tonystott

The most innovative device I ever saw for damper units was the "top hat" used by Tamiya. This can compress to allow for the volume of the shaft as the damper is compressed, yet expand back on extension so there is no need for any air space. Clever thinking. I wish you could get these for bigger dampers

Frederik_b

Thinking about it I think I''ve seen something like this somewhere but dont remember if it was on an rc. It was a kind of closed cell foam acting like a baloon. I think its what is in the reservoir when there is an external reservoir.

Thanks for the ideas guys!

Fred

Lars from Norway

I have just started to overhaul some aluminium shocks for my FG now,they have some bladders on the top,i guess this is for compensating for the volume while being compressed.[link=http://www.fg-modellsport-gmbh.de/_PDF-ANLEITUNGEN/E.06000-01.pdf]Here[/link] is a link to a PDF on FG's site,part # 7088 is the bladder

Frederik_b

Yeah the bladder was also on the smaller shocks I had on my previous RC cars.What is wierd is there is nothing whatsoever on the cheaper red FG shocks I have here. The top cap is simply a plastic cap, no room for air.

Today I bought some tools for the lathe, that will hopefully help machining the shocks. And I read for a while today on the web about threading on the lathe, sounds not too complicated and will give it a try.

Here are the parts I bought:

Boring tool with holder:


left, right, and straight 1/4 inch tool holder:


1/4 inch tools:


small cutting tool:


Various boring tools that will fit the boring tool holder:



So next step is replacing oil in my lathe gearbox (cant seem to find 20W machine oil around here) and then I will try some threads on it.

Fred

Dirty_Vinylpusher

Actually I find those little tools pretty amusing, and not boring at all.
















Yeah yeah I know

Frederik_b

Hahah you actually made me laugh with that, kinda like the struts and ostrich I guess

Dirty_Vinylpusher

The tools in that picture reminded me of these little fellas.

Lars from Norway

HAHA!

Frederik_b

Nah DV actually I was unsure which tools to buy, you are probably talking about those:









































lol ok now seriously I bought additional tools yesterday, 2 high speed steel outside threading tools (60 degrees 1/4 inch) and also 2 1/4 parting tool. (yes DV, parting, not partying )

Did some testing on the lathe yesterday and noticed the gears configuration affect the threading adjustments and right now theire adjusted for extremely small threads so I'll have to play with the gears to get the threads I need.

Fred

Dirty_Vinylpusher

Hehe nice work.

Frederik_b

I machined the first of 4 diff holders. I will drill 4 holes to attach it to the vertical plates that will hold the diff. Imachined it out of 1.5 inch square stock. Now I just have to make 3 more

Ithink I will mount them from the outside, like in pictures 5 and 6(and like in the previous drawings)not like the last 2 pictures.














Fred

Lars from Norway

Nice nice!! Good to see some progress here again.

Dirty_Vinylpusher

Mmm nice shiny bits!

sam123

My Feedback: (1)

Very nice!

Im just wondering, how hard is it to keep square stock centered in the chuck? Did you use a 4-jaw chuck or is there another way of holding it that I'm not sure about?

Lars from Norway

You can put the part inside a pipe which have the same diameter as the longest distance on the square (diagonal?) so that the pipe clutches the square when you tight up the chuck. You have to cut the pipe longitudinally to make it move the few millimeters -or micrometers- to clutch the square of course.

Frederik_b

When I bought the lathe, there was a 4 jaw chuck included so I did'nt have to use Lars's trick with the tube, but it looks like it would work nicely.

So basically I used a dial indicator to help center the square stock on the 4 jaw chuck (the 4 jaw chucks are not self centering, each jaw is individually ajdusted).

Once I centered the square stock in the lathe, I started a small hole with a center drill at the right end of the aluminium square and put a dead center to hold it while I was machining it. I made the right end round on approx. 0.75 inch lenght so I could then flip it and hold it in a standard self centering 3 jaw chuck. I will keep this end machined round so it will be easier each time I will have to machine something out of this piece of 1/5x1/5 stock.

With the lenght of stock I had (about 6 inches) I am pretty sure I could not machine it without the dead center holding the piece on the right side.



I am not very experienced in machining, I'd have a question for the more experiencedabout tools. I tried to machine outside threads on an aluminium tube with a 60 degrees high speed steel tool but it did'nt give a nice smoothfinish. With my carbide tools it's much better but the end of the bit is sligthly round so it does not looks like it is made for threading, right ?



Is there carbide bits made for theading that I could screw on those tools?Those cut so much smoother.. Maybe it is because I grind the HSS bits with a bench grinder? Ihave seen threading carbide tools on ebay but I think they arelarger than what I need for my 1/4 inch shank tools, I don't know what to look for in size or part number.


Fred

Frederik_b

Wow almost 3 years without updating the thread... Time flies !

Frederik_b

So I guess it's time for the 2-3 years update! lol I have not worked on that one since the last post, had our second little baby boy recently and hobby time is limited lol. But the project is still alive, just kind of in hibernation

Recently I have been working on another custom RC in smaller scale ( and 1:10 Ford Escort MK2), which also uses macpherson front suspension, so I was able to experiment and test designs, it will help me come up with a better setup on this large one. Here is what I made in 1:10:






Among the things I learnt with this smaller build, the geometry is much better with the strut at an angle, and having the strut aligned with the bottom ball joint, as to reduce stress on the strut. I might have to modify the MCD wheels to make them narrower, both to have a more scale look and at the same time have more room for the struts, and not have huge offset (high offset will cause more stress on the strut..)


The Mk2 Escort thread in case you are interested, still working on it:

http://www.rcuniverse.com/forum/rc-e...scort-mk2.html

C.lyra

Hey fred, Nice to hear that your project still is alive... Have seen your escort project on another forum, and i must say.. Very very cool build..����

Frederik_b

Thanks buddy!! What about yours, the Impreza, have you done more work on it recently?

C.lyra

It is still alive too, i started again to design the chassis/suspension in inventor.. The Body mould is allmost done and made i vaccumtable with a steel frame to hold the lexan sheet, so i have all the parts, i just need the time to get it done...��

FirstGenLegacy

Beautiful post!
I'm in-love!!!
Being a Subaru fan myself, I support your build 100%, as for the more recent posts with the new shell, what happened to the last blue Sti shell?
Keep me updated!

Frederik_b

Thanks buddy! I am sorry I was being off topic with the last post because this is another project I am currently working on, an 1:10 RWD solid axle Fort Escort MK2. So the good news is the STI shell is still being used for the large scale project this thread is about, the less good news is the project is still on the back burner lol!

I can understand it is a bit scale puzzling at first glance seeing there are some 10th scale white rally wheels and tires in the last pic holding the Escort chassis, and these wheels look almost exactly like the 5th scale MCD rally wheels of the large Impreza

FirstGenLegacy

No worries bro, it was my careless mistake, I should have read the last post thoroughly.
Yeah man, my daily driver is a 96' Legacy Wagon on Wrx suspension, '03 Wrx wheels, and more recently got the exhaust done, (borla uel headers, 2 1/4" piping, to a WRX muffler, too bad the muffler is bad and is slightly chirping!
Your wrx is beautiful too buddy.