: 13 January 2019, 10:11:53 am by StefanN »

RhysN

  • Sr. Member
  • ****
  • Posts: 253
  • Location: Tamworth
    • View Profile
Re: Bugatti Type 37 Build
« Reply #3 on: 13 January 2019, 10:11:42 am »
 :) Steve might tell where he got the concept from. Derek in Vancouver/Okanagan via me.
Stefan, with your rear hub mounting, if you dress off the small lip on the wheel you will get a better engineering solution as the hub will then bolt to a greater matching area.
« Last Edit: 13 January 2019, 10:37:25 am by RhysN »

StefanN

  • Administrator
  • Full Member
  • *****
  • Posts: 173
  • Location: Bagshot, Surrey, United Kingdom
    • View Profile
Re: Bugatti Type 37 Build
« Reply #4 on: 15 January 2019, 08:14:17 pm »
I welded the engine mount into position today and added a domed bolt to the side to act as a stopper and warning in case the axle or main drive gear/sprocket move towards the engine mount.

I picked up and old leather armchair from Freegle and stripped the leather from it. Should be enough to cover the seat
Winner Winner x 1 View List

RhysN

  • Sr. Member
  • ****
  • Posts: 253
  • Location: Tamworth
    • View Profile
Re: Bugatti Type 37 Build
« Reply #5 on: 15 January 2019, 09:04:55 pm »
That's a good idea Stefan, now for the other side?

StefanN

  • Administrator
  • Full Member
  • *****
  • Posts: 173
  • Location: Bagshot, Surrey, United Kingdom
    • View Profile
Re: Bugatti Type 37 Build
« Reply #6 on: 19 January 2019, 09:18:37 pm »
I had planned to copy Geoff and use a hand drill as a steering mechanism.  I ordered a drill on eBay but when it arrived realised that the pinions were aluminium and I thought they were unlikely to last long.  So I put a request out on Freegle and was offered a drill.  This turned out to be a lovely old Record drill - too good to cannibalise.  I got chatting with the guy who had offered me the drill and interestingly he is building a plane in his garage.   Anyway, I decided to try the angle grinder idea that Rhys mentioned and am pretty pleased with the result.

Also, roughed out the main formers and the floor so the CK's shape is starting to emerge.   A good day.


RhysN

  • Sr. Member
  • ****
  • Posts: 253
  • Location: Tamworth
    • View Profile
Re: Bugatti Type 37 Build
« Reply #7 on: 20 January 2019, 06:08:16 am »
That's looking really good Stefan.

ChrisS

  • Jr. Member
  • **
  • Posts: 54
  • Location: Crowborough, East Sussex
    • View Profile
Re: Bugatti Type 37 Build
« Reply #8 on: 20 January 2019, 07:55:05 am »
Love the angle grinder idea, what did you use a 4.5 or 9inch?

StefanN

  • Administrator
  • Full Member
  • *****
  • Posts: 173
  • Location: Bagshot, Surrey, United Kingdom
    • View Profile
Re: Bugatti Type 37 Build
« Reply #9 on: 20 January 2019, 08:45:43 am »
It’s from a 4.5” grinder that was “not working” (Freegle again).  Removing the armature was a bit of a pain but just took time with a hacksaw.  There was also quite a lot of backlash which turned out to be a loose key in the larger wheel.

There are so many premade mounting points and on this particular one the handles came out at 90 degrees so I’ve got two threaded M8 holes I will use to mount it with.

StefanN

  • Administrator
  • Full Member
  • *****
  • Posts: 173
  • Location: Bagshot, Surrey, United Kingdom
    • View Profile
Re: Bugatti Type 37 Build
« Reply #10 on: 20 January 2019, 09:50:14 pm »
The floor went in today and started on mounting the brake calliper, plus lots of little bits of fiddling.

StefanN

  • Administrator
  • Full Member
  • *****
  • Posts: 173
  • Location: Bagshot, Surrey, United Kingdom
    • View Profile
It’s taken a few iterations but both the front spring/axle set-up and the steering box are in place.

We added spring seats/perches that will help ensure the axle doesn’t rotate and hence keeps castor and steering geometries fixed.  We also changed the position so the spring is resting on the axle rather than hanging from the axle.

The angle grinder based steering box needed repositioning but is now in place and appears to be working well.  The second set of brackets in the photo above the steering are left over from the original position and I might remove them later.
« Last Edit: 04 February 2019, 09:41:46 am by StefanN »

StefanN

  • Administrator
  • Full Member
  • *****
  • Posts: 173
  • Location: Bagshot, Surrey, United Kingdom
    • View Profile
Re: Bugatti Type 37 Build
« Reply #12 on: 10 February 2019, 08:45:24 pm »
Well we thought we had got away with putting the brake calliper too near the engine, but it just wasn't right and was making adjusting the engine position difficult.  So we cut the mounting bracket off and will re-position it some time this week.  The good news was that the welds seemed pretty solid - so my welding must be OK!  Lots of other jobs going on like cutting chain to length, cutting and fitting keys in the axle, planning engine cut-off switches etc....but nothing photo worthy.   The next milestone we're aiming for is a drivable chassis.


StefanN

  • Administrator
  • Full Member
  • *****
  • Posts: 173
  • Location: Bagshot, Surrey, United Kingdom
    • View Profile
Re: Bugatti Type 37 Build
« Reply #13 on: 16 February 2019, 07:01:28 pm »
Took the governor off the engine today and started trying to figure out how to set up the throttle linkage  (all sketches/photos of other's set-ups welcome - I'll start a thread in the tech forum.)

RhysN

  • Sr. Member
  • ****
  • Posts: 253
  • Location: Tamworth
    • View Profile
Re: Bugatti Type 37 Build
« Reply #14 on: 16 February 2019, 07:33:21 pm »
My"10 minute to make, zero cost" version.
The pivot is a 4 mm ss bolt, with a corresponding "rivnut" in the fan housing, or before I had rivnuts I used nuts and bolts after taking off the fan housing and using a locknut inside (nyloc) and standard nut outside. Please remember I will always try to find the absolute cheap arse way out! It is a dead copy of NR racing item, just a whole lot cheaper.
« Last Edit: 16 February 2019, 07:38:01 pm by RhysN »