So, what do you think of this design?
as it's the one I'm probably going to make.
Attachment 4278Attachment 4277
Thoughts and constructive criticism welcome.
It's made out of 10mm thick ALu by the way and 20mm supported rails.
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So, what do you think of this design?
as it's the one I'm probably going to make.
Attachment 4278Attachment 4277
Thoughts and constructive criticism welcome.
It's made out of 10mm thick ALu by the way and 20mm supported rails.
Hi, what do you intend to use the mill/router for? What is the cutting area?
Regards
A 1050watt Kress at the moment, Cutting Area it just over A3 and 100mm High.
I like the triangles, you get a lot of strength from a triangle.Quote:
Originally Posted by jcb121
Can I suggest 2 small changes.
The X axis rails have a lot more vertical separation than there is separation on the ball bushings. This introduces an awkward turning force on the nut which the bushings are poorly placed to resist. Suggest you lower the top rail and screw somewhat. Allow the Z rails to overhang at the top you are only going up there for tool changes, keep the strength at the bottom where you need it.
Bolt the vertical risers to the sides of the Y axis aluminium sections. Connect the diagonal braces to the vertical risers with a lap joint not a mitre. Using an offcut from the vertical riser as packing, lap joint the braces to the aluminium sections. Maximise the rigidity the diagonals have to offer.
Incidentally, 1/2" thick aluminium bar is a lot easier to find than 10mm.
I think the Y-axis rails should be mounted on something stronger, ideally both on a single piece. At the moment they're on something that will twist easily, so they will still deflect downwards...
Having them far apart is good I think, though I agree the ratio of the Y and Z rail seperations should be closer to one. Perhaps make the Z axis wider?
I have just received my DIYCNC Breakout board! :D
this may sound silly, but this is the first serial item I have ever used! I have to find an old PC now!
Also took delivery of some M6-M12 taps.
Exciting stuff.
The supported rails in that picture were 250mm Long and the screw was 350mm, this allowed me to mount the screw supports above and below the supported bearings making it thinner.
I'm now getting 300mm supported rails, this means that the screw supports will have the be inline with the rail and that the Z axis will be wider.
would changing the ratio of Z and Y closer to 1 make it more rigid? I thought it was a bigger the better situation!
the ratio of the new design is about 2:1
the 2 being the Y axis.
I think that ratio is fine as both of the distances between rails are reasonable, so it surely can't be worse than if they were both the same as the 1.
What are you mounting the Y-axis rails on?
probably one large bit of Alu. due to the cost of this, i'll have to make the Y Axis rails closer together to make it cheaper! then it probably will be very close to 1:1
Any one know where I could find ALu 170x10x....
I'll have to check down fromstock later today :)
One large piece is best, otherwise the rails will twist.
Try www.aluminiumwarehouse.co.uk
Imperial dimensions are more common, so you're after about 7"x3/8"... these are the nearest:
http://www.aluminiumwarehouse.co.uk/...ducts_id=29030
http://www.aluminiumwarehouse.co.uk/...duct_info.html
I genuinely didn't realize that they had more then 1 page. I thought their biggist was 20x40! I didn't even bother looking for page numbers!
I can get away with using 6"x3/8"x... it's £15 for 1000mm so it should be more then enough. any metal above this size gets very expensive very fast!
I'm going to have to file the supports for the rail to allow the screw supports to be placed. I can live with that.
Box/rectangular section would be stronger if you can find a bit the right size.
I think Chip used the 6"x1/2" for his gantry ... it was definitely something close to that.
The 6 Inch stuff will be 10mm to thin. it's either get something 10mm wider or knock 40mm off my cutting area!
That's annoying as the next size up is 10" then 12"... if you decide to get the bigger size which has to be in a 2m length (I phoned them and they said they don't sell smaller) I might buy the spare from you. For a good price :lol:.
the only way I could make it work with 6" would be to mount the supported rails on the very edge of the alu and filed down the screw supports.
I'm talking 1mm from the edge of the hole to the side of the alu.
If i went for 10" it would be silly as my Z axis would be so wide it would be worse then using the 6" with the rails mounted properly!
Can you drop down to 6" x 3/8"?
A lot more cost effective.
http://www.aluminiumwarehouse.co.uk/...duct_info.html
Somebody's not been reading the thread again :whistling:... he said that in post #11Quote:
Originally Posted by John S
Get the 10" and cut it? Or maybe get it delivered to me, I'll cut the edge off on my router and keep the offcut as payment...
This is wgat I'm talking about:
PCPPS v3.0
I was planning on getting the 4 axis one from Zapp but he was out of stock. I'm sure this one will do just as well. I'll be using DIYCNC drivers as well.
how is this for Z and y?
no snide remarks about it floating! :)
I'm not sure on the exact spindle size so it is mainly guess work :(
Quote:
Originally Posted by Jonathan
That's me not reading page number this time :D
I think you should go for the wider aluminium. It's annoying, but it won't hurt to have the Z axis a bit wider/stronger. It looks like you're using the same aluminium for Z... I'd make it stronger by putting the linear rails on the bit that moves up and down and the bearing blocks on the piece fixed to the gantry. That also saves a bit of aluminium/weight.Quote:
Originally Posted by jcb121
The stepper motor mounts have poor torsional stiffness...I'd either use bigger bar or plate or something.
Looks suspiciously like my spindle mount in the drawing :)
Wingardium leviosa.Quote:
Originally Posted by jcb121
it was your spinde mount, I tweaked it a bit.
The steppers will be mounted properly, that is just there for show as I cba drawing a Mount.
I'll give a go Jon, but I'm destroyed at the moment.
I got a new Motorbike today, I was so excited I couldn't sleep last night. so I didn't.
I'll to the metal shop tomorrow and see if they can do me a deal on some properly sized alu.
good luck JCB
on the deal that is :)
James
I've found some 180x12x80cm for £20.
not an excellent price compared to alu wharehouse but i'm not going to pay shipping so it's worth it.
Jcb
how is your build going have you made your bed yet (I sound like your mother LOL)
James
it's going ok, My mother bought me a new 125 on monday. It's an RG125 1994, by tuesday, it's broken.Quote:
Originally Posted by luke11cnc
so I have to split the engine, new gaskets and seals etc.
I'm going on holiday on the 13th and I'm waiting for my stuff from my man in japan (I wish japan!)
I'll probably start after my two week holdiday in newquay :)
owch! i bet you were ringing its neck in first gear... buy some extra seals and rings... it'll need doing again by wednesday :rofl:Quote:
Originally Posted by jcb121
I had to but i didn't in first! there was no power in the bike at all! if anything they were riding it with popped seals.Quote:
Originally Posted by blackburn mark
I also discovered that the piston hit one of the powervalves! so they are screwed and they cost £130 each!
[QUOTE=jcb121;23237]I had to but i didn't in first! there was no power in the bike at all! if anything they were riding it with popped seals.
QUOTE]
allways a risk when buying a second hand two stoke... especialy an RG:naughty:
£130!!! times have changed :confused: highly strung two strokes are murder for self distructing in first and second... i managed to melt an RD400 three times in the space of 500 miles(way back in the day when pistons and rings where cheap and power valves hadnt been invented)
if you let the motor reach its rev limit in first and second (ish) because of the low speed ergo low wind resistance and drag, the whole drive train goes slack and im pretty sure any lash in the motor causes enough vibration for the piston skirts start slapping against the liners, a bit chips off the skirt causing an imbalance causing more slapping and it quickly cascades into a disaster
over reving is much less important at 30mph (ish) and above as the wind resistance keeps the drive train nice and taught
grr it has to be done this week!
i need to ride to my MOD 1 on monday.
i just did a bit of research on the powervalve (i never got my hands dirty on one) if the bike was a bit guttless after 9000rpm (start of the powerband) then the chances are the powervalve wasnt working in the first place... some versions aparently wear out and can drop parts into your cylinder, possibly what happend to yours ?Quote:
Originally Posted by jcb121
if you have all the other replacement parts it may well run well enough for your mod 1 without the powervalve running (i think you can assume it wasnt running anyway)
good luck man :sad:
Mate, you are almost spot on!
It was gutless all the time! I barely had the power to move me from stopped, I would have to clutch in and rev it again 2-3 times.
The power valve was working, I saw the servo moving about.
when I took apart the engine, the piston was worn to a smooth edge on one section. The power valve has fallen into the engine and it closed off half of the exhaust completely, as well as that the bottom end is leaking pressure.
this would explain how crap it was riding!
The powervalve hasn't completely fallen out of place though, i can still move it physically up and down with out issue. the power valve is in 3 sections and I think just the middle one has fallen down. this would also explain the rattle I heard when riding and the worn piston.
TheTuningWorks have a set of two blades for £250 that i will be buying tomorrow with weekend delivery.
I need to find some good liquid gasket though, the manual states suzuki bond 1215 but I can't find this stuff anywhere and it's a bit late now!
might be worth bending some ears in a local bike shop,,,, not the pocket rocket supermarket type where the staff dont know what oily hands look like and would love to sell you some super duper suzuki bond 1215 for £60Quote:
I need to find some good liquid gasket though, the manual states suzuki bond 1215 but I can't find this stuff anywhere and it's a bit late now!
id be looking for some ugly bugger with a beard and oil tattood into his hands... im sure he will have a nice equivelant in a dusty box for a tenner :)
I'm guessing you'll be needing a sealant that's flexible and actually sticks things together (not like the usual silicon gasket stuff, which doesn't really glue anything together, just fills holes).
Genuine Ford and Vauxhall sealant are good, and reasonably cheap (Ford stuff comes in a handy little dispenser tube, whereas Vauxhall comes in a short mastic tube and needs a mastic gun). Failing that, Tigerseal is always good, but may make future dismantling a bit more challenging!
that sounds like the type of stuff :smile: ..... you wouldnt happen to have a beard and tatto's on yer face would you M_C ?:smile:Quote:
Tigerseal is always good, but may make future dismantling a bit more challenging!
I don't have a problem with dismantling it! I have all the tools needed to split them.
I genuinely couldn't get the cylinder off though.
on my 2nd day of riding the bike, I went to my metal shop to price up some alu for my cnc, went there today and said it was broken. he genuinely looked sad and gave me some steel and bolts for free.
he just told me to get the bike running!
I drilled holes for the cylinder studds in the metal and drilled a central hole. I had a 100mm bolt to push down on the piston and pull up the cylinder.
marked the piston badly but it was scrap anyway.
thinking about it, i should have picked up some alu at the same time and started to build my CNC on the cheap!
Sticky is ok, It has to be strong mainly. it needs to withstand oil, coolant and high pressures from the bottom end.
Tigerseal is just a brand name for PU (Polyurethane) adhesive, and is used in the motor industry for sealing/sticking car panels on. It relies on moisture to set, and once set nothing other than physically cutting it of will shift it. Just make sure you wear gloves when dealing with it, as if you let it set on your skin, it takes a good few days for it to eventually fall off.Quote:
Originally Posted by blackburn mark
And no tat's here, only stubble!
Although I am known as the grumpy one at work...
I don't think i'll need anything that extreme!
hahahaha! i was thinking that.... im going to store that one in my memory though, Polyurethane adhesive.... might come in handyQuote:
Originally Posted by jcb121