[Agro]

Hi all,

Anybody had any luck getting Delrin or HDPE sheeting for making the alignment blocks and backlash assemblies in a jgro CNC ?

I can locate almost everything else I will need.

Cheers
Agro.

[Rodm1954]

It might help if you say what state you are in. I have seen it on ebay a few times and you could try your local bearing supplier. Otherwise I hope somebody else has a better suggestion for you.

[Agro]

Good point...

NSW/Sydney. I'll call Dupont this week and see if they will deal retail - here's hoping.

Cheers
Jason.

[Agro]

Good point...

NSW/Sydney. I'll call Dupont this week and see if they will deal retail - here's hoping.

Cheers
Jason.

[andy_ck87028]

Hi Jason

Looks like we're having dual conversations here (We're also PMing on stepper motors)

I have found an acme supplier in Melbourne and at their workshop they were raving over using vesconite for the acme nuts.... self lubricating...easy to machine.

I checked out a local supplier for 20 vesconite bushes 30mm each in length and 25mm diameter and they quoted $500 + GST !!!!!!. I then rang the local manufacturers of vesconite (also in Melb www.vesco.com.au) and they quoted $76.50 for a 1 metre length. You can guess where I am going !!!!

Anyway, I have been thinking about buying the acme and then getting a machiner friend to turn the vesconite for me.

I am wondering if we can put our heads together and organise a cost effective acme nut production run.

Fyi, vesconite also comes in plates, rodes, tubes .... obviously it needs to be researched / understood before applied

My understanding of vesconite is that it is a first class material for this need.

Andy

[Agro]

I'm not familiar with the product, so I'm not sure of the suitability. I haven't bought the lead screws yet, so Acme is an option which screw size did you wind up getting ?

I was planning on using the HDPE for the adjustment blocks (stronger than MDF) and the anti backlash blocks. I thought it should be possible to make the block by drilling out and fasioning a home made 'tap' out of a length of the lead screw. It will be hard work cutting the thread but should be doable.

The vesconite may do the job. What are the dimensions of the sheet for $76 ? (I.e. Enough for all of the alignment blocks and backlash assemblies) ?

I just managed to pick up a complete triton workbench and router table for a good price (second hand), so I'm not far from being able to cut the MDF parts for the CNC. Of course it will be a couple of months before I can buy all of the electronic components :'(

I am planning on using the constant current drives from Oatley Electronics to run the system. From what I have heard the stepper performance is considerably better than over other solutions (ballast resisters, unipolar etc). The price isn't bad either.


Cheers
Jason.

[Agro]

Here's a cheaper option...

The delrin and acetyl sheeting is rediculously expensive (>$200), however the acetyl rod isn't all that expensive, i.e:

45mm diameter 300.. long A$21.75.

That would be enough for the anti backlash assembly, mounted inside an MDF block. 300mm would be enough for all of the anti backlash bearings on the CNC.

http://www.smallparts.com.au/

*Lots* of bearings and bits. Some overly expensive, some not too bad.

Jason.

[tomcook]

came across this thread and sorry but i have to butt in
andy whos the acme supplier? do they have a website?
cheers
tom

[Agro]

The vesconite looks the deal.

Any idea how hard it is to cut/drill/tap ?

Cheers
Jason.

[andy_ck87028]

Tom

r u the dude who was trying to source in the UK because of relatives? I know someone from over the ditch was asking acme questions a while back.

No website for the acme but I do have a telephone number. The guy who runs the place (Matt) is an absolute gem. Mikie (also on the zone) gave me the connection. The acme is all turned and not cast so the precision is higher. Matt's number is +61 3 9354 2588. If you need anything non stock, he will need a fax +61 3 9354 6760 with a drawing before he will quote.

Matt will supply bronze nuts or will cut from vesconite if required. Tolerance needs to be specified (I need an engineer over my shoulder to quote the tolerance I need ... all I can state is stiff or sloppy lol)

Re. posting, I believe Matt will look after you and pack so there is no risk of bending but you will need to talk to Matt direct about it.

I cannot comment on Vesconite as an authority but welcome an independent engineer to throw in a few penny worth. If it is good then great but there must be pitfalls also.

Andy

[RotarySMP]

A good source of engineering plastic (not sure which flavour it is) is Ikea. Those plastic cutting boards they sell are dirt cheap.

[Agro]

!!!!!!. I then rang the local manufacturers of vesconite (also in Melb www.vesco.com.au) and they quoted $76.50 for a 1 metre length. You can guess where I am going !!!!

Are you sure on the price??

The quote I received had an additional zero on the end of it What size were you quoted on - I'm guessing it wasn't a full sheet.

Ikea sounds the goods.

Jason.

[tomcook]

yep im the dude
thanks for the info ill give them a call if this other one doesnt work out
i must have tryed 5 different suppliers had no replys or the shipping cost was 3 time tehe cost of the acme (chair)
thanks
tom

[andy_ck87028]

Jason ... Re. Veconite. My recollection .... tube of 25 mm ext diameter and 15 mm int diameter length 1M $76 + GST. Note tube not plate.

Tom ... glad you made the connection. It was in the back of my mind to send u a PM when I visited them and I actually asked Matt re. postage with you in mind but not recalling which of the 11,000 CNC members you were! Matt is good. Genuine, helpful and not out to rob ... good luck

Andy

[Agro]

Ah - that's more like it...

Acetyl is a lot cheaper in the tube as well - $21.75 for 300mm of 45mm diameter. I think I will go this way as I am trying to save some money on this.

Cheers
Jason

[Celtichawk]

Guys,

Used to get my plastics stock from Eplas in Brisbane.
Got some offcuts of all sorts, Nylon, Acetal, HDPE, UHMWPE etc.
Unfortunatly Eplas are now shiping all offcuts down to their Melb place.
I might have to try City plastics from now on, for small amounts RS components sell a varity including machinable ceramics.

Gavin

[wjfiles]

Hi All,
In Brisbane I found that "Ludowici" have almost every type of plastic.
They have plastics for bearings with built in lubrication.
Bar stock and many manufactured bushes and parts.
They are also a great source of technical info on the applications of variouse plastics.
wfiles

[High Seas]

I'll be back in "Bundy" in a few weeks, Brisbane on 25/6 june. There's a bearing shop in Bundy that sells "cut-off's at real good rates acetal etc. Else, I'm bringing a 4x2 x2ft block of UHDP for a project (mount a wind steering vane) and may have some off cuts too. drop me a PM and we'll chat on my return - :cheers: jim