Hi guys bought some drills today, took them apart and they luckily still work! Soon ordering some 15mm HDPE and trying to get my robot up and running ASAP.
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Hi guys bought some drills today, took them apart and they luckily still work! Soon ordering some 15mm HDPE and trying to get my robot up and running ASAP.
Bougth some plastic yesterday, getting it early next week.Getting a bench drill from grandad soon and going to get my robots chassis resdy in the next few weeks. Can you put a nut to make 125mm blue wheels with plane bore into 125mm blue wheels with nut insert?
you should beable to i would put 2 in each heat them up and press in
remember they are 3/8 UNF thread
Another way is to weld a washer to the nut and bolt it on the wheel!
Thanks for the advice, if I was to melt the nut into the wheel how would I do it?
Drill the wheel out to a mm or so under the distance between opposite flats on the nut, then heat the nut up with a torch and shove it in (ensuring it goes in straight) with an arbor press/bearing press or whatever (bodge a jig using a vise I guess).
You can use two at once by threading them onto a bolt (making sure the flats on both nuts line up) and shoving the whole lot into place, this will help you make sure it goes in straight.
Got the plastic yesterday(15mm 500x500 and 6mm 1000x500 HDPE) cutting it tonight. Is a jigsaw the best way to cut HDPE if not what is?
Abrasive waterjet.
Somehow I doubt that was the answer you wanted... so of the less expensive options a bandsaw is your best bet by far, but if you don't have access to one a jigsaw/scrollsaw will work. You want to use lots of coolant (though lubrication isn't an issue, you can even get away with water) and go pretty slow, in addition to using a coarse wood cutting blade.
Problem with HDPE is the same as a lot of thermoplastics, it will soften and melt very easily from cutting heat resulting in a messy cut, bound up blade, or the material reforming itself behind the blade. Those are the best ways to avoid it.
i've found, that using a jigsaw is fine and aslong as you take your time you can get good cuts, other day i made 2 hdpe rings to hold a co2 bottle in place in my feather weight and they turned out great.-- but i use a metal cutting blade which has much bigger teeth, i found on the small toothed blades for cutting wood it takes ages and the teeth used to clog up.
never bothered with any lubricant or anything for HDPE, as any roughness which as nick said you would get from the material reforming/melting back together beind the blade can just be filed off to leave it looking smooth and you dnt have to bother getting all the lubricant off afterwards either.
but when cutting ali and other metals you do have to use lubricant otherwise you'll go through blades like nothing else.
when I was cutting the Lexan for my ant it melted, the is answer to use a saw with bigger blades.
no, if the blades clogging up, i'd say use a bigger toothed blade, any plastic material you cut with jigsaw will melt because of the heat, you can use lubricant but i'd just smooth off any roughness with a file after or if it was melting badly i'd just take it slow
but thats just me, personally im lazy and like to keep things clean where i can to save myself more time spent cleaning up lol
just to clarify a metal blade will have smaller teeth than one for wood
I have a table saw which works a treat on HDPE and aluminium (proper blades a must!!) and have seen jonno using a circular saw on polycarb, tends not to clog up as the teeth are much bigger
I used a circlur saw, which worked.
holding the poly carb when circular sawing it isn't pleasant, large chunks of poly c at high speed hitting you all over :crazy:
Don't forget to have the jigsaw running at a low speed. This will reduce (although not eradicate) heat generated during the cutting process. I find a coarse blade (bigger teeth) to be best, as has been mentioned. Don't force the jigsaw through the material, just take it at a steady pace and it will be fine. It should fly through 6mm HDPE and will also be pretty quick through the 15mm stuff.
I wouldn't bother too much with coolant for it; if you keep the speed down (maybe setting number 3, if your jigsaw goes from 1 to 6) and take it steady it will cut without issue.
got a bench saw and cut the Hdpe today tomorow cutting the top and bottom and uploading pics of what my robot will look like.
cool :mrgreen:
Yeah it's gonna beat yours!!! Havent cut the rest of plastic yet because a)I've had loads of homework b)becaus eI have to use the bench saw outside and because of rain I cant (humph(angry)). Hopefully getting the plastic cut soon.
mine will easly beat yours, for a start my robot has 2x the amout of pushing power, thicker armour and a better driver. lol :mrgreen:
Ok lads. coold down, save the aggresion for the arena :twisted:
lol
Got a bench saw a few days ago... Tested wood on it and it cut fine blah blah blah.
Made the outer frame cutting the base and few little twiddly bits got some screws.
sounds good
forgot to add I mucked up the back of the robot; once I had finished cutting I stupidly left the saw still spinning and I pulled one end of the plastic away pushing the other end into the spinning sawblade so there is a big curve one end.
ha, lol.
did you have enough plastic to rebuild it
I dont have any left over, but luckily I'm cutting the bad end off because it is too big.
Cut the plastic last night, trimming it down to size today.
Made a jig to make it all to size uploading pics of what it looks like so far.
Ordered 4 100mm blue wheels, hopefully coming today.Where is the best placed to get shafts and bearings?
presumably your getting the blue wheels with nut insert in???
what motors are you using??
My robot is 2-wheel drive, so I'm getting 2 wheels with nut inert and 2 without.
I'm using these motors http://www.homebase.co.uk/webapp/wcs/st ... 7C16849334
so are you running the other 2 wheels via a belt drive from the motors?? or are they just dead wheels ???
They're not driven by belts, they're free spinning. Bodge job came yester day and I needed some bearings. I saw his scooter and thought 'hmmm' , so I took my 10 quid scooter apart and in each of the wheels were 2 bearings.That is a cheap way to getwhaeels and bearings. But, I'm not using that way as the bearings are to big for the blue wheels.
Mounted the motors into the plastic assembling it tomorow
My robot so far, in bits.[attachment=0:2whijhdy]Big 'n' Scary, Like a LASER.docx[/attachment:2whijhdy]
Ordered bearings and steel bar from technobots last night.
These are the bearings: http://www.technobotsonline.com/miniatu ... x24x6.html
...And these are the steel bar: https://www.technobotsonline.com/silver ... 33173.html
I need a 12v battery that can power 2 drive motors and a lifter motor I'm thinking of using this battery: http://www.technobotsonline.com/haze-hz ... 2.2ah.html
Is it the right battery? If it is'nt what kind of battery is better?
That's a sealed lead acid battery. Usable but somewhat under powered. SLAs were used around 4 or 5 years ago in featherweights and were the standard at the time.
I'd recommend looking at nimh batteries instead. Something like this pack here,
http://cgi.ebay.co.uk/12V-3700mAh-NiMH- ... 3353ee4e1a
Will give you all the power you need for your 3 drill motors. I have used these packs in the past and they have been fine.
Bearings and shaft came last week. Got a bench drill over the weekend adn going to drill the holes for the bearings to fit into
Sabertooth 2x25a came today, hopefully over the weekend assemling the robot.
my robot is now fully built and running. I'm using a lesd acid at the moment, but would battery be good(it is shown in a set but i would buy the battery on its own:
http://www.centuryuk.com/ewcommon/tools ... artid=3618