Another (UK) source for M4 insert used in Adrian's geared extruder? (SOLVED)

Hello All

I wonder if anyone has identified another source for the M4 insert used in Adrian's geared extruder rather than the suggested source here. They charge MORE for UK than Europe and the postage is higher than the cost of the item!!

That's just taking the piss.

Any other more reasonable priced sources would be appreciated.

Cheers

Edited 1 time(s). Last edit at 03/18/2011 07:44AM by AgeingHippy.

You could do like the labitat guys and wreak havoc on a few m4 nuts with a dremel.

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-Nudel
Blog with RepRap Comic

I have always called them nutserts, maybe screwfix ?, the drawback is you will maybe have to buy a box full?.

This kind of sourcing issue is a good reason to determine costs and sources of all the parts for your entire RepRap project first, including sales taxes and shipping, before buying anything significant -- then you will know more clearly what is involved, and you can do your best to minimize your shipping costs, reduce your total number of vendors, etc. You'll still make a mistake or two, being human (!), but at least you'll have tried to minimize your costs and your surprises.

I note that if you buy 24 of these "M4 insert"s from Conrad UK, at GBP3.13 each, your order total will be over GBP75, so they will offer you free shipping. Then you could, in theory, resell the remaining 20+ (keep a couple of spares!) to other UK Reprappers, and charge them whatever low shipping charges you think are appropriate

I suspect the reason that some parts are cheaper from Conrad on the mainland of Western Europe is that conrad.de is (as I understand it) the parent company, so larger and higher volume... I'm guessing, but this makes more sense to me than your explanation of this phenomenon!

BTW, the sourcing issues surrounding this particular part are one reason I decided I'll be going for a Wade's extruder rather than Adrian's -- I can (I hope!) mess with a bolt in a vice and a hand drill and an M3 tap, and generate several "hand-made" geared parts for Wade's design, for less than the price of buying one of these parts and getting it shipped to me. I have not done that yet... but that's my plan at the moment. Right now I'm wondering what design changes will show up in Wade's extruder to allow it to use Adrian's newest hot end nozzle design. I still have plenty to do assembling a Mendel, testing electronics etc. before I run out of RepRap related project work and need to truly commit myself to a specific extruder/hot end nozzle design. Before I commit, I'll have a list of all the parts I think it will need, and know where I plan to purchase them and what they will cost.

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Jonathan

Hey people

I think I have found an alternative resource for the M4 insert. hobbys in South London sells what looks like the business. Of possible importance is that this insert does not have a locking grub screw and the base is hexagonal not round.

The web site does not have any photos of the insert but I have just been down to collect it and it looks pretty much like the one supplied by Conrads. Price for the insert is £1.95 and shipping (to UK) is between £1.40 and £1.80.

I will leave an update here once I have constructed the extruder and tested. Don't hold your breath though as I am relocating to York and construction may take some time.

Cheers

Edited 1 time(s). Last edit at 06/24/2010 05:39PM by AgeingHippy.

Found a Better place to buy from and they ship WorldWide . Also it is cheap to ship to the USA, only cost me 2.85 Euros . They are new and there prices are more than far. Check them out


[www.mendel-parts.com]

Cheers,
Mark F
2Robotguy

I tried using 2 nylocs like the Labitat guys did and it didn't work very well for me at anything but very low speeds. At higher speeds they just didn't seem to have enough grip, and the gaps made by the dremel completely filled in with plastic which effectively smoothed the surface and reduced grip even further. If I'd played around with it enough I might have been able to get a slow print, but to be honest I could have saved myself a lot of hassle by simply mail ordering in the proper M4 insert.

I'd be very happy to be proved wrong if the Labitat guys or anyone else can offer any advice on getting nylocs to grip properly.

Sorry, I should have posted an update as promised in my previous post regarding the insert from hobbys in London.

It seems to be working fine. I tighten the nuts tightly and there is no slipping so the fact that the grub screw is missing does not cause a problem.

The hexagon base is not a problem as its max diameter is less than the diameter of the bearing.

All good so go for it.

(I cannot check the link is still working as my work has recently established a draconian sledghammer web filtering policy and for some reason that page is blocked. fwiw - it blocks the botmill page calling it a hackers site and some other page has been blocked as a gambling site!! but I know it is not)

Thanks for the update. I'm going to have one more attempt at getting nylocs to work, just because I'm stubborn. I'll post my results here again.

I feel your censorship pain. My company recently blocked Hackaday for about the third time because it's a site dedicated to "hacking" which, as we all know, means breaking into computer systems.

Muppets. All of 'em.

I take it all back! I've been printing for a few days now using a pair of nylocs and I've been getting good results. Not as good as other prints I've seen, but that's probably due to other factors. What I did was place the nylocs in a vice grip and then take to them with the edge of a sanding disc:

[tinyurl.com]

This type of disc is quite resilient and causes the nylocs to glow red hot and shoot out lots of sparks. I also tried a different disc type that was brown and seemed ablative, it worked fine but wore down during the griding (good thing they're cheap). Eight evenly-spaced notches around the nyloc and a quick touch of the disc on the flat areas between the notches to rough it up a bit and the job is done. The plastic seal inside tends to disintegrate, I scraped it all out with a small screwdriver. Place two of these nylocs on your drive shaft along with a regular M4 nut and you've got something similar in shape and functionality to the M4 insert.

That said, I did find that they don't grip as well as a hobbed bolt that I happen to have lying around, so I had to make some changes to get them to extrude well:

- First I had to raise my nozzle temperatue to 220, at 200 it came out too slow and too irregular (I'm printing PLA btw). There's a possibility that my extruder is running a bit cold to begin with, but it makes sense that a hotter temp would require less effort to push out.

- Next I raised my extrusion e-steps-per-mm by about 35% i.e. from 17.6 to 24. Again, I think this probably just helped compensate for the lower grip.

- Finally I had to remove the spring-loading. I'm not quite sure what was going on here, either the springs were too loose and the nylocs couldn't get enough grip or they were too tight and caused the nylocs to grind into the plastic and then start to slip...I suspect the latter. Either way I had to get rid of them and simply use hand-pressure to tighten the nuts that hold the extruder together.

The combination of hotter nozzle temperature and faster extrude speed means the extruder isn't terribly good at stopping the flow of plastic, so I find it's pretty important to make sure that the little L-shaped wipe piece at the lower left-hand corner gets laid down correctly at the start of the print. Overall though I've had few very problems and I've managed to successfully print out pieces ranging from the 2cm 11-tooth drive-gear up to larger pieces for a Wade's extruder.

Edited 1 time(s). Last edit at 03/24/2011 06:20PM by Myndale.

hello

I've just ordered an insert from Maritime Models

It cost £3.19 including postage and packing.

Michael