graearea Posted January 6 Share Posted January 6 I've been thinking about this for a while. for the same cost of taking to to someone that knows what they're doing, I _think_ I can get 95% of what I need with home made and cobbled together stuff. to do the whole thing I'm gonna need: flat floor corner weight scales string alignment kit camber gauges ride height measurement 70kg of ballast so my current plan is 2mm plywood shims and a decorating laser level to get "flatness" £20? 300kg parcel scales with ramps 4x£38 +plywood for ramps magnetic digital angle gauge attached to brake disk through wheel for camber £12 castor, can't do much about I'm putting together a string alignment kit from cut-down 2m carbon fibre poles (40ish quid) 3d printed (suprise, suprise) parts to mount on the number plate (should be able to get it to the height of the middle of the wheels and sitting on my oil cooler). these will be able to measure toe-in although I suspect I need something to increase the distance of the front-and-back-of-wheel measurements from 13" to increase accuracy. £50 tape measure for ride height 20kg of water in a fuel jug and kettlebells. so total cost around 250ish quid problems ramps might need to be big enough to roll car on and off. I can make them just with layers of plywood or print some parts. parcel scales might just be a massive faff and not accurate enough. is string alignment accurate enough for getting toe accurately enough? I'd think yes, but all the toe dimensions I've seen are down to 0.03 deg, which is 0.2mm over 13" of my wheel.... I don't know where to measure ride height from. The other stuff I don't know that I don't know. I've ordered one of the scales https://www.ebay.co.uk/itm/354889360086 to test them before ordering 4 and I've made the pole hangers and little bobbins (getting the tension on these right was a nightmare) for the string kit and bought some nice yellow kevlar string. hopefully next week I can test the scales, see if they'll sit happily with 210kg of car sat on the rear wheels, cut down the poles to an appropriate length and then I'll order some plywood. any glaring problems? Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted January 6 Member Share Posted January 6 "DIY garage alignment": So not about feng shui or ley lines? ; - ) Jonathan 2 Link to comment Share on other sites More sharing options...
Colin_T Posted January 6 Share Posted January 6 (edited) Looked into using those very scales for a cheap DIY project too. I bought one , and I ended up using it as a parcel scale. lol. the problem I saw was the load cells are made up of having one in each leg, and they kind of cant and move about quite easily. I was concerned there would become issues with sidewards loading. I didn’t pursue it as already had set of scales at my workshop. You could maybe minimise the loading by incorporating some kind of moveable platform on top of the scales so that that moves rather than risking the legs moving about or breaking or giving inconsistent readings ??? ballast: I use a punch bag in the seat, plus various other items I had in the garage, a leisure battery in the footwell, a 10kg bar bell, and various half empty cans of oil and screen wash scattered about until I replicated exactly the figures with me sat in it. as for the on car rig for strings, if it’s likely something your going to be doing once in a blue moon could just do the old fashioned way with chalk lines, plumb bob, string and axle stands. find true centre of the front and rear of the chassis, drop plumb bob down, mark floor, run chalk line through front and rear marks to create your centreline. Then measure out from centreline equally and create two outer parallel lines either side of the car with the chalk line. then axle stands and string using the plumb bob so the string is exactly above the outer lines. Measure from lines to wheels. issue with this method is you can’t move the car, like jack it up to make changes because it will slightly move. however with some time spent you can realign the car onto your centreline marks and recheck with the plumb bob. cheap magnetic angle finder works well, can attach it to a simple rig, bit of angle iron cut to length so it sits on rim face. Just need a surface you can accurately zero it off of. decorators laser level works fine for levelling of pads too. also can use it to recreate “floor level” once the car is actually on the pads so your measuring back to a flat floor, just in case there’s any dips or bumps in the actual floor you are measuring to and trying to subtract the scales height (which may be all different too depending on your floor) measuring the the “laser floor” saves any of the maths ! ride height: for me it’s the lowest point of the sump “A” on the side of the bodywork as it goes from round to square section. and “B” just in front of where rear arch attaches. Simon Rogers of Meteor Motorsport gave me very helpful information with this with regard to a base set up, what kind of ride heights I’m looking for, rake angle, castor, camber etc. Edited January 6 by Colin_T Damn autocorrect 1 1 Link to comment Share on other sites More sharing options...
graearea Posted January 6 Author Share Posted January 6 thanks for all that Colin. good to hear I'm not a million miles off an idea 😄 1 Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted January 6 Share Posted January 6 To solve the lateral "stiction" problem I just use a flat piece of 0.5" thick plywood with 4x 1" wooden dowels underneath it. One side of the car has the scales resting on 1.5" thick wood pads, the other side with the scales on the 1.5" thick roller pads. Otherwise the setup envisioned sounds similar to what I have used for years, although I have 3x 23kg bags of "play sand" (designed for creating kiddie sand pits it seems) for ballast. 1 Link to comment Share on other sites More sharing options...
graearea Posted January 6 Author Share Posted January 6 I wonder if greased metal plates would work.. Well see Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted January 6 Share Posted January 6 47 minutes ago, graearea said: I wonder if greased metal plates would work.. Well see Oil would be better than grease, but a wet plastic bag is also good. the rollers though are easily the lowest friction method that is easy to achieve for the price of a bit of dowelling and plywood. Link to comment Share on other sites More sharing options...
Colin_T Posted January 6 Share Posted January 6 I remember seeing something like this re plate sat on rollers. Think it was in an old suspension book I read when I was about 15! 1 1 Link to comment Share on other sites More sharing options...
graearea Posted January 6 Author Share Posted January 6 the other thing is really I should have swivel plates. but I oily metal plates it is 😄 Link to comment Share on other sites More sharing options...
jbcollier Posted January 6 Share Posted January 6 Make sure you also get a gauge that can check caster and the included angle. Those are the best indicators for bent parts. Link to comment Share on other sites More sharing options...
graearea Posted January 6 Author Share Posted January 6 (edited) my 12quid angle gauge can't 😄 I just tried it. sticks to my cage and shows me that I have a 1/2 deg lean on my floor to the plywood store! Edited January 6 by graearea Link to comment Share on other sites More sharing options...
7 wonders of the world Posted January 7 Share Posted January 7 I use plastic bags cut on the side joints the older style crinkle ones work best Link to comment Share on other sites More sharing options...
7 wonders of the world Posted January 7 Share Posted January 7 Be care with the £30 ish digital scales as you can crack the plastic top plate as cambered rears concentrate the load in local areas. I have thick ply bonded to the top after I cracked one whilst checking 2 up and full tank weights... Obviously James and his 3x23kg bags won't have worry.... Can't remember when I was that light... Clearly I need to reduce my personal ballast... Though I do get great traction 1 Link to comment Share on other sites More sharing options...
graearea Posted January 8 Author Share Posted January 8 alignment poles are done. I think something to stop them from being knocked in the... tight space that I have to work with might help. maybe just something to ziptie it to the reverse lamp. scale seems quite stable and when powered from usb, doesn't turn off. now for some ramps. I'll need a bunch of 10mm ply I think for which I've just bought a jigsaw... spend 200quid to save a few quid. Link to comment Share on other sites More sharing options...
Graham Hutton Posted January 10 Share Posted January 10 This is really interesting. I fancy having a go myself in my garage so will keep reading with interest. My initial thought was to buy an industrial unit and equip it with a 2 post ramp, all the finest tools, some formula 1 spec scales and alignment measuring equipment, a couple of extra caterhams, a Ferrari dino and a Mk1 Mini Cooper......but then I woke up 🙂 It's amazing what a difference the flat floor setups I have had done make to the feel of the car and I would love to be able to tinker a bit more readily myself. Keep on keeping on guys, I might hang onto your coat tails 🙂 2 Link to comment Share on other sites More sharing options...
graearea Posted January 10 Author Share Posted January 10 tested the first set of scales last night and had a problem where they'd turn off after 30 seconds. turns out they were pulling so few amps from my battery pack the battery turned off 😰 they happily sat at 200kg with one wheel propped up and the other sat on the scale. 3 more scales ordered, total cost about 140quid. jigsaw should arrive tomorrow so I can go buy some wood, strap it to the rollcage and bring it home, then start chopping up wood for ramps onto the scales. I'll keep you posted. Link to comment Share on other sites More sharing options...
Gridgway Posted January 10 Share Posted January 10 It's not the direction you are going in, but I have a set of corner scales that I'd be happy to loan... 1 Link to comment Share on other sites More sharing options...
graearea Posted January 10 Author Share Posted January 10 Where abouts are you? it'd be interesting to compare the two solutions. (as much as my hack is a solution 😁) jigsaw arrived and it's a nice bit of kit. off to Jewsons tomorrow and strapping some 2.4x1.2m plywood to the roof of the 7! Link to comment Share on other sites More sharing options...
jody391 Posted January 11 Share Posted January 11 I made myself a set of 40mm thick aluminum plates with a threaded bolt in each corner so I could adjust the plate heights to match the garage floor imperfections. Once they were set up the bolts then stay in place and all I have to do is put them in the correct position on the garage floor (marked out) and in the correct orientation, and I have a flat floor, or at least way better than before! I then bought some aluminum tube and machined a joining boss so they could be longer (2m) and then machined grooves at the same positions on all ends. I use axle stands all four are identical to hold the tubes, it takes a little time to align the square but easy enough to do. Its way more difficult on the Elise as the body work and diffuser gets in your way when adjusting! I then made my own alignment rack to hang off the body work but ended up still using the string poles and axle stands as it was a faff! 1 Link to comment Share on other sites More sharing options...
Gridgway Posted January 11 Share Posted January 11 14 hours ago, graearea said: Where abouts are you? it'd be interesting to compare the two solutions. (as much as my hack is a solution 😁) jigsaw arrived and it's a nice bit of kit. off to Jewsons tomorrow and strapping some 2.4x1.2m plywood to the roof of the 7! I'm in Epsom Link to comment Share on other sites More sharing options...
graearea Posted January 11 Author Share Posted January 11 Oh that's actually doable. I'm in Camden. it might actually be easier some time for me to just bring my scales to you and do a comparison Link to comment Share on other sites More sharing options...
graearea Posted January 11 Author Share Posted January 11 First go with the scales. the floor just isn't smooth or flat enough. I need to go buy some thick plywood. lifting and dropping the wheels got slightly different weights by ¬200g off to jewsons tomorrow perhaps! Link to comment Share on other sites More sharing options...
graearea Posted January 16 Author Share Posted January 16 current progress: got some 9mm plywood down on the floor to level and create a better surface for the scales.I need to buy some 3mm mdf sheets to fine tune it measured with a laser level and the floor is about 20mm lower at the back, this can be fixed with some chopped up ply and a tape measure. the scales definitely give slightly different results depending on where the wheel sites. I'll have to mark the scales so that they're central. the scales all measure 70kg within a few 100 grams. I need to try this whilst holding another 50kg. I remembered that I own trakrite alignment kit that I'd never used because the floor in my garage was too uneven. will see what it's like now. the 10quid magnet angle gauge works brilliantly. Link to comment Share on other sites More sharing options...
graearea Posted February 2 Author Share Posted February 2 Who knows how accurate it all is. This is my starting point Link to comment Share on other sites More sharing options...
Gridgway Posted February 2 Share Posted February 2 Looks impressive. Is that with a driver weight in or not? Link to comment Share on other sites More sharing options...
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