[Mike F]

ViperTX,

I suppose there is not one, simple answer to your question other than, Why not? Which of couse is not an answer. However, if you have read the thread so far, you will appreciate that my design is a little 'Off the Wall' literally and as such I figured the lighter the construction the better the performance. There is no better material than carbon fibre for the combination of strength, stiffness and lightness. If you factor in my interest in composites as well, you may begin to understand where I am coming from.

I am also something of a free radical in that I do not always believe that convention necessarily gives us the ultimate designs. It is something I am keen my students learn. Conventional design is good for the majority of cases and works well but we are not exploring anything in just copying what already works. For me, this project is as much about exploring possibilities, materials, construction techniques and my abilities as ending up with a functional machine.

I happen to believe that, provided I can manufacture the parts, that a composite gantry will give me better performance than an aluminium one due to the properties of the material. Whatever the outcome, I know it will be better than the MDF prototype

Sorry if this all sounds a little philosophical but you did ask the question

Mike

[ger21]

Why would you want a gantry made of a composite material?

Stronger, stiffer, lighter, faster.

[10bulls]

I just went to order some (what I think) has been referrd to as confirmat screws...that is a large thread wood screw for 5mm hole, with a 15mm x 6mm shank and small countersunk alan key head...used for screwing wood to itself. The company referred to them as "carcass" (carcase sp?) screws. Thought this might help if someone was trying to find these in the UK.

Also, while I'm on the subject of thrashing a dead horse...
www.hpcgears.co.uk do a comprehensive line of toothed pulleys and belts.
My (oldish) catalogue only lists 3mm HTD pulleys up to 9mm.
They do 'reduced backlash' timing pulleys from 5mm pitch (ABT profile) at 10,15 and 25mm. For example, 48 tooth 5mm ABT pitch, 16mm wide - list is £22.58.
Similar in 3mm HTD 9mm wide are £9.08. They also do a nice range of rack an pinion and general gears.

BTW. Well done for trying such an different design. It would be a dull old world if everyone copied the same design over and over.

OK, I'll go back in my box now.

[morrissp]

Also, while I'm on the subject of thrashing a dead horse...
www.hpchears.co.uk do a comprehensive line of toothed pulleys and belts.
My (oldish) catalogue only lists 3mm HTD pulleys up to 9mm.
They do 'reduced backlash' timing pulleys from 5mm pitch (ABT profile) at 10,15 and 25mm. For example, 48 tooth 5mm ABT pitch, 16mm wide - list is £22.58.
Similar in 3mm HTD 9mm wide are £9.08. They also do a nice range of rack an pinion and general gears.

10bulls, I cant get that url to work, any idea's

Steve

[Mike F]

10bulls - At school, we order all our screws and fittings from Hafele. They have an on-line catalogue too at: www.hafele.co.uk Hafele certainly call them confirmat screws but as with many things, other users/manufacturers have other names - probably a copyright/patent thing.

Question - does a masochistic, dead horse enjoy being flogged?

Unfortunately, I could not open the link to HPCHEARS in your post but thanks for the contact. They are still much more expensive than the ones I got from the States but good for future reference. I wonder how much difference there is between the standard and reduced backlash pulleys?

Mike

[10bulls]

10bulls - At school, we order all our screws and fittings from Hafele....
...They are still much more expensive than the ones I got from the States but good for future reference. I wonder how much difference there is between the standard and reduced backlash pulleys?

Sorry guys, try www.hpcgears.co.uk.
They say "Never knowingly outpriced", so probably some scope for haggling...especially if you lay on the 'Educational' aspect .
They had a stand at Model Engineering Expo last year so I'm presuming they're 'friendly' to the little guy.

I too have a Hafele catalogue...but it hurts my back too much picking it up!

[Question - does a masochistic, dead horse enjoy being flogged?]

Nay! Come on...why such a long face? etc. etc.

[skippy]

Maso...confir....carc.....scre.....See what you've done Mike! I'm too scared to even write the words now. Where are you? No one's heard from you (in full swing that is) since Feb 1st. Hope all is well and hope to hear from you soon.
Skippy

[Mike F]

Skippy,

I'm still here but the machine is gathering a little dust at the moment. As I have said before, I am a teacher and can only work on the project when not teaching (the machine is not at home but in school so I cannot work on it in the evenings or weekends) and added to that, I am the examinations officer and this is my busiest time of the year so any non-teaching time is spent organising the exams.

Roll on retirement not wanting to wish my life away of course.

Thanks for the concern - I do keep looking in from time to time and I promise it won't be too long before building is recommenced.

Cheers,

Mike

PS In the evenings I have been building my own electric motors which has been fun.

[Mike F]

Well, it's time to get this project back on the road. I'm still in the middle of the examination period at school but there may be just a few gaps in the busy schedule when I can dust off the work so far. You won't believe the ammount of dust this thing has collected over the past three months

I've just ordered three Gecko 320s and will have to start thinking about power supplies also and breakout boards. I notice the Campbell boards also require a relay board before it can all be hooked up. Are there any boards with relays incorporated?

I am really looking for Home and limit switches on all three axes, spindle on/off, extraction on/off and coolant on/off - maybe even spindle speed control. Any help much appreciated.

It's good to be back.

Mike

[HomeCNC]

Campbell makes a nice board. Also cnc4pc has a modular approach that I like.

[Mike F]

Jeff,

I have looked at both the Campbell and CNC4PC web sites but am still confused. As I have said many times before, I have no electronics knowledge and trying to decipher exactly what I need from the electronic jargon is nigh on impossible.

The Geckos are ordered - do these plug into a parallel port interface board, a breakout board or what? If I then want to add limits and home switches, are they on the breakout board, interface board or is this another board? I then want to control spindle, coolant and extraction. I believe this requires a relay board - where does this plug in?

Aaaaaaargh - Maybe I've bitten off too much and should just sit back and admire the unmoving machine :drowning:

Mike

[Mike F]

Jeff,

Have you had a chance yet to review the CNC4PC boards yet?

Mike

[Mike F]

FANTASTIC :banana: :banana: My Geckos have arrived already - only ordered them last Thursday!! Thanks Mariss, most impressed.

Now I really must tackle the power supply and breakout board issues.

Marc (Coherent), I've been trying to weigh up the pros and cons of the three suggested breakout boards, PMDX-120, CNC4PC and Campbell Designs. You are happy with your PMDX - do you know whether it will support a 220VAC supply? I have emailed all three suppliers with the same question and only had a reply from Campbell Designs (a bonus point for them ). Campbell Designs say they have a jumper that can be set for either 120V or 220V.

Jeff (HomeCNC), same question was sent to CNC4PC without reply. Can you help there also?

Going to go and press my electronics friend into a bit of action now on the power supply - won't it be good to get those motors spinning?

Mike

[Mike F]

Got a reply from Arturo Duncan at CNC4PC and he also confirms that his products support 220VAC. His range of boards certainly seem well priced. I just have a slight doubt about the capabilities of the relays to switch 220V for spindle, extractor etc.

Does anyone else have experience of using CNC4PC products, apart from Jeff (HomeCNC), and can offer any help?

If the relays can't hack it on 220V I am considering using the Campbell Designs relay board with CNC4PC's other boards. Should be OK shouldn't it?

Mike

[tag1987]

Mike you might want to look at the breakout board made by
Olivier ADLER in France. I got a quote from him last month and it
was "380 euro assembled and tested, with manual and I/O
schematics". He's at [email protected]
It's not yet available in the US so I will have to wait but it
looks good. Olivier is real active in the Mach2 Yahoo forum:
http://groupyahoo.com/group/mach1mach2cnc/

Campbell designs.com/ gets real high marks for support too.
Seems always eager to help.

As usual I have no interest in the products or companies but appreciate
good engineering and mfg's willing to support their products.

I like your design..how's it coming? A little like the Italian routers common
in the wood working industry. Do you have any recent pictures?
Jim K

[Mike F]

Now had a reply from PMDX and they can also supply their 120 board configured for 220VAC. So, it's just down to choice now.

I have also emailed CNC4PC to see if they can supply uprated relays for switching 220VAC as the solid state ones on their relay board may be a touch on the light side - we wait and see.

Jim, thanks for the interest and the link. I shall investigate and report back.

Not much done on the mechanical side since February , far too much work to do in school :tired: However, now I've begun gathering the electrical bits and pieces, there will be some progress to report on - expect a lot more questions, I'm no good with electrics. I may even get a bit of time over the next three weeks to do a bit on the machine too - I'll post as soon as there is something to report.

[Mike F]

Got a reply from Arturo at CNC4PC about the relay board, he says "Sorry for the delay in getting to you. I had crazy days around here. You are right about the amperage at 220, had not thought about it (I know I should have). I will clarify this on the website. I am going to offer individual relay boards as of next week. They will come with a larger amperage thanks to your suggestion."

Sounds like pretty good service to me and at his prices, I think he may well be getting an order.

Jeff (HomeCNC) are you still looking in? Any news on your review of CNC4PC boards?

Mike

[Mike F]

CPU coolers arrived today and with a little bit of judicious bending of the retaining clips, they fit the Geckos perfectly. At just £1, a time I bought eight. The idea being that at that price it wasn't worth buying just three as the postage worked out more than the coolers, plus I may just want to add a fourth drive at some time, plus 100% redundancy - total outcome eight coolers. I also bought a tube of silicone heatsink gloop for a grand total price of £17 delivered.

I have to thank Cyclone for the great thread on his control box http://www.cnczone.com/forums/showthread.php?t=10680& I am attempting to emulate his build.

Mike

[Jimmy Southern]

Hey Mike!

I've been following your thread. Love the idea.

Just wondering how the pogress is coming. Give us an update, because if you don't I am going to fall off the edge of my seat. This thread has been a serious cliffhanger. :stickpoke

Keep the posts coming!
Thanks a Bunch
Jimmy Southern :withstupi

[Mike F]

Jimmy,

There has been some progress and you are right, it is time I did an update.

The CNC4PC boards have arrived - I ordered a parallel port interface board, safety charge pump, mini power supply and a solid state relay board. The four boards look fine but I have not yet managed to check them out. However, the parallel port interface card supplied was the wrong one, I had ordered the opto-isolated one but the bi-directional one was shipped and this one is not opto-isolated. After some discussion with a very good electronics friend of mine, I decided to keep the one sent as apparently there is very little chance of any damage to the computer the way things are set up. It remains to be seen whether this was a wise decision or not.

I also have an enclosure to put the whole power supply and control cards/boards/geckos in. Although this was a little pricey at £90, I felt this was justified as the machine will be used by pupils and I do have to make sure things are just right. I probably could have found a cheaper one somewhere.

As you are aware, having read through the thread, I can only work on the mechanics while at school and it is now the long summer break here in the UK so there will be no more progress on the actual machine. However, I did bring all the electronics and the enclosure home so I can work on it during the break. This means I should be able to post some more progress reports and photos as the control box comes together.

Mike