just started a new project,one i have had lurking about in my head now for a long time its going to be a fully floating all alloy atlas.Was only at this a couple of days and i,ve come down the a right dose of the man flu so only have a few pics but as soon as im up and about again i,l be full on at it.IMG00374.jpgIMG00374.jpgIMG00379.jpgIMG00378.jpgIMG00376.jpgthe tube itself started out as a 4inch solid billet of 6082t6 alloy,and the stub axles are made from en24t steel,
interesting to see how this pans out.
EVERY DAY,S A LEARNING DAY
Forgive my complete lack of knowledge here.
As I have no idea about the tensile strength of the aluminium you're using, or tensile strength in general.
But am I right in thinking that an aley bars rollcages use to fracture.
I realise this is completely different but is it not going to be slightly prone to this possibility under stress.
Or am I just barking up the wrong tree anyway?
Other than that it does look very nice.
thanks fridgeman i have put some serious thought and research into this project and im totally confident it will be as strong as a regular heavy wall axle but at least 10 to 12kg lighter overall plus it has in my opinion a bit of bling and also gives me a buzz making it,thanks mick
roll cage material is extruded alu and not very heavy wall this alu is in t6 temper and is machined from billet with 12.7mm thick walls .
Thats a decent weight saving. Will you use alloy for the brackets etc ?
looks great.
I love any bling like this
thanks wildo all brackets will be alloy with steel inserts to take the link bolts
Did n't Fossie build an alloy Atlas axle that had a Magnesium Pigs head for his light weight Escort that he built. I am sure there's a thread of it somewhere on this Forum. Look forward to more news on your axle mick.
Interesting one!
6082T6 ally has a yield strength of about 250mpa if i remember rightly, which is pretty good and comparible with mild steel. However most HD axle tubes I did were S355, which has a yield of 355mpa, and 8mm wall thickness. Forget about Ultimate tensile strength, the tube has failed well before you get there.
So with some simple calcs you can arrive at a tube OD and wall thickness that will give you comparible 'strength' to a standard issue thick tube Atlas...
However! Several things worry me about the ally tubes. What about strength in the heat affected zone? (Assuming you are welding brackets?) The welding will ruin the temper and strength will be 50-60% less than it was in T6 temper. That precise bit of tube, i.e. the bit that is now very weak, is also the most highly stressed bit of the tube... Then you have fracture toughness to consider - what will happen if the tube takes a hit? All axles do. Even the HD steel tubes come back bent after a few years of normal use so you can be certain they are being stressed to the limit. Then fatigue - aluminium does not have a fatigue limit so your tube WILL fatigue sooner or later, and the material in the weld zone will be particularly prone to cracking, unless the whole thing is post weld heat treated and the welding is very fussy. You will need some very thorough NDT (crack testing) initially and for the life of the casing.
I'm not saying it can't be done, but there needs to be some very serious engineering and metalurgical input or you risk, literally, a wheel coming off.
As it happens, i made on once, same idea as above (wasn't 6082 though it was something stronger) and was heat treated after welding. I chickened out of using it though, not worth the risk commercially. Different matter if it's for personal use though.
I concluded (and still believe) that high strength steel is a better material for the tubes - with some clever work you can have tubes at around 3 times the yield strengths quoted above, and tough enough that fatigue is not a concern. At that strength, you can get away with wall thickness that will end up way lighter than you'll ever get with aluminium.
Having said all that, have a look at some of the American drag and oval racers - they use ally tubes with clamp on brackets (no welding needed) which could make all the difference...
Great project though, keep us updated!
thanks for the input fossie i have weighed up all the above options,i will be heat treating the tubes again after welding i have my own heat treat oven that will only just take the tubes. this is by no means a commercial venture i have my own engineering shop with all manual machines and if anyone knows it isnt a matter of pressing a button and hey presto its done,no it takes hours and hours and no one sane would pay for that.as i said in an earlier post this has been banding about in my head for years now i have a bit of down time i,l get it done.should be back in the workshop tomorrow feeling strong enough again to get back at it,
got back in the shop today didnt get very good pics but i,l put them up anyway,first ones are of the Lh stub being machined and the others are of the first op on the l/h tube.IMG00384.jpgIMG00385.jpgIMG00386.jpgIMG00387.jpgIMG00388.jpgIMG00389.jpgIMG00391.jpglast pic is of a quick change toolpost i made myself earlier this year im quite proud of it.IMG00398.jpgIMG00399.jpgIMG00400.jpgIMG00401.jpgIMG00402.jpgIMG00403.jpgIMG00404.jpgIMG00408.jpgthese pics as i said are,t great but i got a bit more along with the project today.
got back into the workshop last night and early this morning and finished the left hand stub axle and finished the turning on the left hand tube if i get time tonight i hope to set up the parts in the milling machine and drill out the bolt pattern.IMG00410.jpgIMG00411.jpgIMG00412.jpgIMG00412.jpgIMG00413.jpgIMG00414.jpgIMG00415.jpgIMG00416.jpgIMG00416.jpgIMG00417.jpgIMG00418.jpgIMG00424.jpg
finished the left hand tube and stub axle it involved drilling counter boring and taping the holes ,first job was to center the part to the mill spindle and then machine the 8 bolt pcd.IMG00425.jpgIMG00426.jpgIMG00429.jpgIMG00430.jpgIMG00432.jpgIMG00433.jpgIMG00434.jpgIMG00435.jpgIMG00438.jpgIMG00439.jpgIMG00440.jpgIMG00441.jpgIMG00442.jpgIMG00443.jpgIMG00445.jpg
Lovely bit of mill/lathe work��
i haven,t had an update on this in a couple of weeks,had the flu over the christmas went back to work a bit too soon and had a relapse with a bad lung infection which i ended up in hospital with,now i,m back home so hopefully over the next few days i will get a few more bits done.
Fantastic work...love quality and the idea...keep the pics comming....cheers mark
Looking good matey.... that flu has been a right fooker this year
A small update had a real bad start to the year with health problems got a bad flu around christmas and that developed into a serious lung infection,anyway it set me back with a big backlog of work to catch up on so this put the axle on hold.That is until last week i took on board what people were advising about welding impact on the alloy so i had a good hard think and redesigned the whole set up as i wright this now i have a completed casing on my workshop floor and im very happy with its outcome,i will try my best to get photos up later tonight or in the morning.
Hope your better now...looking forward to an update...cheers mark..Originally Posted by mick32
some pics a bit later than promised.IMG00462.jpgIMG00463.jpgIMG00470.jpgIMG00472.jpgIMG00480.jpgIMG00481.jpgIMG00482.jpgIMG00484.jpg
this lot of photos brings us up to the present the 4 link brackets were a total pain in the arse to make but the end result is quite good.
IMG00515.jpgIMG00516.jpgIMG00517.jpgIMG00518.jpgIMG00520.jpgIMG00523.jpg
Is the bracket sandwiched between the tubes or does it clamp round.
Looks great though, keep it coming
its both sandwiched and clamped,it was a right pig to machine considering the bracket had to be timed with the bolt pattern and rod holes timed for axle location.it might look a straight forward part but it stretched my abilities .
sorry wildo just read your question again,the tubes a one piece items with 2 flanges machined on to it and a bolt pattern drilled . the 4 link brackets are 2 piece ie top and bottom placed between the flanges and clamped to the tube then there are six bolts go thru the flanges and 4 link brackets.hope this makes sense.
That looks brilliant
Not that I know bugger about tensile strength issues but it looks like it should be strong enough to me..
What sort of thickness are the 4 link brackets?
Last edited by rallyrob; 30-03-2018 at 04:17.
hi rob the brackets slot for the rod is based on mk1 escort 4 link bracket .9375in where as the overall thickness is 1.625in.there was a lot of head scratching with regard dimensions for bracket location on the tubes because it had to be spot on from conception,not like welding a bracket on to a tube where you can fine tune location after tubes are installed.
thanks for the explanation. Apologies for some reason i didn't the previous pics. All perfectly clear now it no wonder that tested you
cant blame pics are shocking quality just cant seem to let my old phone go its like a comfy pair of old jeans you cant bring yourself to throw out.
Got alot done to the axle this week drilled out the hubs with extra holes a was very surprised with the weight saving it was 1.3lbs per hub.I also made up the caliper brks and mounted the discs and calipers.Did a little test this eve and weighed a fully floating steel axle with hubs calipers and discs and it came in at 111.6lbs and then weighed the alloy one with hubs discs and calipers and it came in at 86.2lbs thats 25.4lbs weight saving.
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Lovely job Mick , this was the Zakspeed version they gave it up because it wasn't strong enough .
thanks duel i think this axle will be plenty strong enough for me its going into my mk1 road car with a 230bhp c20xe and not a fire spitting turbocharged bda pushing out over 400bhp.
Nice work mate
thank you rich
Why not stress relieve, ie pre-heat before welding? Surely if the weld is to a good standard you would only stress the areas through expansion and contraction of the weld filler material, controlling the temp by pre-heating would be the way ???
i agree to a point yes it would have been way easier to weld but to do so under very controlled conditions in my shop is not repeatable and the original spec of the metal temper even with a pre-heat would be altered,and therefore the whole setup would have to be re-heatreated .my heat treat oven dose not have the capacity for a part of this size and to be perfectly honest my heat treat knowlage only stretches to ferrous metals.so i think for me what i have made is the best solution for me and my abilities.thanks mick
Looking good Mick , I have been chasing a mag one that was a special one off build so will add the pic on the next post. Duel did Zakspeed just go back to steel then ?
img]http://media2.turbosport.co.uk/2013/11/2018092720104139245mag axle.jpg[/img]
Hope this works
You're missing a bit of the link code at teh start.
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