Liftoff (FW) build diary

[Revsmin]

Re: Liftoff (FW) build diary

I've already done the GR-01s, and I'm working on other components. Search for them in the workshop.

[Liftoff]

Re: Liftoff (FW) build diary

Maybe we should open a new topic and make a sticky....then all post and link their components there...
I've uploaded the sabertooth esc... don't think I need to upload the GR02 now

[Ellis]

Re: Liftoff (FW) build diary

I put a GR02 up there and have loads of other components that could go.

[Liftoff]

Re: Liftoff (FW) build diary

So I've dismembered Liftoff and got it to a shell again in preparation for the rebuild - one thing is bothering me tho. When I first put it all together I used normal chipboard wood screws to join the HDPE parts together - now I'm not convinced they'll re tighten as much as they used to do.

I had read somewhere on the forum that you could use wood inserts for better results. Now I've had a look on ebay and found what I need, just want to know what size you recommend, I'm using 10mm HDPE so the insert must fit within the thickness...

These are what I was looking at these two, both fit within the thickness, but the screw size is different

http://www.ebay.co.uk/itm/M3x12mm-Slott ... 3f0c4473b0

or

http://www.ebay.co.uk/itm/M4-x-10mm-Unh ... 4169c14f67

[plargen]

Re: Liftoff (FW) build diary

I've used the m4 1s before and they seem pretty good at holding the first bot together dropped it a few time and it stayed in 1 piece

[Liftoff]

Re: Liftoff (FW) build diary

I'll go for them then, I'm just using them for the removable access panels - plan to weld all the rest...

[Eventorizon]

Re: Liftoff (FW) build diary

Those are for wood! They won't work in plastic!!!

These are designed for plastic...

http://www.ebay.co.uk/itm/M5-BRASS-I...item4d01fc65a2

You can get ones with flanges or without. You just press them in. I drilled my holes fractionally smaller and then heated them to give them more bite but the principal is the same.

[Liftoff]

Re: Liftoff (FW) build diary

Good you mentioned that Alex, otherwise I would have bought the wrong ones

didn't cross my mind there were ones specific for use on plastic!.... thanks for that :wink:

[Max]

Re: Liftoff (FW) build diary

I imagine that the inserts for wood would work fine in hdpe as normal woodscrews work fine and it tends to work in a similar way to wood with chisels and saws etc.
I would also imagine that the wood inserts would stay in better when they had the force of a bolt pulling on them or an armour plate is getting ripped off.
just my opinion, I imagine both types would work.

[Eventorizon]

Re: Liftoff (FW) build diary

No, cos I got the wrong ones. The wood ones in HDPE either don't go in at all or over stress the threads so much that they pull out with a bit of a tug.
The ones designed for plastic, I haven't been able to pull out, even when I have wanted to. Yeah, don't put them in until you have to and you are sure!

[Max]

Re: Liftoff (FW) build diary

No, cos I got the wrong ones. The wood ones in HDPE either don't go in at all or over stress the threads so much that they pull out with a bit of a tug.
The ones designed for plastic, I haven't been able to pull out, even when I have wanted to. Yeah, don't put them in until you have to and you are sure!

oh, my bad! just ignore me.

[plargen]

Re: Liftoff (FW) build diary

there are a few kinds that you can get for wood if as ive got the wrong version before you need to get 1s with what looks like an screw thread on the outside

the 1s in you links should work fine as there similar to what ive used before

[Liftoff]

Re: Liftoff (FW) build diary

Ok thanks to everyone for your input, much appreciated.

I have also found this : http://www.tappex.co.uk/ which gives a good explanation of which to use where.

[Liftoff]

Been abroad for some weeks so I had to abandon the build for a while... Now that I'm back home I can go about putting the pneumatics together and hopefully give it a test some time soon.
I'm replacing most components from the previous set up which had an empty weight of 3.7kg. The new set up weighs in at 2.6kg, that's a weight saving of 1.1kg, not bad eh!

Flow should improve as well - I'm using a different type of QEV which I had to modify to fit in limited space available (basically I had to plug the inlet and drill/tap a 1/8bsp inlet at the side) The smallest restriction from buffer to the ram will be 11mm as compared to 8mm of the previous setup - that should in theory help as well...

Some photos of old vs new QEV, old weighs 310gr, new weighs 120gr

20130501_202804.jpg

And connections from buffer tank to ram

20130501_203140.jpg

[Liftoff]

Did some testing this evening, and I'm happy with the results. Pressurised the system to 5 bar (need to buy myself a proper compessor for higher pressures ). Was a bit concerned whether the 5/2 way valve would work properly, its miniscule compared to the rest of the system was worrying me! but I confirmed that it does not affect in anyway the flow through the system.
I can now turn my attention to the rest of the build.
Video in action