Well.. if a part fails it's most likely too late already
Those cost practically nothing, but I'm sure as soon as you and Pat get in contact he'll know what to do
'sid
My thinking exactly. And no- the steel plate is carrying the vertical load- the very force that heim joints are not designed to handle and one of the design flaws I am trying to get across. Your design is expecting the heim joint to carry a load 90° from what it was designed for. I can guarantee failure- the only question here is a matter of time. Personally, I think that would be very short.
I guess those guys racing heavy lawnmowers on the same exact design - didn't know it can't work
http://www.g-team.us/Front_End/
I guess those guys racing heavy lawnmowers on the same exact design - didn't know it can't work
http://www.g-team.us/Front_End/
I guess those guys racing heavy lawnmowers on the same exact design - didn't know it can't work
http://www.g-team.us/Front_End/
Pat, I know.. but it's just a ptfe pad, cut small grooves for the T-nuts and attach them with longer bolts, the ptfe pad will only act as a vibration damper once all bolts have been tightened down.
I'm also quite positive that you will not be able to crack the ptfe and end up with a sturdy system to mount 'whatever you want' in a non sliding manner
the second link is just a catalogue of such sliding bearings in different sizes and with different flanges, nothing special.
That plastic is (well should be) ptfe.. the densest I know, that stuff isn't flexible at all;
It'll absorb some vibrations at best, but isn't going to flex enough to notice.
'sid
'Sid, you're on the right track with your ideas, but I have to point out some things....
The plastic is UHMW, not PFTE; Ultra High Molecular Weight I can remember and spell; the full name for Teflon is outside that...
UHMW has descent structural properties, which is why it's used in this case; Teflon does not. Teflon is so soft that all engineering applications are captured only; I've damaged (and scrapped) a 1/2" X 3" bar by squeezing it to hard just trying to get it out of thebox it got shipped in....
of competing with PEEK in strength, wear resistance, impact resistance, etc. I could leave fingerprints in it if I tried; the only way we could avoid having to work with it was to "NO QUOTE" the part. My former employer learned that the hard way when he didn't listen to the machine dept., and just tried spiking his quoted price.....Yes, and you didn't noticed, that they changed the design in the very next picture again... I get that
They have multiple designs. And I found a lot of go-karts brand using this design during my search.
Oh, I know the answer. It's internet. Due to my job I spend about 16 hours a day behind computer and participate in about 20 different forums, dedicated to my hobbies, cars, etc.
Some of them are helpful, and some... This one seem to be a bit negative to those who don't want to build yet another copy of 70 year old steel frame kart.
It's been a long time since I've seen so many judgement on any forum. Really unexpected.
I guess Poboy Kartman would have a heartattack and prediction of fail in about 2 seconds of my Spyder spindle desgin, simply made out of 1/8 steel door hinges! Yet it runs for two years now, every summer day, with no problems. My new project will be desinged about 100 times tougher for half the weight.
OK, are we talking the same exact material? The Teflon grade I've worked with in the past was mostly used in food processing applications; shavings were the same weight & consistency as Teflon tape and hasn't got a snowballs chance in
As far as plastic's are concerned, PEEK is one of the greatest to machine of any I've worked with; milling it is very similar to aluminum. Drilling & tapping is more like copper, though, which means you have to pay close attention to the condition of your cutting tools....
UHMW is pretty friendly as well; it's down side is the same as Nylon. They're both hydroscopic, which means they can change size with the outside humidity.
I've also machined a lot of no name recycled material, that was just a drag, because you never knew what the next piece was going to be like....
I'm not sure about what you've got for your example of Teflon, but I managed to dredge out an old RFQ from an old job (~5 yrs. old) that was about replacing the wear pads in a similar cross section of 80/20, and it listed the pad matl. as UHMW....
Pat
) and PE won't so I haven't had the need to have an identical PE part.
Yes, and you didn't noticed, that they changed the design in the very next picture again... I get that
Uh huh-
No - no not not no but hill no! This site is anything but that. Pull up your drawers your rear end is showing. You will never amount to the amount of intellect or experience in some of these members little fingers....You are not only full of yourself- but something best flushed.
So go on back to your cyber-world fantasies with "normal" forums- because we are as advertised here. We welcome all with open arms. We are here to help. But if you so much as step on a toe on a fellow member - I'll take you out....and you have- more than once.
So- ........
that's odd..
really.
PTFE is always PTFE but not always the same of course.
(teflon is a brand name, not the best ptfe around said my plastics guru)
it comes (as all plastics) in slight variations from shore 65 to shore 72 for example, I got one of the highest rated because my whole head assembly relies on just the ptfe part, if that fails I'm screwed
not much weight.. but I could position my head below the table by a cm or two.. and there lies some fatality in that.
Anyways, I always get my stuff at a local plastics company (reseller not manufacturer)
I can't recall the brand but it's labeled "machinable, food and chemical applications" or something along those lines.
Anyways, I also got the same part made from PEEK, it does the exact same job for me for almost twice the cost
I just noticed, that the PEEK part had a dent from my fingernail, so I assumed it's weaker than PTFE (no way I can scratch it with my fingernails..)
But you're right, it's nicer to machine than PTFE, but I need a tapped hole and I'm done.. so I haven't payed much attention to that in detail.
ALL PE materials are out,
since the part needs to withstand a certain amount of heat (the toolehead is for melting ABS.. so yeah
I do have some machined (HD)PE parts however and although they're good for what they are, they are crap compared to PEEK or PTFE.
Again, if 'your' UHMW is 'my' UHMW (PE and not some other more fancy plastic)
it should be closer to HDPE than to PEEK or PTFE.
But hygroscopic?? that makes me wonder ... HOW?
PE itself is hydrophobic, that's why freezer bags are made of PE mostly,
or what I often use: large plastic cutting boards,
cheap, reliable and in "butchers" versions thick enough for more serious parts
One might be UHMWPE but I consider it to be HDPE, although it beaves slightly different, but it has the same specific mass.. and frankly I don't care much
to have a hygroscopic effect you would need to add talcum or something.
I can't imagine a reason why you would want that..
but I'm sure there are some that I just don't know of
Anyways, HDPE (UHMW..) PEEK or PTFE, no matter what the pads are made of in that bearing,
if they do not withstand the load it's easy to make steel or aluminium pads,
since it doesn't need to slide much anyways
'sid
Pat
wrong answer.
Tell me about it, I'm a code monkey myself, my first ICQ number had 4 digits and started with 11...
)It's been a long time since I've seen so many judgement on any forum. Really unexpected.
I guess Poboy Kartman would have a heartattack and prediction of fail in about 2 seconds of my Spyder spindle desgin, simply made out of 1/8 steel door hinges! Yet it runs for two years now, every summer day, with no problems. My new project will be desinged about 100 times tougher for half the weight.
