<html><head></head><body><p dir="ltr">One other thing to consider is that you can 3D print in a material meant to be consumable during investment casting. In that case, instead of making a mold (cope & drag) for sand casting, you just 3D print the part in a weak / low temperature polymer, pack that in the casting sand, and it burns away when you pour the casting. Single use, of course, so it depends how much cost and time is involved to 3D print the part (positive mold), but you end up with your final part in aluminum or bronze and can finish it with ordinary metalworking techniques.</p>
<p dir="ltr">Sean<br>
</p>
<br><br><div class="gmail_quote">On April 14, 2017 6:42:04 AM MDT, Cliff Redus via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<div dir="ltr"><div>Emile, I am interested in the work you did on 3D printing of a thruster prop using ABS. Can give us more detail? Did you use an online service to print the prop? What was the cost? Did you work off a 3-D model file like a STEP file? What was the surface finish? What incremental steps did you have to make (surface finish, machinating...) before mounting? Did you explore any other materials than ABS? How well has the prop held up? How well do you think the ABS will handle UV?</div><div><br /></div><div>Best Regards</div><div><br /></div><div>Cliff</div></div><div class="gmail_extra"><br /><div class="gmail_quote">On Fri, Apr 14, 2017 at 4:35 AM, emile via Personal_Submersibles <span dir="ltr"><<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>></span> wrote:<br /><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Alan,<br />
<br />
The propellor from my rimdrive thruster is 3D printed in ABS.<br />
Seems strong enough.<br />
<br />
Emile<br />
<br />
-----Oorspronkelijk bericht-----<br />
Van: Personal_Submersibles [mailto:<a href="mailto:personal_submersibles-bounces@psubs.org">personal_submersibles-<wbr />bounces@psubs.org</a>]<br />
Namens Alan via Personal_Submersibles<br />
Verzonden: vrijdag 14 april 2017 3:24<br />
Aan: Personal Submersibles General Discussion<br />
Onderwerp: Re: [PSUBS-MAILIST] Plastic Propeller<br />
<br />
Thanks Ian, Greg & Hank.<br />
Ian, I hadn't thought of that 2 propeller type bow thruster as a left hand<br />
propeller source. I will track one down & test it. I can always trim the<br />
diameter down a bit if it is in the ball park. The price isn't too bad<br />
either. If we could print our own propellers, that would be awsome.<br />
Greg, the motors I am using are rated for 50 Amps continuous & I am using<br />
a direct drive. In my calculations, I would need to go to a really low pitch<br />
prop if I went to a larger diameter, & I haven't seen anything that low. I<br />
was using a 7&1/4" 2hp Yamaha prop for testing & it only drew 33 amps. It<br />
will be a matter of pool testing a few of these props & finding a good<br />
economy of Amp draw & thrust but it is being dictated to a degree by what I<br />
can get in right & left hand.<br />
Hank, looking at these propellers again, it would be very difficult to<br />
cast them.<br />
If I made a silicone mold I'd never get the part out. It would also be<br />
difficult to get resin in to the blade area & get air out.<br />
Found out that the new motors I ordered are being used commercially on<br />
electric surf boards, so I can't be too far off track.<br />
Cheers Alan<br />
<br />
<br />
<br />
<br />
Sent from my iPad<br />
<br />
> On 14/04/2017, at 12:32 PM, irox via Personal_Submersibles<br />
<<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.<wbr />org</a>> wrote:<br />
><br />
><br />
> Hi Alan,<br />
><br />
> it might be a bit big for you, but the smallest cheap counter rotating<br />
> prop set I've found is from "Quick", they do a 4 blade 185mm in RH and<br />
> LH for $40-$80 (depending on where you order them). Part numbers:<br />
> BTQ185 LH (QI55507)<br />
> BTQ185 RH (QI55508)<br />
><br />
> <a href="http://www.quickusastore.com/bow-thrusters/spare-parts/bow-thrusters-p" target="_blank" rel="noreferrer">http://www.quickusastore.com/<wbr />bow-thrusters/spare-parts/bow-<wbr />thrusters-p</a><br />
> ropellers.html<br />
><br />
> I got a pair and installed the on cheap ($45) trolling motors. They made<br />
a big difference over the stock props, but of would probably burn out the<br />
cheap trolling motors quickly. I didn't get around to look into reducing<br />
the diameter to better match the motors (plus I want to use better motors<br />
anyway).<br />
><br />
> An SLA 3D Printer may be able to print something which could be used<br />
(after UV curing).<br />
><br />
> Cheers,<br />
> Ian.<br />
><br />
> -----Original Message-----<br />
>> From: Alan via Personal_Submersibles<br />
>> <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.<wbr />org</a>><br />
>> Sent: Apr 13, 2017 4:52 PM<br />
>> To: <a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.<wbr />org</a><br />
>> Subject: [PSUBS-MAILIST] Plastic Propeller<br />
>><br />
>> Greg, (or anyone else as knowledgeable) I am going to test a Vetus<br />
>> 146mm propeller soon. On paper it seems a good match to my motor. I<br />
>> have not seen a left hand prop (which I<br />
>> need) & the right hands go between $56- & $100-. Also I may need a<br />
>> slightly smaller diameter. They are made of delrin.<br />
>> Is there an easy / inexpensive way of replicating something similar?<br />
>> I was thinking they could be printed & the print used as a lost wax<br />
>> type aluminium casting.<br />
>> I could make a silicon mold from a print & cast a fiber reinforced<br />
>> propeller, but aren't sure about the strength & quality I could get.<br />
>> Any thoughts on the best way of doing this?<br />
>> Thanks, Alan<br />
>><br />
>><br />
>> Sent from my iPad<br />
>><br />
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