View Full Version : What is UHU glue???
I'm starting to build my Ikarus shockflyer and it calls for 10 minute UHU glue. Can someone tell me what it is and/or direct me to a good alternative?
I believe it's contact cement. Can I use a foam-safe CA instead or is it too brittle where the UHU glue will bend and flex some?
Also, I'm building a CDR motor for it from gobrushless.com. Anyone have a good starting recommendation for wire size and number of winds?
As always, thanks in advance for you help...
...Rick
smoothound
19.10.04, 19:52
Not a lot of help but UHU glues (http://www.saunders-usa.com/uhu/cat.cfm?cat_id=9013)
I think it is just contact cement as you say but someone who's built one will be along soon /ubbthreads/images/graemlins/grin.gif
Hi rick,
UHU is a make of glue, over here we have something called UHU POR for foam safe stuff which is as you say a contact adhesive. I think over that side of the pond you have UHU Creativ or something like that which is the same thing.
I normally use foam safe CA or Epoxy for stronger joints.
wind of your motor depends on prop you intend using and most importantly what cells.
Hi, UHU is just a brand of glue, UHU POR being very good for depron. You should have had a small tube of UHU POR in with your Shockie kit? I've used foam friendly CA on my shockies but like you mentioned it is a little bit brittle, where as the UHU does give a little in a hard landing/crash /ubbthreads/images/graemlins/wink.gif. I currently use a glue called "Foam2Foam" made by Deluxe Materials (http://www.deluxematerials.com) which is as good as UHU POR I find. You might be able to get UHU POR from a office supplies type store.
Good Luck
I type too slow, 2 replys in time I typed this /ubbthreads/images/graemlins/smile.gif
PS. You'll find the `Foam2Foam` glue in the new items section.
Crash - the 10 minutes it refers to just means leave the UHU spread on both surfaces for 10 minutes before you assemble. You can use UHU POR as a "standard glue - slap it on and stick together, or you can use it as a contact glue - spread on both bits thinly, leave for 10 minutes then once tacky slap em together for an instant strong bond.
If it's a genuine Shocky it should have had a tube of UHU por in the box.
As per scoots suggestion - tell use the cells and config you are looking for and we can give you some tips - on 3 cells I am running 19 turns of 25 guage in wye format which is simply ballistic.
Thanks guys, I'll double check for the UHU POR as it's an Ikarus kit, otherwise I'll hit the hobby shop to see what they have in contact cement or go with foam-safe CA which I have. Would like to test contact cement to see how it works.
Regarding a CDR motor, it's all new to me, and I'm using JJ's site and gobrushless.com to try and figure something out. I do have a Phoenix 10 for it, that much I can tell you, lol.
So to help you help me, I already have 2 cell 640 lith packs that I'd like to use. They are the newer high capacity cells, I think 8C, but I'm not at home to check. The CDR kit as seen HERE (http://www.gobrushless.com/ccp51/cgi-bin/cp-app.cgi?usr=51F4251309&rnd=3146345&rrc=N&affl=&cip =198.70.20.20&act=&aff=&pg=cat&ref=diy+brushless+k its) uses 26 guage Newbie wire (lol) so I would probably start with that. Any recommendations on number of winds and prop would be greatly appreciated. In addition, I have purchased several spools of wire from Radio Shack in 3 different guages, and will experiment in time.
So for now, I guess it's 2 cell 640 liths and 26 guage wire. What yall recommend, and thanks againl...
Oh yeah, how do I mount this silly thing???
...Rick
Hi Rick, really not sure on the windings, as there are plenty of variables I haven't explored. It will likely be sub-20 turns for a 9x5 prop for a "Y" or star wound motor. I'll see what I can find.
Mounting will depend on how you build the motor, if there isn't a firewall to mount on, then build it with a long tube centre in the motor and this can be cable tied to a rod along the fuselage. Lots of posts (too many!) on rcgroups.
BFN
OK - prop wise, we've had the greatest success on GWS 8x4DD's - note the DD might be called HD where you are - it's not the standard slowfly one, it's been made specifically for direct drive's like CDRom's and is far more efficient in this sort of use. On the motor, depending on how hot you want it I would go for between 13 and 17 turns of 24 or 25 guage if you have it in WYE wind. If you really want to stick with the 26 guage you are going to be a bit empty on the teeth - not too important for a first attempt but it will cut efficiency - you could always convert to 22 to 27 turn delta with the 26 guage to get a similar range (to go from wye to delta times the wye turn count by 1.74) The more wire you can slap in there, the more efficient, the less current you will pull for your desired results. Dont worry if WOT is slightly above the packs ability - believe me you're hardly ever going to go need full throttle!
On the mounting - as JJ says, if you are not going for a firewall approach get a piece of tube (CF or thin wall ally) that the motor will fit tightly into, then put a 3 or so inch section into the fuzz
Another glue worth looking for is Zap A-Dap-A Goo II......I actually prefer this to UHU POR - but they both do a good job.
Michael's craft store has it.
OK, thanks all. And wouldn't you know it, I go to Hobby People, very large RC chain here in the US, and they are out of that Zap-a-Goo stuff as well as foam safe CA. Only a 22 mile drive... fortunately I have another H.P. within 20 miles in the other direction I can try later today after church.
Re: winds, since the kit came with 26 guage Newbie Wire I think I'll start with as many turns as I can get with their kit. I have 20 and 32 guage wire for future motor testing.
The airplane kit came with a 9x47 prop, but I have many other props available if you guys don't think it will work well with the CDR motor.
In a nutshell, I'm starting with a 9x47 prop, CDR motor with as many winds as possible using 26ga wire. Stop me now if I'm going astray! Oh, and I'm starting out with a 2C lith pack, switching to a 3 cell pack with future motors.
Thanks much... Rick...
If you are going to go 2c pack, and are using the 26 guage, and want to cram as much as you can get on, then you will probably end up going delta wind to get good performance. You should be able to get around 23 or 24 turns of 26 guage on there, which in wye wind will give relatively low KV, which on 2c is not going to spin that prop very quickly. 23 to 24 delta is on the other hand probably going to be a *little* on the hot side - equivelant to about 13 turns wye - but you will probably be nearer the power band you'll be looking for to get the most out the shocky - make sure you check current draw carefully though!
Thanks. I knew there was a difference in the power band between Delta and Wye configurations, I didn't realize it was that significant. As a starting point I'll give the Delta a shot since you're thinking it will bring me into an acceptable power band.
With a Delta wind, being there is no common ground, I'm guessing the 3 leads just go directly to the brushless controller leads???
How many amps do you think this little CDR will pull with a 9x47 prop? Is there a chance I'll exceed the capacity of my liths? My 2 cell 640's are 8C, so I'm thinkin' it won't be an issue.
...Rick
Delta.
The end of phase 1 joins the start of phase 2, the end of 2 joins the start of 3, the end of 3 joins the start of 1. The three joins is where each of the ESC wires connect.
When I intend to wind in Delta I use one continuos wire. Wind the first phase then loop down and back up to wind the second phase then loop down and back up for the third. this will leave you with two open ends which join to one ESC wire, the loops join to the other two ESC wires.
Hope that makes sense /ubbthreads/images/graemlins/smile.gif
Here are a few links to PDF tutorials on gobrushless website. (http://www.gobrushless.com) Tutorial link (http://www.gobrushless.com/GBL_single_v2.pdf) Trouble shooting guide (http://www.gobrushless.com/GBL_single_troubleshooting.pdf)
http://www.ikarus-modellbau.de/uploads/attach/410408-windings.jpg
hmmm - 640 at 8c is only 5.1 amps. You might be pushing it a little bit at WOT, but of course you very rarely need WOT. Most of the time you will be at more like 50% or less. Should think you will get away with it!
Thanks Mike, I have been using the GoBrushless tutorial and JJ's site.
So with the Wye, the 3 ends of the phases that are tied together, do they go to battery ground, or do they just float tied together?
I like your idea of using one continuous run for all 3 phases of your Delta wind. Neat idea. How much of a loop do you lead from the end of one phase to the start of the other? I'm guessing you want at least an inch of lead when done.
...Rick
yes, with Wye, the three ends are soldered together and then float in the motor, they dont go anywhere!
Yeah about an inch will do, you dont want it too long as the enamel wire doesn't like too much flexing. Try to support the wires as they exit the motor and join the esc wires, I've had one or two fail at this point after the abuse I gave them, all in the name of testing mind /ubbthreads/images/graemlins/wink.gif.
Have a look at the solder plate here. (http://www.brushlessmotors.co.uk/shop.php?id=9) I've made similar plates from old circuit board material, not as neat as the ones from C&K but it solved the wire fracturing problem.
The three joined wires in a Wye motor I always put a piece of heat shrink to insulate it from the stator, I'm not 100% sure but I would imagine a short between wind and stator would be a bad thing.
OK, thanks Dongle and Mike, appreciate your time. I love that brushless site, now that's some trick stuff they offer. /ubbthreads/images/graemlins/cool.gif I may have to order up a few items /ubbthreads/images/graemlins/smile.gif
Something is telling me I'll be switching to a 3 cell pack rather quickly, so if the 2 cell 640's won't handle the current, no problem. Everything I hear is that CDR's go balistic on 3 cells, I was just trying to get into it with what I have.
OK, so I'm working through it with everyone's help, so like how do I mount the prop? Looks like some sort of prop saver hub is in order. I'll check around Balsa Products, they seem to have a lot of electric stuff.
...Rick
The prop adaptor can be a servo horn forced onto the shaft or a wheel collet which you drill a second hole opposite the existing one.
http://www.ikarus-modellbau.de/uploads/attach/410446-servo-horn-adapt.jpg
http://www.ikarus-modellbau.de/uploads/attach/410446-wheel-collet-addapt.jpg
http://www.ikarus-modellbau.de/uploads/attach/410446-prop-addapt.jpg
Cool /ubbthreads/images/graemlins/cool.gif You DIY guys are magical /ubbthreads/images/graemlins/wink.gif
...Rick
You know I had totally forgotten about servo horns for prop mounts! I've just spent an hour turning one up as well /ubbthreads/images/graemlins/tongue.gif
Dont be tooo quick to discount the 2 cells - on such a light plane they still can be great performers. True, I have never got the power I like from them, but then I always go way over the top with my power requirements /ubbthreads/images/graemlins/wink.gif /ubbthreads/images/graemlins/grin.gif I've just made three large motors trying to find the ideal combo CDRom to get as close to 1kg thrust for less than 10 amps, still a 100g or so short, but getting there!
I agree with Dongle about the 2 cell set up. My favorite setup is a CDrom wound 32SWG 32Turn in Delta on 2 x 340 Kokams. On the same motor I run a 1200 2 cell pack which has more than enough power to hover but doesn't have the brute force for the pullouts as the lighter pack, still awesome all the same.
Well OK, it sounds promising on 2 cell packs as well. I also have a couple 20C 340mAh packs, and enough material to make 3 CDR's, so I'm thinking Mike's 32T CDR motor on 2 cell 340's will be my second build.
Thanks Kelly, I'll check Michaels. I did find UHU POR at Hobby Lobby, but it's mail order. If I can't find it at a local Hobby People or Michaels tonight then I'll order some up.
JJ, I visited your site last night, CDR section, I really appreciate the work you did for us. I didn't dare visit the shed though /ubbthreads/images/graemlins/shocked.gif You need an autograph book on your website so we can leave our mark when passing through /ubbthreads/images/graemlins/laugh.gif Or at least answer the door when we knock /ubbthreads/images/graemlins/tongue.gif
...Rick
Thanks Scoot & Kelly, found UHU Creativ glue at Michaels. So I'm all set to start my motor and the shockflyer. I'll start a new post if (I mean when) I have more questions...
...Rick
Needs an update, Rick... just like the shed needs a new roof /ubbthreads/images/graemlins/wink.gif
I haven't done much fixed wing motor work yet, the guys posting here are more informed on the motor applications. Catch you later, glueing to do, magnets to swear at.
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